-
<!doctype linuxdoc system>
<article>
<title>ca65 Users Guide
<author>Ullrich von Bassewitz, <htmlurl url="mailto:uz@cc65.org" name="uz@cc65.org">
-<date>19.07.2000, 29.11.2000, 02.10.2001
+<date>2000-07-19, 2000-11-29, 2001-10-02, 2005-09-08
<abstract>
ca65 is a powerful macro assembler for the 6502, 65C02 and 65816 CPUs. It is
Usage: ca65 [options] file
Short options:
-D name[=value] Define a symbol
- -I dir Set an include directory search path
- -U Mark unresolved symbols as import
- -V Print the assembler version
- -W n Set warning level n
- -g Add debug info to object file
- -h Help (this text)
- -i Ignore case of symbols
- -l Create a listing if assembly was ok
- -o name Name the output file
- -s Enable smart mode
- -t sys Set the target system
- -v Increase verbosity
+ -I dir Set an include directory search path
+ -U Mark unresolved symbols as import
+ -V Print the assembler version
+ -W n Set warning level n
+ -g Add debug info to object file
+ -h Help (this text)
+ -i Ignore case of symbols
+ -l Create a listing if assembly was ok
+ -mm model Set the memory model
+ -o name Name the output file
+ -s Enable smart mode
+ -t sys Set the target system
+ -v Increase verbosity
Long options:
--auto-import Mark unresolved symbols as import
- --cpu type Set cpu type
+ --cpu type Set cpu type
--debug-info Add debug info to object file
- --feature name Set an emulation feature
- --help Help (this text)
+ --feature name Set an emulation feature
+ --help Help (this text)
--ignore-case Ignore case of symbols
--include-dir dir Set an include directory search path
- --listing Create a listing if assembly was ok
+ --listing Create a listing if assembly was ok
+ --list-bytes n Maximum number of bytes per listing line
+ --macpack-dir dir Set a macro package directory
+ --memory-model model Set the memory model
--pagelength n Set the page length for the listing
- --smart Enable smart mode
- --target sys Set the target system
- --verbose Increase verbosity
- --version Print the assembler version
+ --smart Enable smart mode
+ --target sys Set the target system
+ --verbose Increase verbosity
+ --version Print the assembler version
---------------------------------------------------------------------------
</verb></tscreen>
<descrip>
+ <label id="option--cpu">
<tag><tt>--cpu type</tt></tag>
Set the default for the CPU type. The option takes a parameter, which
may be one of
- 6502, 65C02, 65816 and sunplus
+ 6502, 65SC02, 65C02, 65816, sunplus, sweet16, HuC6280
- The latter (sunplus) is not available in the freeware version, because the
- instruction set of the sunplus CPU is "confidential".
+ The sunplus cpu is not available in the freeware version, because the
+ instruction set is "proprietary and confidential".
<label id="option--feature">
<tag><tt>-i, --ignore-case</tt></tag>
This option makes the assembler case insensitive on identifiers and labels.
- This option will override the default, but may itself be overriden by the
+ This option will override the default, but may itself be overridden by the
<tt><ref id=".CASE" name=".CASE"></tt> control command.
may change in future versions.
+ <tag><tt>--list-bytes n</tt></tag>
+
+ Set the maximum number of bytes printed in the listing for one line of
+ input. See the <tt><ref id=".LISTBYTES" name=".LISTBYTES"></tt> directive
+ for more information. The value zero can be used to encode an unlimited
+ number of printed bytes.
+
+
+ <tag><tt>--macpack-dir dir</tt></tag>
+
+ This options allows to specify a directory containing macro files that are
+ used instead of the builtin images when a <tt><ref id=".MACPACK"
+ name=".MACPACK"></tt> directive is encountered. If <tt>--macpack-dir</tt>
+ was specified, a <tt>.mac</tt> extension is added to the package name and
+ the resulting file is loaded from the given directory. This is most useful
+ when debugging the builtin macro packages.
+
+
+ <tag><tt>-mm model, --memory-model model</tt></tag>
+
+ Define the default memory model. Possible model specifiers are near, far and
+ huge.
+
+
<tag><tt>-o name</tt></tag>
The default output name is the name of the input file with the extension
Name a directory which is searched for include files. The option may be
used more than once to specify more than one directory to search. The
current directory is always searched first before considering any
- additional directores.
+ additional directories.
<tag><tt>-U, --auto-import</tt></tag>
<sect>Input format<p>
+<sect1>Assembler syntax<p>
+
The assembler accepts the standard 6502/65816 assembler syntax. One line may
contain a label (which is identified by a colon), and, in addition to the
label, an assembler mnemonic, a macro, or a control command (see section <ref
id="control-commands" name="Control Commands"> for supported control
-commands). Alternatively, the line may contain a symbol definition using the
-'=' token. Everything after a semicolon is handled as a comment (that is, it
-is ignored).
+commands). Alternatively, the line may contain a symbol definition using
+the '=' token. Everything after a semicolon is handled as a comment (that is,
+it is ignored).
Here are some examples for valid input lines:
MaSym = Label ; Another symbol
</verb></tscreen>
-The assembler accepts all valid 6502 mnemonics when in 6502 mode (the
-default). The assembler accepts all valid 65SC02 mnemonics when in 65SC02 mode
-(after a <tt><ref id=".PC02" name=".PC02"></tt> command is found). The
-assembler accepts all valid 65816 mnemonics with a few exceptions after a
-.P816 command is found. These exceptions are listed below.
+The assembler accepts
+
+<itemize>
+<item>all valid 6502 mnemonics when in 6502 mode (the default or after the
+ <tt><ref id=".P02" name=".P02"></tt> command was given).
+<item>all valid 6502 mnemonics plus a set of illegal instructions when in
+ <ref id="6502X-mode" name="6502X mode">.
+<item>all valid 65SC02 mnemonics when in 65SC02 mode (after the
+ <tt><ref id=".PSC02" name=".PSC02"></tt> command was given).
+<item>all valid 65C02 mnemonics when in 65C02 mode (after the
+ <tt><ref id=".PC02" name=".PC02"></tt> command was given).
+<item>all valid 65618 mnemonics when in 65816 mode (after the
+ <tt><ref id=".P816" name=".P816"></tt> command was given).
+<item>all valid SunPlus mnemonics when in SunPlus mode (after the
+ <tt><ref id=".SUNPLUS" name=".SUNPLUS"></tt> command was given).
+</itemize>
+
+
+<sect1>65816 mode<p>
In 65816 mode several aliases are accepted in addition to the official
mnemonics:
DEA is an alias for DEC A
INA is an alias for INC A
SWA is an alias for XBA
- TAD is an alias for TCD
+ TAD is an alias for TCD
TAS is an alias for TCS
TDA is an alias for TDC
TSA is an alias for TSC
</verb></tscreen>
-Evaluation of banked expressions in 65816 mode differs slightly from the
-official syntax:
-Instead of accepting a 24 bit address (something that is difficult for
-the assembler to determine and would have required one more special
-.import command), the bank and the absolute address in that bank are
-separated by a dot:
-<tscreen><verb>
- jsl 3.$1234 ; Call subroutine at $1234 in bank 3
-</verb></tscreen>
+<sect1>6502X mode<label id="6502X-mode"><p>
-For literal values, the assembler accepts the widely used number formats:
-A preceeding '$' denotes a hex value, a preceeding '%' denotes a
-binary value, and a bare number is interpeted as a decimal. There are
-currently no octal values and no floats.
-<p>
+6502X mode is an extension to the normal 6502 mode. In this mode, several
+mnemonics for illegal instructions of the NMOS 6502 CPUs are accepted. Since
+these instructions are illegal, there are no official mnemonics for them. The
+unofficial ones are taken from <htmlurl
+url="http://oxyron.net/graham/opcodes02.html"
+name="http://oxyron.net/graham/opcodes02.html">. Please note that only the
+ones marked as "stable" are supported. The following table uses information
+from the mentioned web page, for more information, see there.
+
+<itemize>
+<item><tt>ALR: A:=(A and #{imm})*2;</tt>
+<item><tt>ANC: A:=A and #{imm};</tt> Generates opcode $0B.
+<item><tt>ARR: A:=(A and #{imm})/2;</tt>
+<item><tt>AXS: X:=A and X-#{imm};</tt>
+<item><tt>DCP: {adr}:={adr}-1; A-{adr};</tt>
+<item><tt>ISC: {adr}:={adr}+1; A:=A-{adr};</tt>
+<item><tt>LAS: A,X,S:={adr} and S;</tt>
+<item><tt>LAX: A,X:={adr};</tt>
+<item><tt>RLA: {adr}:={adr}rol; A:=A and {adr};</tt>
+<item><tt>RRA: {adr}:={adr}ror; A:=A adc {adr};</tt>
+<item><tt>SAX: {adr}:=A and X;</tt>
+<item><tt>SLO: {adr}:={adr}*2; A:=A or {adr};</tt>
+<item><tt>SRE: {adr}:={adr}/2; A:=A xor {adr};</tt>
+</itemize>
+
+
+
+<sect1>sweet16 mode<label id="sweet16-mode"><p>
+
+SWEET 16 is an interpreter for a pseudo 16 bit CPU written by Steve Wozniak
+for the Apple ][ machines. It is available in the Apple ][ ROM. ca65 can
+generate code for this pseudo CPU when switched into sweet16 mode. The
+following is special in sweet16 mode:
+
+<itemize>
+
+<item>The '@' character denotes indirect addressing and is no longer available
+for cheap local labels. If you need cheap local labels, you will have to
+switch to another lead character using the <tt/<ref id=".LOCALCHAR"
+name=".LOCALCHAR">/ command.
+
+<item>Registers are specified using <tt/R0/ .. <tt/R15/. In sweet16 mode,
+these identifiers are reserved words.
+
+</itemize>
+
+Please note that the assembler does neither supply the interpreter needed for
+SWEET 16 code, nor the zero page locations needed for the SWEET 16 registers,
+nor does it call the interpreter. All this must be done by your program. Apple
+][ programmers do probably know how to use sweet16 mode.
+
+For more information about SWEET 16, see
+<htmlurl url="http://www.6502.org/source/interpreters/sweet16.htm"
+name="http://www.6502.org/source/interpreters/sweet16.htm">.
+
+
+<sect1>Number format<p>
+
+For literal values, the assembler accepts the widely used number formats: A
+preceding '$' or a trailing 'h' denotes a hex value, a preceding '%'
+denotes a binary value, and a bare number is interpreted as a decimal. There
+are currently no octal values and no floats.
+
+
+<sect1>Conditional assembly<p>
+
+Please note that when using the conditional directives (<tt/.IF/ and friends),
+the input must consist of valid assembler tokens, even in <tt/.IF/ branches
+that are not assembled. The reason for this behaviour is that the assembler
+must still be able to detect the ending tokens (like <tt/.ENDIF/), so
+conversion of the input stream into tokens still takes place. As a consequence
+conditional assembly directives may <bf/not/ be used to prevent normal text
+(used as a comment or similar) from being assembled. <p>
<sect>Expressions<p>
linker.
-<sect1>Size of an expression
s result<p>
+<sect1>Size of an expression result<p>
Sometimes, the assembler must know about the size of the value that is the
result of an expression. This is usually the case, if a decision has to be
<item> If the result of an expression is constant, the actual value is
checked to see if it's a byte sized expression or not.
<item> If the expression is explicitly casted to a byte sized expression by
- one of the '>'/'<' operators, it is a byte expression.
+ one of the '>', '<' or '^' operators, it is a byte expression.
<item> If this is not the case, and the expression contains a symbol,
explicitly declared as zero page symbol (by one of the .importzp or
.exportzp instructions), then the whole expression is assumed to be
In the context of a boolean expression, any non zero value is evaluated as
true, any other value to false. The result of a boolean expression is 1 if
-it's true, and zero if it's false. There are boolean operators with extrem
+it's true, and zero if it's false. There are boolean operators with extreme
low precedence with version 2.x (where x > 0). The <tt/.AND/ and <tt/.OR/
operators are shortcut operators. That is, if the result of the expression is
already known, after evaluating the left hand side, the right hand side is
not evaluated.
-<sect1>Available operators<p>
-
-Available operators sorted by precedence:
-
-<tscreen><verb>
- Op Description Precedence
- -------------------------------------------------------------------
- .CONCAT Builtin function 0
- .LEFT Builtin function 0
- .MID Builtin function 0
- .RIGHT Builtin function 0
- .STRING Builtin function 0
-
- * Builtin pseudo variable (r/o) 1
- .BLANK Builtin function 1
- .CONST Builtin function 1
- .CPU Builtin pseudo variable (r/o) 1
- .DEFINED Builtin function 1
- .MATCH Builtin function 1
- .TCOUNT Builtin function 1
- .TIME Builtin function 1
- .XMATCH Builtin function 1
- .PARAMCOUNT Builtin pseudo variable (r/o) 1
- .REFERENCED Builtin function 1
- :: Global namespace override 1
- + Unary plus 1
- - Unary minus 1
- ~ Unary bitwise not 1
- .BITNOT Unary bitwise not 1
- < Low byte operator 1
- > High byte operator 1
-
- * Multiplication 2
- / Division 2
- .MOD Modulo operation 2
- & Bitwise and 2
- .BITAND Bitwise and 2
- ^ Bitwise xor 2
- .BITXOR Bitwise xor 2
- << Shift left operator 2
- .SHL Shift left operator 2
- >> Shift right operator
- .SHR Shift right operator 2
-
- + Binary plus 3
- - Binary minus 3
- | Binary or 3
- .BITOR Binary or 3
-
- = Compare operation (equal) 4
- <> Compare operation (not equal) 4
- < Compare operation (less) 4
- > Compare operation (greater) 4
- <= Compare operation (less or equal) 4
- >= Compare operation (greater or equal) 4
-
- && Boolean and 5
- .AND Boolean and 5
- .XOR Boolean xor 5
-
- || Boolean or 6
- .OR Boolean or 6
-
- ! Boolean not 7
- .NOT Boolean not 7
-</verb></tscreen>
-
-
-To force a specific order of evaluation, braces may be used as usual.
-
-Some of the pseudo variables mentioned above need some more explanation:
-
-<tscreen><verb>
- * This symbol is replaced by the value of the program
- counter at start of the current instruction. Note, that
- '*' yields a rvalue, that means, you cannot assign to it.
- Use <tt/.ORG/ to set the program counter in sections with
- absolute code.
-</verb></tscreen>
-<p>
+<sect1>Constant expressions<p>
+
+Sometimes an expression must evaluate to a constant without looking at any
+further input. One such example is the <tt/<ref id=".IF" name=".IF">/ command
+that decides if parts of the code are assembled or not. An expression used in
+the <tt/.IF/ command cannot reference a symbol defined later, because the
+decision about the <tt/.IF/ must be made at the point when it is read. If the
+expression used in such a context contains only constant numerical values,
+there is no problem. When unresolvable symbols are involved it may get harder
+for the assembler to determine if the expression is actually constant, and it
+is even possible to create expressions that aren't recognized as constant.
+Simplifying the expressions will often help.
+
+In cases where the result of the expression is not needed immediately, the
+assembler will delay evaluation until all input is read, at which point all
+symbols are known. So using arbitrary complex constant expressions is no
+problem in most cases.
+
+
+
+<sect1>Available operators<label id="operators"><p>
+
+<table>
+<tabular ca="clc">
+<bf/Operator/| <bf/Description/| <bf/Precedence/@<hline>
+| Built-in string functions| 0@
+||~@
+| Built-in pseudo-variables| 1@
+| Built-in pseudo-functions| 1@
++| Unary positive| 1@
+-| Unary negative| 1@
+˜<newline>
+.BITNOT| Unary bitwise not| 1@
+<<newline>
+.LOBYTE| Unary low-byte operator| 1@
+><newline>
+.HIBYTE| Unary high-byte operator| 1@
+^<newline>
+.BANKBYTE| Unary bank-byte operator| 1@
+||~@
+*| Multiplication| 2@
+/| Division| 2@
+.MOD| Modulo operator| 2@
+&<newline>
+.BITAND| Bitwise and| 2@
+^<newline>
+.BITXOR| Binary bitwise xor| 2@
+<<<newline>
+.SHL| Shift-left operator| 2@
+>><newline>
+.SHR| Shift-right operator| 2@
+||~@
++| Binary addition| 3@
+-| Binary subtraction| 3@
+|<newline>
+.BITOR| Bitwise or| 3@
+||~@
+= | Compare operator (equal)| 4@
+<>| Compare operator (not equal)| 4@
+<| Compare operator (less)| 4@
+>| Compare operator (greater)| 4@
+<=| Compare operator (less or equal)| 4@
+>=| Compare operator (greater or equal)| 4@
+||~@
+&&<newline>
+.AND| Boolean and| 5@
+.XOR| Boolean xor| 5@
+||~@
+||<newline>
+.OR| Boolean or| 6@
+||~@
+!<newline>
+.NOT| Boolean not| 7@<hline>
+</tabular>
+<caption>Available operators, sorted by precedence
+</table>
+
+To force a specific order of evaluation, parentheses may be used, as usual.
<sect1>Numeric constants<p>
-Numeric constants are defined using the equal sign. After doing
+Numeric constants are defined using the equal sign or the label assignment
+operator. After doing
<tscreen><verb>
two = 2
</verb></tscreen>
may use the symbol "two" in every place where a number is expected, and it is
-evaluated to the value 2 in this context. An example would be
+evaluated to the value 2 in this context. The label assignment operator causes
+the same, but causes the symbol to be marked as a label, which may cause a
+different handling in the debugger:
+
+<tscreen><verb>
+ io := $d000
+</verb></tscreen>
+
+The right side can of course be an expression:
<tscreen><verb>
four = two * two
dey
bne @Loop ; Ok
rts
- Sub: ... ; New global label
- bne @Loop ; ERROR: Unknown identifier!
+ Sub: ... ; New global label
+ bne @Loop ; ERROR: Unknown identifier!
</verb></tscreen>
<sect1>Unnamed labels<p>
-If you really want to write messy code, there are also unnamed
-labels. These labels do not have a name (you guessed that already,
-didn't you?). A colon is used to mark the absence of the name.
+If you really want to write messy code, there are also unnamed labels. These
+labels do not have a name (you guessed that already, didn't you?). A colon is
+used to mark the absence of the name.
-Unnamed labels may be accessed by using the colon plus several minus
-or plus characters as a label designator. Using the '-' characters
-will create a back reference (use the n'th label backwards), using
-'+' will create a forward reference (use the n'th label in forward
-direction). An example will help to understand this:
+Unnamed labels may be accessed by using the colon plus several minus or plus
+characters as a label designator. Using the '-' characters will create a back
+reference (use the n'th label backwards), using '+' will create a forward
+reference (use the n'th label in forward direction). An example will help to
+understand this:
<tscreen><verb>
: lda (ptr1),y ; #1
-<sect>Control commands<label id="control-commands">
+<sect>Scopes<label id="scopes"><p>
-<p>
-Here's a list of all control commands and a description, what they do:
+ca65 implements several sorts of scopes for symbols.
+<sect1>Global scope<p>
-<sect1><tt>.A16</tt><label id=".A16"><p>
+All (non cheap local) symbols that are declared outside of any nested scopes
+are in global scope.
- Valid only in 65816 mode. Switch the accumulator to 16 bit.
- Note: This command will not emit any code, it will tell the assembler to
- create 16 bit operands for immediate accumulator adressing mode.
+<sect1>Cheap locals<p>
- See also: <tt><ref id=".SMART" name=".SMART"></tt>
+A special scope is the scope for cheap local symbols. It lasts from one non
+local symbol to the next one, without any provisions made by the programmer.
+All other scopes differ in usage but use the same concept internally.
-<sect1>
<tt>.A8</tt><label id=".A8"><p>
+<sect1>
Generic nested scopes<p>
- Valid only in 65816 mode. Switch the accumulator to 8 bit.
+A nested scoped for generic use is started with <tt/<ref id=".SCOPE"
+name=".SCOPE">/ and closed with <tt/<ref id=".ENDSCOPE" name=".ENDSCOPE">/.
+The scope can have a name, in which case it is accessible from the outside by
+using <ref id="scopesyntax" name="explicit scopes">. If the scope does not
+have a name, all symbols created within the scope are local to the scope, and
+aren't accessible from the outside.
- Note: This command will not emit any code, it will tell the assembler to
- create 8 bit operands for immediate accu adressing mode.
+A nested scope can access symbols from the local or from enclosing scopes by
+name without using explicit scope names. In some cases there may be
+ambiguities, for example if there is a reference to a local symbol that is not
+yet defined, but a symbol with the same name exists in outer scopes:
- See also: <tt><ref id=".SMART" name=".SMART"></tt>
+<tscreen><verb>
+ .scope outer
+ foo = 2
+ .scope inner
+ lda #foo
+ foo = 3
+ .endscope
+ .endscope
+</verb></tscreen>
+In the example above, the <tt/lda/ instruction will load the value 3 into the
+accumulator, because <tt/foo/ is redefined in the scope. However:
-<sect1><tt>.ADDR</tt><label id=".ADDR"><p>
+<tscreen><verb>
+ .scope outer
+ foo = $1234
+ .scope inner
+ lda foo,x
+ foo = $12
+ .endscope
+ .endscope
+</verb></tscreen>
- Define word sized data. In 6502 mode, this is an alias for <tt/.WORD/ and
- may be used for better readability if the data words are address values. In
- 65816 mode, the address is forced to be 16 bit wide to fit into the current
- segment. See also <tt><ref id=".FARADDR" name=".FARADDR"></tt>. The command
- must be followed by a sequence of (not necessarily constant) expressions.
+Here, <tt/lda/ will still load from <tt/$12,x/, but since it is unknown to the
+assembler that <tt/foo/ is a zeropage symbol when translating the instruction,
+absolute mode is used instead. In fact, the assembler will not use absolute
+mode by default, but it will search through the enclosing scopes for a symbol
+with the given name. If one is found, the address size of this symbol is used.
+This may lead to errors:
- Example:
+<tscreen><verb>
+ .scope outer
+ foo = $12
+ .scope inner
+ lda foo,x
+ foo = $1234
+ .endscope
+ .endscope
+</verb></tscreen>
- <tscreen><verb>
- .addr $0D00, $AF13, _Clear
- </verb></tscreen>
+In this case, when the assembler sees the symbol <tt/foo/ in the <tt/lda/
+instruction, it will search for an already defined symbol <tt/foo/. It will
+find <tt/foo/ in scope <tt/outer/, and a close look reveals that it is a
+zeropage symbol. So the assembler will use zeropage addressing mode. If
+<tt/foo/ is redefined later in scope <tt/inner/, the assembler tries to change
+the address in the <tt/lda/ instruction already translated, but since the new
+value needs absolute addressing mode, this fails, and an error message "Range
+error" is output.
- See: <tt><ref id=".FARADDR" name=".FARADDR"></tt>, <tt><ref id=".WORD"
- name=".WORD"></tt>
+Of course the most simple solution for the problem is to move the definition
+of <tt/foo/ in scope <tt/inner/ upwards, so it precedes its use. There may be
+rare cases when this cannot be done. In these cases, you can use one of the
+address size override operators:
+<tscreen><verb>
+ .scope outer
+ foo = $12
+ .scope inner
+ lda a:foo,x
+ foo = $1234
+ .endscope
+ .endscope
+</verb></tscreen>
-<sect1><tt>.ALIGN</tt><label id=".ALIGN"><p>
+This will cause the <tt/lda/ instruction to be translated using absolute
+addressing mode, which means changing the symbol reference later does not
+cause any errors.
- Align data to a given boundary. The command expects a constant integer
- argument that must be a power of two, plus an optional second argument
- in byte range. If there is a second argument, it is used as fill value,
- otherwise the value defined in the linker configuration file is used
- (the default for this value is zero).
- Since alignment depends on the base address of the module, you must
- give the same (or a greater) alignment for the segment when linking.
- The linker will give you a warning, if you don't do that.
+<sect1>Nested procedures<p>
- Example:
+A nested procedure is created by use of <tt/<ref id=".PROC" name=".PROC">/. It
+differs from a <tt/<ref id=".SCOPE" name=".SCOPE">/ in that it must have a
+name, and a it will introduce a symbol with this name in the enclosing scope.
+So
- <tscreen><verb>
- .align 256
- </verb></tscreen>
+<tscreen><verb>
+ .proc foo
+ ...
+ .endscope
+</verb></tscreen>
+is actually the same as
-<sect1><tt>.ASCIIZ</tt><label id=".ASCIIZ"><p>
+<tscreen><verb>
+ foo:
+ .scope foo
+ ...
+ .endscope
+</verb></tscreen>
- Define a string with a trailing zero.
+This is the reason why a procedure must have a name. If you want a scope
+without a name, use <tt/<ref id=".SCOPE" name=".SCOPE">/.
- Example:
+<bf/Note:/ As you can see from the example above, scopes and symbols live in
+different namespaces. There can be a symbol named <tt/foo/ and a scope named
+<tt/foo/ without any conflicts (but see the section titled <ref
+id="scopesearch" name=""Scope search order"">).
- <tscreen><verb>
- Msg: .asciiz "Hello world"
- </verb></tscreen>
- This will put the string "Hello world" followed by a binary zero into
- the current segment. There may be more strings separated by commas, but
- the binary zero is only appended once (after the last one).
+<sect1>Structs, unions and enums<p>
+Structs, unions and enums are explained in a <ref id="structs" name="separate
+section">, I do only cover them here, because if they are declared with a
+name, they open a nested scope, similar to <tt/<ref id=".SCOPE"
+name=".SCOPE">/. However, when no name is specified, the behaviour is
+different: In this case, no new scope will be opened, symbols declared within
+a struct, union, or enum declaration will then be added to the enclosing scope
+instead.
-<sect1><tt>.AUTOIMPORT</tt><label id=".AUTOIMPORT"><p>
- Is followed by a plus or a minus character. When switched on (using a
- +), undefined symbols are automatically marked as import instead of
- giving errors. When switched off (which is the default so this does not
- make much sense), this does not happen and an error message is
- displayed. The state of the autoimport flag is evaluated when the
- complete source was translated, before outputing actual code, so it is
- <em/not/ possible to switch this feature on or off for separate sections
- of code. The last setting is used for all symbols.
+<sect1>Explicit scope specification<label id="scopesyntax"><p>
- You should probably not use this switch because it delays error
- messages about undefined symbols until the link stage. The cc65
- compiler (which is supposed to produce correct assembler code in all
- circumstances, something which is not true for most assembler
- programmers) will insert this command to avoid importing each and every
- routine from the runtime library.
+Accessing symbols from other scopes is possible by using an explicit scope
+specification, provided that the scope where the symbol lives in has a name.
+The namespace token (<tt/::/) is used to access other scopes:
- Example:
+<tscreen><verb>
+ .scope foo
+ bar: .word 0
+ .endscope
- <tscreen><verb>
- .autoimport + ; Switch on auto import
- </verb></tscreen>
+ ...
+ lda foo::bar ; Access foo in scope bar
+</verb></tscreen>
+The only way to deny access to a scope from the outside is to declare a scope
+without a name (using the <tt/<ref id=".SCOPE" name=".SCOPE">/ command).
-<sect1><tt>.BLANK</tt><label id=".BLANK"><p>
+A special syntax is used to specify the global scope: If a symbol or scope is
+preceded by the namespace token, the global scope is searched:
- Builtin function. The function evaluates its argument in braces and
- yields "false" if the argument is non blank (there is an argument), and
- "true" if there is no argument. As an example, the <tt/.IFBLANK/ statement
- may be replaced by
+<tscreen><verb>
+ bar = 3
- <tscreen><verb>
- .if .blank(arg)
- </verb></tscreen>
+ .scope foo
+ bar = 2
+ lda #::bar ; Access the global bar (which is 3)
+ .endscope
+</verb></tscreen>
-<sect1>
<tt>.BSS</tt><label id=".BSS"><p>
+<sect1>
Scope search order<label id="scopesearch"><p>
- Switch to the BSS segment. The name of the BSS segment is always "BSS",
- so this is a shortcut for
+The assembler searches for a scope in a similar way as for a symbol. First, it
+looks in the current scope, and then it walks up the enclosing scopes until
+the scope is found.
- <tscreen><verb>
- .segment "BSS"
- </verb></tscreen>
+However, one important thing to note when using explicit scope syntax is, that
+a symbol may be accessed before it is defined, but a scope may <bf/not/ be
+used without a preceding definition. This means that in the following
+example:
- See also the <tt><ref id=".SEGMENT" name=".SEGMENT"></tt> command.
+<tscreen><verb>
+ .scope foo
+ bar = 3
+ .endscope
+
+ .scope outer
+ lda #foo::bar ; Will load 3, not 2!
+ .scope foo
+ bar = 2
+ .endscope
+ .endscope
+</verb></tscreen>
+the reference to the scope <tt/foo/ will use the global scope, and not the
+local one, because the local one is not visible at the point where it is
+referenced.
-<sect1><tt>.BYT, .BYTE</tt><label id=".BYTE"><p>
+Things get more complex if a complete chain of scopes is specified:
- Define byte sized data. Must be followed by a sequence of (byte ranged)
- expressions or strings.
+<tscreen><verb>
+ .scope foo
+ .scope outer
+ .scope inner
+ bar = 1
+ .endscope
+ .endscope
+ .scope another
+ .scope nested
+ lda #outer::inner::bar ; 1
+ .endscope
+ .endscope
+ .endscope
+
+ .scope outer
+ .scope inner
+ bar = 2
+ .endscope
+ .endscope
+</verb></tscreen>
- Example:
+When <tt/outer::inner::bar/ is referenced in the <tt/lda/ instruction, the
+assembler will first search in the local scope for a scope named <tt/outer/.
+Since none is found, the enclosing scope (<tt/another/) is checked. There is
+still no scope named <tt/outer/, so scope <tt/foo/ is checked, and finally
+scope <tt/outer/ is found. Within this scope, <tt/inner/ is searched, and in
+this scope, the assembler looks for a symbol named <tt/bar/.
+
+Please note that once the anchor scope is found, all following scopes
+(<tt/inner/ in this case) are expected to be found exactly in this scope. The
+assembler will search the scope tree only for the first scope (if it is not
+anchored in the root scope). Starting from there on, there is no flexibility,
+so if the scope named <tt/outer/ found by the assembler does not contain a
+scope named <tt/inner/, this would be an error, even if such a pair does exist
+(one level up in global scope).
+
+Ambiguities that may be introduced by this search algorithm may be removed by
+anchoring the scope specification in the global scope. In the example above,
+if you want to access the "other" symbol <tt/bar/, you would have to write:
- <tscreen><verb>
- .byte "Hello "
- .byt "world", $0D, $00
- </verb></tscreen>
+<tscreen><verb>
+ .scope foo
+ .scope outer
+ .scope inner
+ bar = 1
+ .endscope
+ .endscope
+ .scope another
+ .scope nested
+ lda #::outer::inner::bar ; 2
+ .endscope
+ .endscope
+ .endscope
+
+ .scope outer
+ .scope inner
+ bar = 2
+ .endscope
+ .endscope
+</verb></tscreen>
-<sect
1><tt>.CASE</tt><label id=".CASE"><p>
+<sect
>Address sizes and memory models<label id="address-sizes"><p>
- Switch on or off case sensitivity on identifiers. The default is off
- (that is, identifiers are case sensitive), but may be changed by the
- -i switch on the command line.
- The command must be followed by a '+' or '-' character to switch the
- option on or off respectively.
+<sect1>Address sizes<p>
- Example:
+ca65 assigns each segment and each symbol an address size. This is true, even
+if the symbol is not used as an address. You may also think of a value range
+of the symbol instead of an address size.
- <tscreen><verb>
- .case - ; Identifiers are not case sensitive
- </verb></tscreen>
+Possible address sizes are:
+<itemize>
+<item>Zeropage or direct (8 bits)
+<item>Absolute (16 bits)
+<item>Far (24 bits)
+<item>Long (32 bits)
+</itemize>
-<sect1><tt>.CHARMAP</tt><label id=".CHARMAP"><p>
+Since the assembler uses default address sizes for the segments and symbols,
+it is usually not necessary to override the default behaviour. In cases, where
+it is necessary, the following keywords may be used to specify address sizes:
- Apply a custom mapping for characters. The command is followed by two
- numbers in the range 1..255. The first one is the index of the source
- character, the second one is the mapping. The mapping applies to all
- character and string constants when they generate output, and overrides
- a mapping table specified with the <tt><ref id="option-t" name="-t"></tt>
- command line switch.
+<itemize>
+<item>DIRECT, ZEROPAGE or ZP for zeropage addressing (8 bits).
+<item>ABSOLUTE, ABS or NEAR for absolute addressing (16 bits).
+<item>FAR for far addressing (24 bits).
+<item>LONG or DWORD for long addressing (32 bits).
+</itemize>
- Example:
- <tscreen><verb>
- .charmap $41, $61 ; Map 'A' to 'a'
- </verb></tscreen>
+<sect1>Address sizes of segments<p>
+The assembler assigns an address size to each segment. Since the
+representation of a label within this segment is "segment start + offset",
+labels will inherit the address size of the segment they are declared in.
-<sect1><tt>.CODE</tt><label id=".CODE"><p>
+The address size of a segment may be changed, by using an optional address
+size modifier. See the <tt/<ref id=".SEGMENT" name="segment directive">/ for
+an explanation on how this is done.
- Switch to the CODE segment. The name of the CODE segment is always
- "CODE", so this is a shortcut for
- <tscreen><verb>
- .segment "CODE"
- </verb></tscreen>
+<sect1>Address sizes of symbols<p>
- See also the <tt><ref id=".SEGMENT" name=".SEGMENT"></tt> command.
-<sect1><tt>.CONDES</tt><label id=".CONDES"><p>
- Export a symbol and mark it in a special way. The linker is able to build
- tables of all such symbols. This may be used to automatically create a list
- of functions needed to initialize linked library modules.
+<sect1>Memory models<p>
- Note: The linker has a feature to build a table of marked routines, but it
- is your code that must call these routines, so just declaring a symbol with
- <tt/.CONDES/ does nothing by itself.
+The default address size of a segment depends on the memory model used. Since
+labels inherit the address size from the segment they are declared in,
+changing the memory model is an easy way to change the address size of many
+symbols at once.
- All symbols are exported as an absolute (16 bit) symbol. You don't need to
- use an additional <tt><ref id=".EXPORT" name=".EXPORT"></tt> statement, this
- is implied by <tt/.CONDES/.
- <tt/.CONDES/ is followed by the type, which may be <tt/constructor/,
- <tt/destructor/ or a numeric value between 0 and 6 (where 0 is the same as
- specifiying <tt/constructor/ and 1 is equal to specifying <tt/destructor/).
- The <tt><ref id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt> and <tt><ref
- id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> commands are actually shortcuts
- for <tt/.CONDES/ with a type of <tt/constructor/ resp. <tt/destructor/.
- After the type, an optional priority may be specified. If no priority is
- given, the default priority of 7 is used. Be careful when assigning
- priorities to your own module constructors so they won't interfere with the
- ones in the cc65 library.
+
+<sect>Pseudo variables<label id="pseudo-variables"><p>
+
+Pseudo variables are readable in all cases, and in some special cases also
+writable.
+
+<sect1><tt>*</tt><p>
+
+ Reading this pseudo variable will return the program counter at the start
+ of the current input line.
+
+ Assignment to this variable is possible when <tt/<ref id=".FEATURE"
+ name=".FEATURE pc_assignment">/ is used. Note: You should not use
+ assignments to <tt/*/, use <tt/<ref id=".ORG" name=".ORG">/ instead.
+
+
+<sect1><tt>.CPU</tt><label id=".CPU"><p>
+
+ Reading this pseudo variable will give a constant integer value that
+ tells which CPU is currently enabled. It can also tell which instruction
+ set the CPU is able to translate. The value read from the pseudo variable
+ should be further examined by using one of the constants defined by the
+ "cpu" macro package (see <tt/<ref id=".MACPACK" name=".MACPACK">/).
+
+ It may be used to replace the .IFPxx pseudo instructions or to construct
+ even more complex expressions.
Example:
<tscreen><verb>
- .condes ModuleInit, constructor
- .condes ModInit, 0, 16
+ .macpack cpu
+ .if (.cpu .bitand CPU_ISET_65816)
+ phx
+ phy
+ .else
+ txa
+ pha
+ tya
+ pha
+ .endif
</verb></tscreen>
- See the <tt><ref id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt> and <tt><ref
- id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> commands and the separate section
- <ref id="condes" name="Module constructors/destructors"> explaining the
- feature in more detail.
-
-<sect1><tt>.
CONCAT</tt><label id=".CONCAT"><p>
+<sect1><tt>.
PARAMCOUNT</tt><label id=".PARAMCOUNT"><p>
- Builtin function. The function allows to concatenate a list of string
- constants separated by commas. The result is a string constant that
- is the concatentation of all arguments. This function is most useful
- in macros and when used together with the <tt/.STRING/ builtin function.
- The function may be used in any case where a string constant is
- expected.
+ This builtin pseudo variable is only available in macros. It is replaced by
+ the actual number of parameters that were given in the macro invocation.
Example:
<tscreen><verb>
- .include .concat ("myheader", ".", "inc")
+ .macro foo arg1, arg2, arg3
+ .if .paramcount <> 3
+ .error "Too few parameters for macro foo"
+ .endif
+ ...
+ .endmacro
</verb></tscreen>
- This is the same as the command
+ See section <ref id="macros" name="Macros">.
+
+
+<sect1><tt>.TIME</tt><label id=".TIME"><p>
+
+ Reading this pseudo variable will give a constant integer value that
+ represents the current time in POSIX standard (as seconds since the
+ Epoch).
+
+ It may be used to encode the time of translation somewhere in the created
+ code.
+
+ Example:
<tscreen><verb>
- .include "myheader.inc"
+ .dword .time ; Place time here
</verb></tscreen>
-<sect1><tt>.
CONST</tt><label id=".CONST"><p>
+<sect1><tt>.
VERSION</tt><label id=".VERSION"><p>
- Builtin function. The function evaluates its argument in braces and
- yields "true" if the argument is a constant expression (that is, an
- expression that yields a constant value at assembly time) and "false"
- otherwise. As an example, the .IFCONST statement may be replaced by
+ Reading this pseudo variable will give the assembler version according to
+ the following formula:
+
+ VER_MAJOR*$100 + VER_MINOR*$10 + VER_PATCH
+
+ It may be used to encode the assembler version or check the assembler for
+ special features not available with older versions.
+
+ Example:
+
+ Version 2.11.1 of the assembler will return $2B1 as numerical constant when
+ reading the pseudo variable <tt/.VERSION/.
+
+
+
+<sect>Pseudo functions<label id="pseudo-functions"><p>
+
+Pseudo functions expect their arguments in parenthesis, and they have a result,
+either a string or an expression.
+
+
+<sect1><tt>.BANKBYTE</tt><label id=".BANKBYTE"><p>
+
+ The function returns the bank byte (that is, bits 16-23) of its argument.
+ It works identical to the '^' operator.
+
+ See: <tt><ref id=".HIBYTE" name=".HIBYTE"></tt>,
+ <tt><ref id=".LOBYTE" name=".LOBYTE"></tt>
+
+
+<sect1><tt>.BLANK</tt><label id=".BLANK"><p>
+
+ Builtin function. The function evaluates its argument in braces and yields
+ "false" if the argument is non blank (there is an argument), and "true" if
+ there is no argument. The token list that makes up the function argument
+ may optionally be enclosed in curly braces. This allows the inclusion of
+ tokens that would otherwise terminate the list (the closing right
+ parenthesis). The curly braces are not considered part of the list, a list
+ just consisting of curly braces is considered to be empty.
+
+ As an example, the <tt/.IFBLANK/ statement may be replaced by
+
+ <tscreen><verb>
+ .if .blank({arg})
+ </verb></tscreen>
+
+
+
+<sect1><tt>.CONCAT</tt><label id=".CONCAT"><p>
+
+ Builtin string function. The function allows to concatenate a list of string
+ constants separated by commas. The result is a string constant that is the
+ concatenation of all arguments. This function is most useful in macros and
+ when used together with the <tt/.STRING/ builtin function. The function may
+ be used in any case where a string constant is expected.
+
+ Example:
+
+ <tscreen><verb>
+ .include .concat ("myheader", ".", "inc")
+ </verb></tscreen>
+
+ This is the same as the command
+
+ <tscreen><verb>
+ .include "myheader.inc"
+ </verb></tscreen>
+
+
+<sect1><tt>.CONST</tt><label id=".CONST"><p>
+
+ Builtin function. The function evaluates its argument in braces and
+ yields "true" if the argument is a constant expression (that is, an
+ expression that yields a constant value at assembly time) and "false"
+ otherwise. As an example, the .IFCONST statement may be replaced by
<tscreen><verb>
.if .const(a + 3)
</verb></tscreen>
+<sect1><tt>.HIBYTE</tt><label id=".HIBYTE"><p>
+
+ The function returns the high byte (that is, bits 8-15) of its argument.
+ It works identical to the '>' operator.
+
+ See: <tt><ref id=".LOBYTE" name=".LOBYTE"></tt>,
+ <tt><ref id=".BANKBYTE" name=".BANKBYTE"></tt>
+
+
+<sect1><tt>.HIWORD</tt><label id=".HIWORD"><p>
+
+ The function returns the high word (that is, bits 16-31) of its argument.
+
+ See: <tt><ref id=".LOWORD" name=".LOWORD"></tt>
+
+
+<sect1><tt>.IDENT</tt><label id=".IDENT"><p>
+
+ The function expects a string as its argument, and converts this argument
+ into an identifier. If the string starts with the current <tt/<ref
+ id=".LOCALCHAR" name=".LOCALCHAR">/, it will be converted into a cheap local
+ identifier, otherwise it will be converted into a normal identifier.
+
+ Example:
+
+ <tscreen><verb>
+ .macro makelabel arg1, arg2
+ .ident (.concat (arg1, arg2)):
+ .endmacro
+
+ makelabel "foo", "bar"
+
+ .word foobar ; Valid label
+ </verb></tscreen>
+
+
+<sect1><tt>.LEFT</tt><label id=".LEFT"><p>
+
+ Builtin function. Extracts the left part of a given token list.
+
+ Syntax:
+
+ <tscreen><verb>
+ .LEFT (<int expr>, <token list>)
+ </verb></tscreen>
+
+ The first integer expression gives the number of tokens to extract from
+ the token list. The second argument is the token list itself. The token
+ list may optionally be enclosed into curly braces. This allows the
+ inclusion of tokens that would otherwise terminate the list (the closing
+ right paren in the given case).
+
+ Example:
+
+ To check in a macro if the given argument has a '#' as first token
+ (immediate addressing mode), use something like this:
+
+ <tscreen><verb>
+ .macro ldax arg
+ ...
+ .if (.match (.left (1, {arg}), #))
+
+ ; ldax called with immediate operand
+ ...
+
+ .endif
+ ...
+ .endmacro
+ </verb></tscreen>
+
+ See also the <tt><ref id=".MID" name=".MID"></tt> and <tt><ref id=".RIGHT"
+ name=".RIGHT"></tt> builtin functions.
+
+
+<sect1><tt>.LOBYTE</tt><label id=".LOBYTE"><p>
+
+ The function returns the low byte (that is, bits 0-7) of its argument.
+ It works identical to the '<' operator.
+
+ See: <tt><ref id=".HIBYTE" name=".HIBYTE"></tt>,
+ <tt><ref id=".BANKBYTE" name=".BANKBYTE"></tt>
+
+
+<sect1><tt>.LOWORD</tt><label id=".LOWORD"><p>
+
+ The function returns the low word (that is, bits 0-15) of its argument.
+
+ See: <tt><ref id=".HIWORD" name=".HIWORD"></tt>
+
+
+<sect1><tt>.MATCH</tt><label id=".MATCH"><p>
+
+ Builtin function. Matches two token lists against each other. This is
+ most useful within macros, since macros are not stored as strings, but
+ as lists of tokens.
+
+ The syntax is
+
+ <tscreen><verb>
+ .MATCH(<token list #1>, <token list #2>)
+ </verb></tscreen>
+
+ Both token list may contain arbitrary tokens with the exception of the
+ terminator token (comma resp. right parenthesis) and
+
+ <itemize>
+ <item>end-of-line
+ <item>end-of-file
+ </itemize>
+
+ The token lists may optionally be enclosed into curly braces. This allows
+ the inclusion of tokens that would otherwise terminate the list (the closing
+ right paren in the given case). Often a macro parameter is used for any of
+ the token lists.
+
+ Please note that the function does only compare tokens, not token
+ attributes. So any number is equal to any other number, regardless of the
+ actual value. The same is true for strings. If you need to compare tokens
+ <em/and/ token attributes, use the <tt><ref id=".XMATCH"
+ name=".XMATCH"></tt> function.
+
+ Example:
+
+ Assume the macro <tt/ASR/, that will shift right the accumulator by one,
+ while honoring the sign bit. The builtin processor instructions will allow
+ an optional "A" for accu addressing for instructions like <tt/ROL/ and
+ <tt/ROR/. We will use the <tt><ref id=".MATCH" name=".MATCH"></tt> function
+ to check for this and print and error for invalid calls.
+
+ <tscreen><verb>
+ .macro asr arg
+
+ .if (.not .blank(arg)) .and (.not .match ({arg}, a))
+ .error "Syntax error"
+ .endif
+
+ cmp #$80 ; Bit 7 into carry
+ lsr a ; Shift carry into bit 7
+
+ .endmacro
+ </verb></tscreen>
+
+ The macro will only accept no arguments, or one argument that must be the
+ reserved keyword "A".
+
+ See: <tt><ref id=".XMATCH" name=".XMATCH"></tt>
+
+
+<sect1><tt>.MID</tt><label id=".MID"><p>
+
+ Builtin function. Takes a starting index, a count and a token list as
+ arguments. Will return part of the token list.
+
+ Syntax:
+
+ <tscreen><verb>
+ .MID (<int expr>, <int expr>, <token list>)
+ </verb></tscreen>
+
+ The first integer expression gives the starting token in the list (the first
+ token has index 0). The second integer expression gives the number of tokens
+ to extract from the token list. The third argument is the token list itself.
+ The token list may optionally be enclosed into curly braces. This allows the
+ inclusion of tokens that would otherwise terminate the list (the closing
+ right paren in the given case).
+
+ Example:
+
+ To check in a macro if the given argument has a '<tt/#/' as first token
+ (immediate addressing mode), use something like this:
+
+ <tscreen><verb>
+ .macro ldax arg
+ ...
+ .if (.match (.mid (0, 1, {arg}), #))
+
+ ; ldax called with immediate operand
+ ...
+
+ .endif
+ ...
+ .endmacro
+ </verb></tscreen>
+
+ See also the <tt><ref id=".LEFT" name=".LEFT"></tt> and <tt><ref id=".RIGHT"
+ name=".RIGHT"></tt> builtin functions.
+
+
+<sect1><tt>.REF, .REFERENCED</tt><label id=".REFERENCED"><p>
+
+ Builtin function. The function expects an identifier as argument in braces.
+ The argument is evaluated, and the function yields "true" if the identifier
+ is a symbol that has already been referenced somewhere in the source file up
+ to the current position. Otherwise the function yields false. As an example,
+ the <tt><ref id=".IFREF" name=".IFREF"></tt> statement may be replaced by
+
+ <tscreen><verb>
+ .if .referenced(a)
+ </verb></tscreen>
+
+ See: <tt><ref id=".DEFINED" name=".DEFINED"></tt>
+
+
+<sect1><tt>.RIGHT</tt><label id=".RIGHT"><p>
+
+ Builtin function. Extracts the right part of a given token list.
+
+ Syntax:
+
+ <tscreen><verb>
+ .RIGHT (<int expr>, <token list>)
+ </verb></tscreen>
+
+ The first integer expression gives the number of tokens to extract from the
+ token list. The second argument is the token list itself. The token list
+ may optionally be enclosed into curly braces. This allows the inclusion of
+ tokens that would otherwise terminate the list (the closing right paren in
+ the given case).
+
+ See also the <tt><ref id=".LEFT" name=".LEFT"></tt> and <tt><ref id=".MID"
+ name=".MID"></tt> builtin functions.
+
+
+<sect1><tt>.SIZEOF</tt><label id=".SIZEOF"><p>
+
+ <tt/.SIZEOF/ is a pseudo function that returns the size of its argument. The
+ argument can be a struct/union, a struct member, a procedure, or a label. In
+ case of a procedure or label, its size is defined by the amount of data
+ placed in the segment where the label is relative to. If a line of code
+ switches segments (for example in a macro) data placed in other segments
+ does not count for the size.
+
+ Please note that a symbol or scope must exist, before it is used together with
+ <tt/.SIZEOF/ (this may get relaxed later, but will always be true for scopes).
+ A scope has preference over a symbol with the same name, so if the last part
+ of a name represents both, a scope and a symbol, the scope is chosen over the
+ symbol.
+
+ After the following code:
+
+ <tscreen><verb>
+ .struct Point ; Struct size = 4
+ xcoord .word
+ xcoord .word
+ .endstruct
+
+ P: .tag Point ; Declare a point
+ @P: .tag Point ; Declare another point
+
+ .code
+ .proc Code
+ nop
+ .proc Inner
+ nop
+ .endproc
+ nop
+ .endproc
+
+ .proc Data
+ .data ; Segment switch!!!
+ .res 4
+ .endproc
+ </verb></tscreen>
+
+ <descrip>
+ <tag><tt/.sizeof(Point)/</tag>
+ will have the value 4, because this is the size of struct <tt/Point/.
+
+ <tag><tt/.sizeof(Point::xcoord)/</tag>
+ will have the value 2, because this is the size of the member <tt/xcoord/
+ in struct <tt/Point/.
+
+ <tag><tt/.sizeof(P)/</tag>
+ will have the value 4, this is the size of the data declared on the same
+ source line as the label <tt/P/, which is in the same segment that <tt/P/
+ is relative to.
+
+ <tag><tt/.sizeof(@P)/</tag>
+ will have the value 4, see above. The example demonstrates that <tt/.SIZEOF/
+ does also work for cheap local symbols.
+
+ <tag><tt/.sizeof(Code)/</tag>
+ will have the value 3, since this is amount of data emitted into the code
+ segment, the segment that was active when <tt/Code/ was entered. Note that
+ this value includes the amount of data emitted in child scopes (in this
+ case <tt/Code::Inner/).
+
+ <tag><tt/.sizeof(Code::Inner)/</tag>
+ will have the value 1 as expected.
+
+ <tag><tt/.sizeof(Data)/</tag>
+ will have the value 0. Data is emitted within the scope <tt/Data/, but since
+ the segment is switched after entry, this data is emitted into another
+ segment.
+ </descrip>
+
+
+<sect1><tt>.STRAT</tt><label id=".STRAT"><p>
+
+ Builtin function. The function accepts a string and an index as
+ arguments and returns the value of the character at the given position
+ as an integer value. The index is zero based.
+
+ Example:
+
+ <tscreen><verb>
+ .macro M Arg
+ ; Check if the argument string starts with '#'
+ .if (.strat (Arg, 0) = '#')
+ ...
+ .endif
+ .endmacro
+ </verb></tscreen>
+
+
+<sect1><tt>.SPRINTF</tt><label id=".SPRINTF"><p>
+
+ Builtin function. It expects a format string as first argument. The number
+ and type of the following arguments depend on the format string. The format
+ string is similar to the one of the C <tt/printf/ function. Missing things
+ are: Length modifiers, variable width.
+
+ The result of the function is a string.
+
+ Example:
+
+ <tscreen><verb>
+ num = 3
+
+ ; Generate an identifier:
+ .ident (.sprintf ("%s%03d", "label", num)):
+ </verb></tscreen>
+
+
+<sect1><tt>.STRING</tt><label id=".STRING"><p>
+
+ Builtin function. The function accepts an argument in braces and converts
+ this argument into a string constant. The argument may be an identifier, or
+ a constant numeric value.
+
+ Since you can use a string in the first place, the use of the function may
+ not be obvious. However, it is useful in macros, or more complex setups.
+
+ Example:
+
+ <tscreen><verb>
+ ; Emulate other assemblers:
+ .macro section name
+ .segment .string(name)
+ .endmacro
+ </verb></tscreen>
+
+
+<sect1><tt>.STRLEN</tt><label id=".STRLEN"><p>
+
+ Builtin function. The function accepts a string argument in braces and
+ evaluates to the length of the string.
+
+ Example:
+
+ The following macro encodes a string as a pascal style string with
+ a leading length byte.
+
+ <tscreen><verb>
+ .macro PString Arg
+ .byte .strlen(Arg), Arg
+ .endmacro
+ </verb></tscreen>
+
+
+<sect1><tt>.TCOUNT</tt><label id=".TCOUNT"><p>
+
+ Builtin function. The function accepts a token list in braces. The function
+ result is the number of tokens given as argument. The token list may
+ optionally be enclosed into curly braces which are not considered part of
+ the list and not counted. Enclosement in curly braces allows the inclusion
+ of tokens that would otherwise terminate the list (the closing right paren
+ in the given case).
+
+ Example:
+
+ The <tt/ldax/ macro accepts the '#' token to denote immediate addressing (as
+ with the normal 6502 instructions). To translate it into two separate 8 bit
+ load instructions, the '#' token has to get stripped from the argument:
+
+ <tscreen><verb>
+ .macro ldax arg
+ .if (.match (.mid (0, 1, {arg}), #))
+ ; ldax called with immediate operand
+ lda #<(.right (.tcount ({arg})-1, {arg}))
+ ldx #>(.right (.tcount ({arg})-1, {arg}))
+ .else
+ ...
+ .endif
+ .endmacro
+ </verb></tscreen>
+
+
+<sect1><tt>.XMATCH</tt><label id=".XMATCH"><p>
+
+ Builtin function. Matches two token lists against each other. This is
+ most useful within macros, since macros are not stored as strings, but
+ as lists of tokens.
+
+ The syntax is
+
+ <tscreen><verb>
+ .XMATCH(<token list #1>, <token list #2>)
+ </verb></tscreen>
+
+ Both token list may contain arbitrary tokens with the exception of the
+ terminator token (comma resp. right parenthesis) and
+
+ <itemize>
+ <item>end-of-line
+ <item>end-of-file
+ </itemize>
+
+ The token lists may optionally be enclosed into curly braces. This allows
+ the inclusion of tokens that would otherwise terminate the list (the closing
+ right paren in the given case). Often a macro parameter is used for any of
+ the token lists.
+
+ The function compares tokens <em/and/ token values. If you need a function
+ that just compares the type of tokens, have a look at the <tt><ref
+ id=".MATCH" name=".MATCH"></tt> function.
+
+ See: <tt><ref id=".MATCH" name=".MATCH"></tt>
+
+
+
+<sect>Control commands<label id="control-commands"><p>
+
+Here's a list of all control commands and a description, what they do:
+
+
+<sect1><tt>.A16</tt><label id=".A16"><p>
+
+ Valid only in 65816 mode. Switch the accumulator to 16 bit.
+
+ Note: This command will not emit any code, it will tell the assembler to
+ create 16 bit operands for immediate accumulator addressing mode.
+
+ See also: <tt><ref id=".SMART" name=".SMART"></tt>
+
+
+<sect1><tt>.A8</tt><label id=".A8"><p>
+
+ Valid only in 65816 mode. Switch the accumulator to 8 bit.
+
+ Note: This command will not emit any code, it will tell the assembler to
+ create 8 bit operands for immediate accu addressing mode.
+
+ See also: <tt><ref id=".SMART" name=".SMART"></tt>
+
+
+<sect1><tt>.ADDR</tt><label id=".ADDR"><p>
+
+ Define word sized data. In 6502 mode, this is an alias for <tt/.WORD/ and
+ may be used for better readability if the data words are address values. In
+ 65816 mode, the address is forced to be 16 bit wide to fit into the current
+ segment. See also <tt><ref id=".FARADDR" name=".FARADDR"></tt>. The command
+ must be followed by a sequence of (not necessarily constant) expressions.
+
+ Example:
+
+ <tscreen><verb>
+ .addr $0D00, $AF13, _Clear
+ </verb></tscreen>
+
+ See: <tt><ref id=".FARADDR" name=".FARADDR"></tt>, <tt><ref id=".WORD"
+ name=".WORD"></tt>
+
+
+<sect1><tt>.ALIGN</tt><label id=".ALIGN"><p>
+
+ Align data to a given boundary. The command expects a constant integer
+ argument that must be a power of two, plus an optional second argument
+ in byte range. If there is a second argument, it is used as fill value,
+ otherwise the value defined in the linker configuration file is used
+ (the default for this value is zero).
+
+ Since alignment depends on the base address of the module, you must
+ give the same (or a greater) alignment for the segment when linking.
+ The linker will give you a warning, if you don't do that.
+
+ Example:
+
+ <tscreen><verb>
+ .align 256
+ </verb></tscreen>
+
+
+<sect1><tt>.ASCIIZ</tt><label id=".ASCIIZ"><p>
+
+ Define a string with a trailing zero.
+
+ Example:
+
+ <tscreen><verb>
+ Msg: .asciiz "Hello world"
+ </verb></tscreen>
+
+ This will put the string "Hello world" followed by a binary zero into
+ the current segment. There may be more strings separated by commas, but
+ the binary zero is only appended once (after the last one).
+
+
+<sect1><tt>.ASSERT</tt><label id=".ASSERT"><p>
+
+ Add an assertion. The command is followed by an expression, an action
+ specifier, and an optional message that is output in case the assertion
+ fails. If no message was given, the string "Assertion failed" is used. The
+ action specifier may be one of <tt/warning/ or <tt/error/. The assertion is
+ evaluated by the assembler if possible, and also passed to the linker in the
+ object file (if one is generated). The linker will then evaluate the
+ expression when segment placement has been done.
+
+ Example:
+
+ <tscreen><verb>
+ .assert * = $8000, error, "Code not at $8000"
+ </verb></tscreen>
+
+ The example assertion will check that the current location is at $8000,
+ when the output file is written, and abort with an error if this is not
+ the case. More complex expressions are possible. The action specifier
+ <tt/warning/ outputs a warning, while the <tt/error/ specifier outputs
+ an error message. In the latter case, generation if the output file is
+ suppressed in both the assembler and linker.
+
+
+<sect1><tt>.AUTOIMPORT</tt><label id=".AUTOIMPORT"><p>
+
+ Is followed by a plus or a minus character. When switched on (using a
+ +), undefined symbols are automatically marked as import instead of
+ giving errors. When switched off (which is the default so this does not
+ make much sense), this does not happen and an error message is
+ displayed. The state of the autoimport flag is evaluated when the
+ complete source was translated, before outputting actual code, so it is
+ <em/not/ possible to switch this feature on or off for separate sections
+ of code. The last setting is used for all symbols.
+
+ You should probably not use this switch because it delays error
+ messages about undefined symbols until the link stage. The cc65
+ compiler (which is supposed to produce correct assembler code in all
+ circumstances, something which is not true for most assembler
+ programmers) will insert this command to avoid importing each and every
+ routine from the runtime library.
+
+ Example:
+
+ <tscreen><verb>
+ .autoimport + ; Switch on auto import
+ </verb></tscreen>
+
+
+<sect1><tt>.BSS</tt><label id=".BSS"><p>
+
+ Switch to the BSS segment. The name of the BSS segment is always "BSS",
+ so this is a shortcut for
+
+ <tscreen><verb>
+ .segment "BSS"
+ </verb></tscreen>
+
+ See also the <tt><ref id=".SEGMENT" name=".SEGMENT"></tt> command.
+
+
+<sect1><tt>.BYT, .BYTE</tt><label id=".BYTE"><p>
+
+ Define byte sized data. Must be followed by a sequence of (byte ranged)
+ expressions or strings.
+
+ Example:
+
+ <tscreen><verb>
+ .byte "Hello "
+ .byt "world", $0D, $00
+ </verb></tscreen>
+
+
+<sect1><tt>.CASE</tt><label id=".CASE"><p>
+
+ Switch on or off case sensitivity on identifiers. The default is off
+ (that is, identifiers are case sensitive), but may be changed by the
+ -i switch on the command line.
+ The command must be followed by a '+' or '-' character to switch the
+ option on or off respectively.
+
+ Example:
+
+ <tscreen><verb>
+ .case - ; Identifiers are not case sensitive
+ </verb></tscreen>
+
+
+<sect1><tt>.CHARMAP</tt><label id=".CHARMAP"><p>
+
+ Apply a custom mapping for characters. The command is followed by two
+ numbers in the range 1..255. The first one is the index of the source
+ character, the second one is the mapping. The mapping applies to all
+ character and string constants when they generate output, and overrides
+ a mapping table specified with the <tt><ref id="option-t" name="-t"></tt>
+ command line switch.
+
+ Example:
+
+ <tscreen><verb>
+ .charmap $41, $61 ; Map 'A' to 'a'
+ </verb></tscreen>
+
+
+<sect1><tt>.CODE</tt><label id=".CODE"><p>
+
+ Switch to the CODE segment. The name of the CODE segment is always
+ "CODE", so this is a shortcut for
+
+ <tscreen><verb>
+ .segment "CODE"
+ </verb></tscreen>
+
+ See also the <tt><ref id=".SEGMENT" name=".SEGMENT"></tt> command.
+
+
+<sect1><tt>.CONDES</tt><label id=".CONDES"><p>
+
+ Export a symbol and mark it in a special way. The linker is able to build
+ tables of all such symbols. This may be used to automatically create a list
+ of functions needed to initialize linked library modules.
+
+ Note: The linker has a feature to build a table of marked routines, but it
+ is your code that must call these routines, so just declaring a symbol with
+ <tt/.CONDES/ does nothing by itself.
+
+ All symbols are exported as an absolute (16 bit) symbol. You don't need to
+ use an additional <tt><ref id=".EXPORT" name=".EXPORT"></tt> statement, this
+ is implied by <tt/.CONDES/.
+
+ <tt/.CONDES/ is followed by the type, which may be <tt/constructor/,
+ <tt/destructor/ or a numeric value between 0 and 6 (where 0 is the same as
+ specifying <tt/constructor/ and 1 is equal to specifying <tt/destructor/).
+ The <tt><ref id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt>, <tt><ref
+ id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> and <tt><ref id=".INTERRUPTOR"
+ name=".INTERRUPTOR"></tt> commands are actually shortcuts for <tt/.CONDES/
+ with a type of <tt/constructor/ resp. <tt/destructor/ or <tt/interruptor/.
+
+ After the type, an optional priority may be specified. Higher numeric values
+ mean higher priority. If no priority is given, the default priority of 7 is
+ used. Be careful when assigning priorities to your own module constructors
+ so they won't interfere with the ones in the cc65 library.
+
+ Example:
+
+ <tscreen><verb>
+ .condes ModuleInit, constructor
+ .condes ModInit, 0, 16
+ </verb></tscreen>
+
+ See the <tt><ref id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt>, <tt><ref
+ id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> and <tt><ref id=".INTERRUPTOR"
+ name=".INTERRUPTOR"></tt> commands and the separate section <ref id="condes"
+ name="Module constructors/destructors"> explaining the feature in more
+ detail.
+
+
<sect1><tt>.CONSTRUCTOR</tt><label id=".CONSTRUCTOR"><p>
Export a symbol and mark it as a module constructor. This may be used
A constructor is always exported as an absolute (16 bit) symbol. You don't
need to use an additional <tt/.export/ statement, this is implied by
<tt/.constructor/. It may have an optional priority that is separated by a
- comma. If no priority is given, the default priority of 7 is used. Be
- careful when assigning priorities to your own module constructors so they
- won't interfere with the ones in the cc65 library.
+ comma. Higher numeric values mean a higher priority. If no priority is
+ given, the default priority of 7 is used. Be careful when assigning
+ priorities to your own module constructors so they won't interfere with the
+ ones in the cc65 library.
Example:
feature in more detail.
-<sect1><tt>.CPU</tt><label id=".CPU"><p>
-
- Reading this pseudo variable will give a constant integer value that
- tells which instruction set is currently enabled. Possible values are:
-
- <tscreen><verb>
- 0 --> 6502
- 1 --> 65SC02
- 2 --> 65SC816
- 3 --> SunPlus SPC
- </verb></tscreen>
-
- It may be used to replace the .IFPxx pseudo instructions or to construct
- even more complex expressions.
-
- Example:
-
- <tscreen><verb>
- .if (.cpu = 0) .or (.cpu = 1)
- txa
- pha
- tya
- pha
- .else
- phx
- phy
- .endif
- </verb></tscreen>
-
-
<sect1><tt>.DATA</tt><label id=".DATA"><p>
Switch to the DATA segment. The name of the DATA segment is always
A destructor is always exported as an absolute (16 bit) symbol. You don't
need to use an additional <tt/.export/ statement, this is implied by
<tt/.destructor/. It may have an optional priority that is separated by a
- comma. If no priority is given, the default priority of 7 is used. Be
- careful when assigning priorities to your own module destructors so they
- won't interfere with the ones in the cc65 library.
+ comma. Higher numerical values mean a higher priority. If no priority is
+ given, the default priority of 7 is used. Be careful when assigning
+ priorities to your own module destructors so they won't interfere with the
+ ones in the cc65 library.
Example:
is read from an include file.
+<sect1><tt>.ENDENUM</tt><label id=".ENDENUM"><p>
+
+ End a <tt><ref id=".ENUM" name=".ENUM"></tt> declaration.
+
+
<sect1><tt>.ENDIF</tt><label id=".ENDIF"><p>
Conditional assembly: Close a <tt><ref id=".IF" name=".IF..."></tt> or
End a <tt><ref id=".REPEAT" name=".REPEAT"></tt> block.
+<sect1><tt>.ENDSCOPE</tt><label id=".ENDSCOPE"><p>
+
+ End of local lexical level (see <tt/<ref id=".SCOPE" name=".SCOPE">/).
+
+
+<sect1><tt>.ENDSTRUCT</tt><label id=".ENDSTRUCT"><p>
+
+ Ends a struct definition. See the <tt/<ref id=".STRUCT" name=".STRUCT">/
+ command and the separate section named <ref id="structs" name=""Structs
+ and unions"">.
+
+
+<sect1><tt>.ENUM</tt><label id=".ENUM"><p>
+
+ Start an enumeration. This directive is very similar to the C <tt/enum/
+ keyword. If a name is given, a new scope is created for the enumeration,
+ otherwise the enumeration members are placed in the enclosing scope.
+
+ In the enumeration body, symbols are declared. The first symbol has a value
+ of zero, and each following symbol will get the value of the preceding plus
+ one. This behaviour may be overridden by an explicit assignment. Two symbols
+ may have the same value.
+
+ Example:
+
+ <tscreen><verb>
+ .enum errorcodes
+ no_error
+ file_error
+ parse_error
+ .endenum
+ </verb></tscreen>
+
+ Above example will create a new scope named <tt/errorcodes/ with three
+ symbols in it that get the values 0, 1 and 2 respectively. Another way
+ to write this would have been:
+
+ <tscreen><verb>
+ .scope errorcodes
+ no_error = 0
+ file_error = 1
+ parse_error = 2
+ .endscope
+ </verb></tscreen>
+
+ Please note that explicit scoping must be used to access the identifiers:
+
+ <tscreen><verb>
+ .word errorcodes::no_error
+ </verb></tscreen>
+
+ A more complex example:
+
+ <tscreen><verb>
+ .enum
+ EUNKNOWN = -1
+ EOK
+ EFILE
+ EBUSY
+ EAGAIN
+ EWOULDBLOCK = EAGAIN
+ .endenum
+ </verb></tscreen>
+
+ In this example, the enumeration does not have a name, which means that the
+ members will be visible in the enclosing scope and can be used in this scope
+ without explicit scoping. The first member (<tt/EUNKNOWN/) has the value -1.
+ The value for the following members is incremented by one, so <tt/EOK/ would
+ be zero and so on. <tt/EWOULDBLOCK/ is an alias for <tt/EGAIN/, so it has an
+ override for the value using an already defined symbol.
+
+
<sect1><tt>.ERROR</tt><label id=".ERROR"><p>
Force an assembly error. The assembler will output an error message
- preceeded by "User error" and will <em/not/ produce an object file.
+ preceded by "User error" and will <em/not/ produce an object file.
This command may be used to check for initial conditions that must be
set before assembling a source file.
<sect1><tt>.EXITMAC, .EXITMACRO</tt><label id=".EXITMACRO"><p>
- Abort a macro expansion immidiately. This command is often useful in
+ Abort a macro expansion immediately. This command is often useful in
recursive macros. See separate section <ref id="macros" name="Macros">.
<sect1><tt>.EXPORT</tt><label id=".EXPORT"><p>
Make symbols accessible from other modules. Must be followed by a comma
- separated list of symbols to export.
+ separated list of symbols to export, with each one optionally followed by
+ an address specification. The default is to export the symbol with the
+ address size it actually has. The assembler will issue a warning, if the
+ symbol is exported with an address size smaller than the actual address
+ size.
Example:
<tscreen><verb>
- .export foo, bar
+ .export foo
+ .export bar: far
</verb></tscreen>
See: <tt><ref id=".EXPORTZP" name=".EXPORTZP"></tt>
Make symbols accessible from other modules. Must be followed by a comma
separated list of symbols to export. The exported symbols are explicitly
- marked as zero page symols.
+ marked as zero page symbols.
Example:
<descrip>
+ <tag><tt>at_in_identifiers</tt></tag>
+
+ Accept the at character (`@') as a valid character in identifiers. The
+ at character is not allowed to start an identifier, even with this
+ feature enabled.
+
+ <tag><tt>dollar_in_identifiers</tt></tag>
+
+ Accept the dollar sign (`$') as a valid character in identifiers. The
+ at character is not allowed to start an identifier, even with this
+ feature enabled.
+
<tag><tt>dollar_is_pc</tt></tag>
The dollar sign may be used as an alias for the star (`*'), which
Allow labels without a trailing colon. These labels are only accepted,
if they start at the beginning of a line (no leading white space).
- <tag><tt>loose_string_term</tt></tag>
+ <tag><tt>leading_dot_in_identifiers</tt></tag>
- Accept single quotes as well as double quotes as terminators for string
- constants.
+ Accept the dot (`.') as the first character of an identifier. This may be
+ used for example to create macro names that start with a dot emulating
+ control directives of other assemblers. Note however, that none of the
+ reserved keywords built into the assembler, that starts with a dot, may be
+ overridden. When using this feature, you may also get into trouble if
+ later versions of the assembler define new keywords starting with a dot.
<tag><tt>loose_char_term</tt></tag>
Accept single quotes as well as double quotes as terminators for char
constants.
- <tag><tt>at_in_identifiers</tt></tag>
+ <tag><tt>loose_string_term</tt></tag>
- Accept the at character (`@') as a valid character in identifiers. The
- at character is not allowed to start an identifier, even with this
- feature enabled.
+ Accept single quotes as well as double quotes as terminators for string
+ constants.
- <tag><tt>dollar_in_identifiers</tt></tag>
+ <tag><tt>missing_char_term</tt></tag>
- Accept the dollar sign (`$') as a valid character in identifiers. The
- at character is not allowed to start an identifier, even with this
- feature enabled.
+ Accept single quoted character constants where the terminating quote is
+ missing.
+ <tscreen><verb>
+ lda #'a
+ </verb></tscreen>
+ <bf/Note:/ This does not work in conjunction with <tt/.FEATURE
+ loose_string_term/, since in this case the input would be ambiguous.
- <tag><tt>leading_dot_in_identifiers</tt></tag>
+ <tag><tt>org_per_seg</tt><label id="org_per_seg"></tag>
- Accept the dot (`.') as the first character of an identifier. This may be
- used for example to create macro names that start with a dot emulating
- control directives of other assemblers. Note however, that none of the
- reserved keywords built into the assembler, that starts with a dot, may be
- overridden. When using this feature, you may also get into trouble if
- later versions of the assembler define new keywords starting with a dot.
+ This feature makes relocatable/absolute mode local to the current segment.
+ Using <tt><ref id=".ORG" name=".ORG"></tt> when <tt/org_per_seg/ is in
+ effect will only enable absolute mode for the current segment. Dito for
+ <tt><ref id=".RELOC" name=".RELOC"></tt>.
<tag><tt>pc_assignment</tt></tag>
removing the lines with the assignments may also be an option when porting
code written for older assemblers).
+ <tag><tt>ubiquitous_idents</tt></tag>
+
+ Allow the use of instructions names as names for macros and symbols. This
+ makes it possible to "overload" instructions by defining a macro with the
+ same name. This does also make it possible to introduce hard to find errors
+ in your code, so be careful!
+
</descrip>
It is also possible to specify features on the command line using the
source, are exported, all others are imported. Additional <tt><ref
id=".IMPORTZP" name=".IMPORTZP"></tt> or <tt><ref id=".EXPORTZP"
name=".EXPORTZP"></tt> commands for the same symbol are allowed. The symbols
- in the list are explicitly marked as zero page symols.
+ in the list are explicitly marked as zero page symbols.
Example:
<sect1><tt>.IF</tt><label id=".IF"><p>
- Conditional assembly: Evalute an expression and switch assembler output
+ Conditional assembly: Evaluate an expression and switch assembler output
on or off depending on the expression. The expression must be a constant
expression, that is, all operands must be defined.
(see <tt><ref id=".PC02" name=".PC02"></tt> command).
+<sect1><tt>.IFPSC02</tt><label id=".IFPSC02"><p>
+
+ Conditional assembly: Check if the assembler is currently in 65SC02 mode
+ (see <tt><ref id=".PSC02" name=".PSC02"></tt> command).
+
+
<sect1><tt>.IFREF</tt><label id=".IFREF"><p>
Conditional assembly: Check if a symbol is referenced. Must be followed
<sect1><tt>.IMPORT</tt><label id=".IMPORT"><p>
Import a symbol from another module. The command is followed by a comma
- separated list of symbols to import.
+ separated list of symbols to import, with each one optionally followed by
+ an address specification.
Example:
<tscreen><verb>
- .import foo, bar
+ .import foo
+ .import bar: zeropage
</verb></tscreen>
See: <tt><ref id=".IMPORTZP" name=".IMPORTZP"></tt>
In addition to that, a start offset and a size value may be specified,
separated by commas. If no size is specified, all of the file from the
start offset to end-of-file is used. If no start position is specified
- either, zero is assume (which means that the whole file is inserted).
+ either, zero is assumed (which means that the whole file is inserted).
Example:
</verb></tscreen>
-<sect1><tt>.LEFT</tt><label id=".LEFT"><p>
-
- Builtin function. Extracts the left part of a given token list.
+<sect1><tt>.INTERRUPTOR</tt><label id=".INTERRUPTOR"><p>
- Syntax:
+ Export a symbol and mark it as an interruptor. This may be used together
+ with the linker to build a table of interruptor subroutines that are called
+ in an interrupt.
- <tscreen><verb>
- .LEFT (<int expr>, <token list>)
- </verb></tscreen>
+ Note: The linker has a feature to build a table of marked routines, but it
+ is your code that must call these routines, so just declaring a symbol as
+ interruptor does nothing by itself.
- The first integer expression gives the number of tokens to extract from
- the token list. The second argument is the token list itself.
+ An interruptor is always exported as an absolute (16 bit) symbol. You don't
+ need to use an additional <tt/.export/ statement, this is implied by
+ <tt/.interruptor/. It may have an optional priority that is separated by a
+ comma. Higher numeric values mean a higher priority. If no priority is
+ given, the default priority of 7 is used. Be careful when assigning
+ priorities to your own module constructors so they won't interfere with the
+ ones in the cc65 library.
Example:
- To check in a macro if the given argument has a '#' as first token
- (immidiate addressing mode), use something like this:
-
<tscreen><verb>
- .macro ldax arg
- ...
- .if (.match (.left (1, arg), #))
-
- ; ldax called with immidiate operand
- ...
-
- .endif
- ...
- .endmacro
+ .interruptor IrqHandler
+ .interruptor Handler, 16
</verb></tscreen>
- See also the <tt><ref id=".MID" name=".MID"></tt> and <tt><ref id=".RIGHT"
- name=".RIGHT"></tt> builtin functions.
+ See the <tt><ref id=".CONDES" name=".CONDES"></tt> command and the separate
+ section <ref id="condes" name="Module constructors/destructors"> explaining
+ the feature in more detail.
<sect1><tt>.LINECONT</tt><label id=".LINECONT"><p>
packages are:
<tscreen><verb>
+ atari Defines the scrcode macro.
+ cbm Defines the scrcode macro.
+ cpu Defines constants for the .CPU variable.
generic Defines generic macros like add and sub.
longbranch Defines conditional long jump macros.
</verb></tscreen>
See section <ref id="macros" name="Macros">.
-<sect1><tt>.MATCH</tt><label id=".MATCH"><p>
-
- Builtin function. Matches two token lists against each other. This is
- most useful within macros, since macros are not stored as strings, but
- as lists of tokens.
-
- The syntax is
-
- <tscreen><verb>
- .MATCH(<token list #1>, <token list #2>)
- </verb></tscreen>
-
- Both token list may contain arbitrary tokens with the exception of the
- terminator token (comma resp. right parenthesis) and
-
- <itemize>
- <item>end-of-line
- <item>end-of-file
- </itemize>
-
- Often a macro parameter is used for any of the token lists.
-
- Please note that the function does only compare tokens, not token
- attributes. So any number is equal to any other number, regardless of the
- actual value. The same is true for strings. If you need to compare tokens
- <em/and/ token attributes, use the <tt><ref id=".XMATCH"
- name=".XMATCH"></tt> function.
-
- Example:
-
- Assume the macro <tt/ASR/, that will shift right the accumulator by one,
- while honoring the sign bit. The builtin processor instructions will allow
- an optional "A" for accu addressing for instructions like <tt/ROL/ and
- <tt/ROR/. We will use the <tt><ref id=".MATCH" name=".MATCH"></tt> function
- to check for this and print and error for invalid calls.
-
- <tscreen><verb>
- .macro asr arg
-
- .if (.not .blank(arg)) .and (.not .match (arg, a))
- .error "Syntax error"
- .endif
-
- cmp #$80 ; Bit 7 into carry
- lsr a ; Shift carry into bit 7
-
- .endmacro
- </verb></tscreen>
-
- The macro will only accept no arguments, or one argument that must be the
- reserved keyword "A".
-
- See: <tt><ref id=".XMATCH" name=".XMATCH"></tt>
-
-
-<sect1><tt>.MID</tt><label id=".MID"><p>
-
- Builtin function. Takes a starting index, a count and a token list as
- arguments. Will return part of the token list.
-
- Syntax:
-
- <tscreen><verb>
- .MID (<int expr>, <int expr>, <token list>)
- </verb></tscreen>
-
- The first integer expression gives the starting token in the list (the
- first token has index 0). The second integer expression gives the number
- of tokens to extract from the token list. The third argument is the
- token list itself.
-
- Example:
-
- To check in a macro if the given argument has a '<tt/#/' as first token
- (immidiate addressing mode), use something like this:
-
- <tscreen><verb>
- .macro ldax arg
- ...
- .if (.match (.mid (0, 1, arg), #))
-
- ; ldax called with immidiate operand
- ...
-
- .endif
- ...
- .endmacro
- </verb></tscreen>
-
- See also the <tt><ref id=".LEFT" name=".LEFT"></tt> and <tt><ref id=".RIGHT"
- name=".RIGHT"></tt> builtin functions.
-
-
<sect1><tt>.ORG</tt><label id=".ORG"><p>
Start a section of absolute code. The command is followed by a constant
assembled. Use <tt><ref id=".RELOC" name=".RELOC"></tt> to switch back to
relocatable code.
- Please note that you <em/do not need/ this command in most cases. Placing
+ By default, absolute/relocatable mode is global (valid even when switching
+ segments). Using <tt>.FEATURE <ref id="org_per_seg" name="org_per_seg"></tt>
+ it can be made segment local.
+
+ Please note that you <em/do not need/ <tt/.ORG/ in most cases. Placing
code at a specific address is the job of the linker, not the assembler, so
there is usually no reason to assemble code to a specific address.
- You may not switch segments while inside a section of absolute code.
-
Example:
<tscreen><verb>
<sect1><tt>.OUT</tt><label id=".OUT"><p>
Output a string to the console without producing an error. This command
- is similiar to <tt/.ERROR/, however, it does not force an assembler error
+ is similar to <tt/.ERROR/, however, it does not force an assembler error
that prevents the creation of an object file.
Example:
<sect1><tt>.P02</tt><label id=".P02"><p>
- Enable the 6502 instruction set, disable 65C02 and 65816 instructions.
- This is the default if not overridden by the <tt/--cpu/ command line
- option.
+ Enable the 6502 instruction set, disable 65SC02, 65C02 and 65816
+ instructions. This is the default if not overridden by the
+ <tt><ref id="option--cpu" name="--cpu"></tt> command line option.
- See: <tt><ref id=".PC02" name=".PC02"></tt> and <tt><ref id=".P816"
- name=".P816"></tt>
+ See: <tt><ref id=".PC02" name=".PC02"></tt>, <tt><ref id=".PSC02"
+ name=".PSC02"></tt> and <tt><ref id=".P816" name=".P816"></tt>
<sect1><tt>.P816</tt><label id=".P816"><p>
- Enable the 65816 instruction set. This is a superset of the 65C02 and
+ Enable the 65816 instruction set. This is a superset of the 65SC02 and
6502 instruction sets.
- See: <tt><ref id=".P02" name=".P02"></tt> and <tt><ref id=".PC02"
- name=".PC02"></tt>
+ See: <tt><ref id=".P02" name=".P02"></tt>, <tt><ref id=".PSC02"
+ name=".PSC02"></tt> and <tt><ref id=".PC02" name=".PC02"></tt>
<sect1><tt>.PAGELEN, .PAGELENGTH</tt><label id=".PAGELENGTH"><p>
</verb></tscreen>
-<sect1><tt>.PARAMCOUNT</tt><label id=".PARAMCOUNT"><p>
-
- This builtin pseudo variable is only available in macros. It is replaced by
- the actual number of parameters that were given in the macro invocation.
-
- Example:
-
- <tscreen><verb>
- .macro foo arg1, arg2, arg3
- .if .paramcount <> 3
- .error "Too few parameters for macro foo"
- .endif
- ...
- .endmacro
- </verb></tscreen>
-
- See section <ref id="macros" name="Macros">.
-
-
<sect1><tt>.PC02</tt><label id=".PC02"><p>
Enable the 65C02 instructions set. This instruction set includes all
- 6502 instructions.
+ 6502 and 65SC02 instructions.
- See: <tt><ref id=".P02" name=".P02"></tt> and <tt><ref id=".P816"
- name=".P816"></tt>
+ See: <tt><ref id=".P02" name=".P02"></tt>, <tt><ref id=".PSC02"
+ name=".PSC02"></tt> and <tt><ref id=".P816" name=".P816"></tt>
<sect1><tt>.POPSEG</tt><label id=".POPSEG"><p>
<sect1><tt>.PROC</tt><label id=".PROC"><p>
- Start a nested lexical level. All new symbols from now on are in the local
- lexical level and are not accessible from outside. Symbols defined outside
- this local level may be accessed as long as their names are not used for new
- symbols inside the level. Symbols names in other lexical levels do not
- clash, so you may use the same names for identifiers. The lexical level ends
- when the <tt><ref id=".ENDPROC" name=".ENDPROC"></tt> command is read.
- Lexical levels may be nested up to a depth of 16.
-
- The command may be followed by an identifier, in this case the
- identifier is declared in the outer level as a label having the value of
- the program counter at the start of the lexical level.
+ Start a nested lexical level with the given name and adds a symbol with this
+ name to the enclosing scope. All new symbols from now on are in the local
+ lexical level and are accessible from outside only via <ref id="scopesyntax"
+ name="explicit scope specification">. Symbols defined outside this local
+ level may be accessed as long as their names are not used for new symbols
+ inside the level. Symbols names in other lexical levels do not clash, so you
+ may use the same names for identifiers. The lexical level ends when the
+ <tt><ref id=".ENDPROC" name=".ENDPROC"></tt> command is read. Lexical levels
+ may be nested up to a depth of 16 (this is an artificial limit to protect
+ against errors in the source).
Note: Macro names are always in the global level and in a separate name
space. There is no special reason for this, it's just that I've never
dey
bne L1 ; Reference local symbol
rts
- .endproc ; Leave lexical level
+ .endproc ; Leave lexical level
</verb></tscreen>
- See: <tt><ref id=".ENDPROC" name=".ENDPROC"></tt>
+ See: <tt/<ref id=".ENDPROC" name=".ENDPROC">/ and <tt/<ref id=".SCOPE"
+ name=".SCOPE">/
+
+
+<sect1><tt>.PSC02</tt><label id=".PSC02"><p>
+
+ Enable the 65SC02 instructions set. This instruction set includes all
+ 6502 instructions.
+
+ See: <tt><ref id=".P02" name=".P02"></tt>, <tt><ref id=".PC02"
+ name=".PC02"></tt> and <tt><ref id=".P816" name=".P816"></tt>
<sect1><tt>.PUSHSEG</tt><label id=".PUSHSEG"><p>
See: <tt><ref id=".POPSEG" name=".POPSEG"></tt>
-<sect1><tt>.REF, .REFERENCED</tt><label id=".REFERENCED"><p>
-
- Builtin function. The function expects an identifier as argument in braces.
- The argument is evaluated, and the function yields "true" if the identifier
- is a symbol that has already been referenced somewhere in the source file up
- to the current position. Otherwise the function yields false. As an example,
- the <tt><ref id=".IFREF" name=".IFREF"></tt> statement may be replaced by
-
- <tscreen><verb>
- .if .referenced(a)
- </verb></tscreen>
+<sect1><tt>.RELOC</tt><label id=".RELOC"><p>
- See: <tt><ref id=".DEFINED" name=".DEFINED"></tt>
+ Switch back to relocatable mode. See the <tt><ref id=".ORG"
+ name=".ORG"></tt> command.
<sect1><tt>.REPEAT</tt><label id=".REPEAT"><p>
<tscreen><verb>
.macro Crypt Arg
.repeat .strlen(Arg), I
- .byte .strat(Arg, I) .xor $55
+ .byte .strat(Arg, I) ^ $55
.endrep
.endmacro
</verb></tscreen>
See: <tt><ref id=".ENDREPEAT" name=".ENDREPEAT"></tt>
-<sect1><tt>.RELOC</tt><label id=".RELOC"><p>
-
- Switch back to relocatable mode. See the <tt><ref id=".ORG"
- name=".ORG"></tt> command.
-
-
<sect1><tt>.RES</tt><label id=".RES"><p>
Reserve storage. The command is followed by one or two constant
<tscreen><verb>
; Reserve 12 bytes of memory with value $AA
- .res 12, $AA
- </verb></tscreen>
-
-
-<sect1><tt>.RIGHT</tt><label id=".RIGHT"><p>
-
- Builtin function. Extracts the right part of a given token list.
-
- Syntax:
-
- <tscreen><verb>
- .RIGHT (<int expr>, <token list>)
+ .res 12, $AA
</verb></tscreen>
- The first integer expression gives the number of tokens to extract from
- the token list. The second argument is the token list itself.
-
- See also the <tt><ref id=".LEFT" name=".LEFT"></tt> and <tt><ref id=".MID"
- name=".MID"></tt> builtin functions.
-
<sect1><tt>.RODATA</tt><label id=".RODATA"><p>
See also the <tt><ref id=".SEGMENT" name=".SEGMENT"></tt> command.
+<sect1><tt>.SCOPE</tt><label id=".SCOPE"><p>
+
+ Start a nested lexical level with the given name. All new symbols from now
+ on are in the local lexical level and are accessible from outside only via
+ <ref id="scopesyntax" name="explicit scope specification">. Symbols defined
+ outside this local level may be accessed as long as their names are not used
+ for new symbols inside the level. Symbols names in other lexical levels do
+ not clash, so you may use the same names for identifiers. The lexical level
+ ends when the <tt><ref id=".ENDSCOPE" name=".ENDSCOPE"></tt> command is
+ read. Lexical levels may be nested up to a depth of 16 (this is an
+ artificial limit to protect against errors in the source).
+
+ Note: Macro names are always in the global level and in a separate name
+ space. There is no special reason for this, it's just that I've never
+ had any need for local macro definitions.
+
+ Example:
+
+ <tscreen><verb>
+ .scope Error ; Start new scope named Error
+ None = 0 ; No error
+ File = 1 ; File error
+ Parse = 2 ; Parse error
+ .endscope ; Close lexical level
+
+ ...
+ lda #Error::File ; Use symbol from scope Error
+ </verb></tscreen>
+
+ See: <tt/<ref id=".ENDSCOPE" name=".ENDSCOPE">/ and <tt/<ref id=".PROC"
+ name=".PROC">/
+
+
<sect1><tt>.SEGMENT</tt><label id=".SEGMENT"><p>
Switch to another segment. Code and data is always emitted into a
(and up to 65534 per executable). There are shortcut commands for
the most common segments ("CODE", "DATA" and "BSS").
- The command is followed by a string containing the segment name (there
- are some constraints for the name - as a rule of thumb use only those
- segment names that would also be valid identifiers). There may also be
- an optional attribute separated by a comma. Valid attributes are
- "<tt/zeropage/" and "<tt/absolute/".
+ The command is followed by a string containing the segment name (there are
+ some constraints for the name - as a rule of thumb use only those segment
+ names that would also be valid identifiers). There may also be an optional
+ address size separated by a colon. See the section covering <tt/<ref
+ id="address-sizes" name="address sizes">/ for more information.
- When specifying a segment for the first time, "absolute" is the
- default. For all other uses, the attribute specified the first time
- is the default.
+ The default address size for a segment depends on the memory model specified
+ on the command line. The default is "absolute", which means that you don't
+ have to use an address size modifier in most cases.
- "absolute" means that this is a segment with absolute addressing. That
- is, the segment will reside somewhere in core memory outside the zero
- page. "zeropage" means the opposite: The segment will be placed in the
- zero page and direct (short) addressing is possible for data in this
- segment.
+ "absolute" means that the is a segment with 16 bit (absolute) addressing.
+ That is, the segment will reside somewhere in core memory outside the zero
+ page. "zeropage" (8 bit) means that the segment will be placed in the zero
+ page and direct (short) addressing is possible for data in this segment.
Beware: Only labels in a segment with the zeropage attribute are marked
as reachable by short addressing. The `*' (PC counter) operator will
work as in other segments and will create absolute variable values.
- Example:
+ Please note that a segment cannot have two different address sizes. A
+ segment specified as zeropage cannot be declared as being absolute later.
+
+ Examples:
<tscreen><verb>
.segment "ROM2" ; Switch to ROM2 segment
- .segment "ZP2", zeropage ; New direct segment
- .segment "ZP2" ; Ok, will use last attribute
- .segment "ZP2", absolute ; Error, redecl mismatch
+ .segment "ZP2": zeropage ; New direct segment
+ .segment "ZP2" ; Ok, will use last attribute
+ .segment "ZP2": absolute ; Error, redecl mismatch
</verb></tscreen>
See: <tt><ref id=".BSS" name=".BSS"></tt>, <tt><ref id=".CODE"
id=".RODATA" name=".RODATA"></tt>
-<sect1><tt>.S
MART</tt><label id=".SMART"><p>
+<sect1><tt>.S
ETCPU</tt><label id=".SETCPU"><p>
- Switch on or off smart mode. The command must be followed by a '+' or
- '-' character to switch the option on or off respectively. The default
- is off (that is, the assembler doesn't try to be smart), but this
- default may be changed by the -s switch on the command line.
+ Switch the CPU instruction set. The command is followed by a string that
+ specifies the CPU. Possible values are those that can also be supplied to
+ the <tt><ref id="option--cpu" name="--cpu"></tt> command line option,
+ namely: 6502, 6502X, 65SC02, 65C02, 65816, sunplus and HuC6280. Please
+ note that support for the sunplus CPU is not available in the freeware
+ version, because the instruction set of the sunplus CPU is "proprietary
+ and confidential".
- In smart mode the assembler will track usage of the <tt/REP/ and <tt/SEP/
- instructions in 65816 mode and update the operand sizes accordingly. If
- the operand of such an instruction cannot be evaluated by the assembler
- (for example, because the operand is an imported symbol), a warning is
- issued. Beware: Since the assembler cannot trace the execution flow this
- may lead to false results in some cases. If in doubt, use the <tt/.Inn/ and
- <tt/.Ann/ instructions to tell the assembler about the current settings.
+ See: <tt><ref id=".CPU" name=".CPU"></tt>,
+ <tt><ref id=".IFP02" name=".IFP02"></tt>,
+ <tt><ref id=".IFP816" name=".IFP816"></tt>,
+ <tt><ref id=".IFPC02" name=".IFPC02"></tt>,
+ <tt><ref id=".IFPSC02" name=".IFPSC02"></tt>,
+ <tt><ref id=".P02" name=".P02"></tt>,
+ <tt><ref id=".P816" name=".P816"></tt>,
+ <tt><ref id=".PC02" name=".PC02"></tt>,
+ <tt><ref id=".PSC02" name=".PSC02"></tt>
- Example:
- <tscreen><verb>
- .smart ; Be smart
- .smart - ; Stop being smart
- </verb></tscreen>
+<sect1><tt>.SMART</tt><label id=".SMART"><p>
+ Switch on or off smart mode. The command must be followed by a '+' or '-'
+ character to switch the option on or off respectively. The default is off
+ (that is, the assembler doesn't try to be smart), but this default may be
+ changed by the -s switch on the command line.
-<sect1><tt>.STRAT</tt><label id=".STRAT"><p>
+ In smart mode the assembler will do the following:
- Builtin function. The function accepts a string and an index as
- arguments and returns the value of the character at the given position
- as an integer value. The index is zero based.
+ <itemize>
+ <item>Track usage of the <tt/REP/ and <tt/SEP/ instructions in 65816 mode
+ and update the operand sizes accordingly. If the operand of such an
+ instruction cannot be evaluated by the assembler (for example, because
+ the operand is an imported symbol), a warning is issued. Beware: Since
+ the assembler cannot trace the execution flow this may lead to false
+ results in some cases. If in doubt, use the <tt/.Inn/ and <tt/.Ann/
+ instructions to tell the assembler about the current settings.
+ <item>In 65816 mode, replace a <tt/RTS/ instruction by <tt/RTL/ if it is
+ used within a procedure declared as <tt/far/, or if the procedure has
+ no explicit address specification, but it is <tt/far/ because of the
+ memory model used.
+ </itemize>
Example:
<tscreen><verb>
- .macro M Arg
- ; Check if the argument string starts with '#'
- .if (.strat (Arg, 0) = '#')
- ...
- .endif
- .endmacro
+ .smart ; Be smart
+ .smart - ; Stop being smart
</verb></tscreen>
+ See: <tt><ref id=".A16" name=".A16"></tt>,
+ <tt><ref id=".A8" name=".A8"></tt>,
+ <tt><ref id=".I16" name=".I16"></tt>,
+ <tt><ref id=".I8" name=".I8"></tt>
-<sect1><tt>.STRING</tt><label id=".STRING"><p>
-
- Builtin function. The function accepts an argument in braces and converts
- this argument into a string constant. The argument may be an identifier, or
- a constant numeric value.
-
- Since you can use a string in the first place, the use of the function may
- not be obvious. However, it is useful in macros, or more complex setups.
-
- Example:
- <tscreen><verb>
- ; Emulate other assemblers:
- .macro section name
- .segment .string(name)
- .endmacro
- </verb></tscreen>
+<sect1><tt>.STRUCT</tt><label id=".STRUCT"><p>
+ Starts a struct definition. Structs are covered in a separate section named
+ <ref id="structs" name=""Structs and unions"">.
-<sect1><tt>.STRLEN</tt><label id=".STRLEN"><p>
+ See: <tt><ref id=".ENDSTRUCT" name=".ENDSTRUCT"></tt>
- Builtin function. The function accepts a string argument in braces and
- eveluates to the length of the string.
- Example:
+<sect1><tt>.SUNPLUS</tt><label id=".SUNPLUS"><p>
- The following macro encodes a string as a pascal style string with
- a leading length byte.
+ Enable the SunPlus instructions set. This command will not work in the
+ freeware version of the assembler, because the instruction set is
+ "proprietary and confidential".
- <tscreen><verb>
- .macro PString Arg
- .byte .strlen(Arg), Arg
- .endmacro
- </verb></tscreen>
+ See: <tt><ref id=".P02" name=".P02"></tt>, <tt><ref id=".PSC02"
+ name=".PSC02"></tt>, <tt><ref id=".PC02" name=".PC02"></tt>, and
+ <tt><ref id=".P816" name=".P816"></tt>
-<sect1><tt>.T
COUNT</tt><label id=".TCOUNT"><p>
+<sect1><tt>.T
AG</tt><label id=".TAG"><p>
- Builtin function. The function accepts a token list in braces. The
- function result is the number of tokens given as argument.
+ Allocate space for a struct or union.
Example:
- The <tt/ldax/ macro accepts the '#' token to denote immidiate addressing (as
- with the normal 6502 instructions). To translate it into two separate 8 bit
- load instructions, the '#' token has to get stripped from the argument:
-
<tscreen><verb>
- .macro ldax arg
- .if (.match (.mid (0, 1, arg), #))
- ; ldax called with immidiate operand
- lda #<(.right (.tcount (arg)-1, arg))
- ldx #>(.right (.tcount (arg)-1, arg))
- .else
- ...
- .endif
- .endmacro
- </verb></tscreen>
+ .struct Point
+ xcoord .word
+ ycoord .word
+ .endstruct
-
-<sect1><tt>.TIME</tt><label id=".TIME"><p>
-
- Reading this pseudo variable will give a constant integer value that
- represents the current time in POSIX standard (as seconds since the
- Epoch).
-
- It may be used to encode the time of translation somewhere in the created
- code.
-
- Example:
-
- <tscreen><verb>
- .dword .time ; Place time here
+ .bss
+ .tag Point ; Allocate 4 bytes
</verb></tscreen>
<sect1><tt>.WARNING</tt><label id=".WARNING"><p>
Force an assembly warning. The assembler will output a warning message
- preceeded by "User warning". This warning will always be output, even if
+ preceded by "User warning". This warning will always be output, even if
other warnings are disabled with the <tt><ref id="option-W" name="-W0"></tt>
command line option.
</verb></tscreen>
-<sect1><tt>.XMATCH</tt><label id=".XMATCH"><p>
-
- Builtin function. Matches two token lists against each other. This is
- most useful within macros, since macros are not stored as strings, but
- as lists of tokens.
-
- The syntax is
-
- <tscreen><verb>
- .XMATCH(<token list #1>, <token list #2>)
- </verb></tscreen>
-
- Both token list may contain arbitrary tokens with the exception of the
- terminator token (comma resp. right parenthesis) and
-
- <itemize>
- <item>end-of-line
- <item>end-of-file
- </itemize>
-
- Often a macro parameter is used for any of the token lists.
-
- The function compares tokens <em/and/ token values. If you need a function
- that just compares the type of tokens, have a look at the <tt><ref
- id=".MATCH" name=".MATCH"></tt> function.
-
- See: <tt><ref id=".MATCH" name=".MATCH"></tt>
-
-
<sect1><tt>.ZEROPAGE</tt><label id=".ZEROPAGE"><p>
Switch to the ZEROPAGE segment and mark it as direct (zeropage) segment.
.endmacro
</verb></tscreen>
-When calling the macro, you may give a parameter, and each occurence of
+When calling the macro, you may give a parameter, and each occurrence of
the name "addr" in the macro definition will be replaced by the given
parameter. So
are separated by commas. You are free to give less parameters than the
macro actually takes in the definition. You may also leave intermediate
parameters empty. Empty parameters are replaced by empty space (that is,
-they are removed when the macro is exanded). If you have a look at our
+they are removed when the macro is expanded). If you have a look at our
macro definition above, you will see, that replacing the "addr" parameter
by nothing will lead to wrong code in most lines. To help you, writing
macros with a variable parameter list, there are some control commands:
ldaxy 1,2,3 ; .PARAMCOUNT = 3
</verb></tscreen>
+Macro parameters may optionally be enclosed into curly braces. This allows the
+inclusion of tokens that would otherwise terminate the parameter (the comma in
+case of a macro parameter).
+
+<tscreen><verb>
+ .macro foo arg1, arg2
+ ...
+ .endmacro
+
+ foo ($00,x) ; Two parameters passed
+ foo {($00,x)} ; One parameter passed
+</verb></tscreen>
+
+In the first case, the macro is called with two parameters: '<tt/($00/'
+and 'x)'. The comma is not passed to the macro, since it is part of the
+calling sequence, not the parameters.
+
+In the second case, '($00,x)' is passed to the macro, this time
+including the comma.
+
+
+<sect1>Detecting parameter types<p>
+
+Sometimes it is nice to write a macro that acts differently depending on the
+type of the argument supplied. An example would be a macro that loads a 16 bit
+value from either an immediate operand, or from memory. The <tt/<ref
+id=".MATCH" name=".MATCH">/ and <tt/<ref id=".XMATCH" name=".XMATCH">/
+functions will allow you to do exactly this:
+
+<tscreen><verb>
+ .macro ldax arg
+ .if (.match (.left (1, {arg}), #))
+ ; immediate mode
+ lda #<(.right (.tcount ({arg})-1, {arg}))
+ ldx #>(.right (.tcount ({arg})-1, {arg}))
+ .else
+ ; assume absolute or zero page
+ lda arg
+ ldx 1+(arg)
+ .endif
+ .endmacro
+</verb></tscreen>
+
+Using the <tt/<ref id=".MATCH" name=".MATCH">/ function, the macro is able to
+check if its argument begins with a hash mark. If so, two immediate loads are
+emitted, Otherwise a load from an absolute zero page memory location is
+assumed. Please note how the curly braces are used to enclose parameters to
+pseudo functions handling token lists. This is necessary, because the token
+lists may include commas or parens, which would be treated by the assembler
+as end-of-list.
+
+The macro can be used as
+
+<tscreen><verb>
+ foo: .word $5678
+ ...
+ ldax #$1234 ; X=$12, A=$34
+ ...
+ ldax foo ; X=$56, A=$78
+</verb></tscreen>
+
<sect1>Recursive macros<p>
There's also a special macro to help writing recursive macros: <tt><ref
id=".EXITMACRO" name=".EXITMACRO"></tt> This command will stop macro expansion
-immidiately:
+immediately:
<tscreen><verb>
.macro push r1, r2, r3, r4, r5, r6, r7
+<sect1><tt>.MACPACK cbm</tt><p>
+
+The cbm macro package will define a macro named <tt/scrcode/. It takes a
+string as argument and places this string into memory translated into screen
+codes.
+
+
+<sect1><tt>.MACPACK cpu</tt><p>
+
+This macro package does not define any macros but constants used to examine
+the value read from the <tt/<ref id=".CPU" name=".CPU">/ pseudo variable. For
+each supported CPU a constant similar to
+
+<tscreen><verb>
+ CPU_6502
+ CPU_65SC02
+ CPU_65C02
+ CPU_65816
+ CPU_SUNPLUS
+ CPU_SWEET16
+ CPU_HUC6280
+</verb></tscreen>
+
+is defined. These constants may be used to determine the exact type of the
+currently enabled CPU. In addition to that, for each CPU instruction set,
+another constant is defined:
+
+<tscreen><verb>
+ CPU_ISET_6502
+ CPU_ISET_65SC02
+ CPU_ISET_65C02
+ CPU_ISET_65816
+ CPU_ISET_SUNPLUS
+ CPU_ISET_SWEET16
+ CPU_ISET_HUC6280
+</verb></tscreen>
+
+The value read from the <tt/<ref id=".CPU" name=".CPU">/ pseudo variable may
+be checked with <tt/<ref id="operators" name=".BITAND">/ to determine if the
+currently enabled CPU supports a specific instruction set. For example the
+65C02 supports all instructions of the 65SC02 CPU, so it has the
+<tt/CPU_ISET_65SC02/ bit set in addition to its native <tt/CPU_ISET_65C02/
+bit. Using
+
+<tscreen><verb>
+ .if (.cpu .bitand CPU_ISET_65SC02)
+ lda (sp)
+ .else
+ ldy #$00
+ lda (sp),y
+ .endif
+</verb></tscreen>
+
+it is possible to determine if the
+
+<tscreen><verb>
+ lda (sp)
+</verb></tscreen>
+
+instruction is supported, which is the case for the 65SC02, 65C02 and 65816
+CPUs (the latter two are upwards compatible to the 65SC02).
+
+
+
+<sect>Predefined constants<label id="predefined-constants"><p>
+
+For better orthogonality, the assembler defines similar symbols as the
+compiler, depending on the target system selected:
+
+<itemize>
+<item><tt/__ACE__/ - Target system is <tt/ace/
+<item><tt/__APPLE2__",/ - Target system is <tt/apple2/
+<item><tt/__APPLE2ENH__",/ - Target system is <tt/apple2enh/
+<item><tt/__ATARI__/ - Target system is <tt/atari/
+<item><tt/__ATMOS__",/ - Target system is <tt/atmos/
+<item><tt/__BBC__",/ - Target system is <tt/bbc/
+<item><tt/__C128__/ - Target system is <tt/c128/
+<item><tt/__C16__/ - Target system is <tt/c16/
+<item><tt/__C64__/ - Target system is <tt/c64/
+<item><tt/__CBM__/ - Target is a Commodore system
+<item><tt/__CBM510__/ - Target system is <tt/cbm510/
+<item><tt/__CBM610__/ - Target system is <tt/cbm610/
+<item><tt/__GEOS__",/ - Target system is <tt/geos/
+<item><tt/__LUNIX__",/ - Target system is <tt/lunix/
+<item><tt/__NES__",/ - Target system is <tt/nes/
+<item><tt/__PET__/ - Target system is <tt/pet/
+<item><tt/__PLUS4__/ - Target system is <tt/plus4/
+<item><tt/__SUPERVISION__",/ - Target system is <tt/supervision/
+<item><tt/__VIC20__/ - Target system is <tt/vic20/
+</itemize>
+
+
+<sect>Structs and unions<label id="structs"><p>
+
+<sect1>Overview<p>
+
+Structs and unions are special forms of <ref id="scopes" name="scopes">. They
+are to some degree comparable to their C counterparts. Both have a list of
+members. Each member allocates storage and may optionally have a name, which,
+in case of a struct, is the offset from the beginning and, in case of a union,
+is always zero.
+
+
+<sect1>Declaration<p>
+
+Here is an example for a very simple struct with two members and a total size
+of 4 bytes:
+
+<tscreen><verb>
+ .struct Point
+ xcoord .word
+ ycoord .word
+ .endstruct
+</verb></tscreen>
+
+A union shares the total space between all its members, its size is the same
+as that of the largest member.
+
+A struct or union must not necessarily have a name. If it is anonymous, no
+local scope is opened, the identifiers used to name the members are placed
+into the current scope instead.
+
+A struct may contain unnamed members and definitions of local structs. The
+storage allocators may contain a multiplier, as in the example below:
+
+<tscreen><verb>
+ .struct Circle
+ .struct Point
+ .word 2 ; Allocate two words
+ .endstruct
+ Radius .word
+ .endstruct
+</verb></tscreen>
+
+
+<sect1>The <tt/.TAG/ keyword<p>
+
+Using the <ref id=".TAG" name=".TAG"> keyword, it is possible to reserve space
+for an already defined struct or unions within another struct:
+
+<tscreen><verb>
+ .struct Point
+ xcoord .word
+ ycoord .word
+ .endstruct
+
+ .struct Circle
+ Origin .tag Point
+ Radius .byte
+ .endstruct
+</verb></tscreen>
+
+Space for a struct or union may be allocated using the <ref id=".TAG"
+name=".TAG"> directive.
+
+<tscreen><verb>
+ C: .tag Circle
+</verb></tscreen>
+
+Currently, members are just offsets from the start of the struct or union. To
+access a field of a struct, the member offset has to be added to the address
+of the struct itself:
+
+<tscreen><verb>
+ lda C+Circle::Radius ; Load circle radius into A
+</verb></tscreen>
+
+This may change in a future version of the assembler.
+
+
+<sect1>Limitations<p>
+
+Structs and unions are currently implemented as nested symbol tables (in fact,
+they were a by-product of the improved scoping rules). Currently, the
+assembler has no idea of types. This means that the <ref id=".TAG"
+name=".TAG"> keyword will only allocate space. You won't be able to initialize
+variables declared with <ref id=".TAG" name=".TAG">, and adding an embedded
+structure to another structure with <ref id=".TAG" name=".TAG"> will not make
+this structure accessible by using the '::' operator.
+
+
+
<sect>Module constructors/destructors<label id="condes"><p>
<em>Note:</em> This section applies mostly to C programs, so the explanation
useful for assembler programs.
-<sect1>
Module overview<p>
-Using the <tt><ref id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt> and <tt><ref
-id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> keywords it it possible to export
-functions in a special way. The linker is able to generate tables with all
-functions of a specific type. Such a table will <em>only</em> include symbols
-from object files that are linked into a specific executable. This may be used
-to add initialization and cleanup code for library modules.
+Using the <tt><ref id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt>, <tt><ref
+id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> and <tt><ref id=".INTERRUPTOR"
+name=".INTERRUPTOR"></tt> keywords it it possible to export functions in a
+special way. The linker is able to generate tables with all functions of a
+specific type. Such a table will <em>only</em> include symbols from object
+files that are linked into a specific executable. This may be used to add
+initialization and cleanup code for library modules, or a table of interrupt
+handler functions.
The C heap functions are an example where module initialization code is used.
All heap functions (<tt>malloc</tt>, <tt>free</tt>, ...) work with a few
</enum>
+<sect1>Calling order<p>
+
+The symbols are sorted in increasing priority order by the linker when using
+one of the builtin linker configurations, so the functions with lower
+priorities come first and are followed by those with higher priorities. The C
+library runtime subroutine that walks over the function tables calls the
+functions starting from the top of the table - which means that functions with
+a high priority are called first.
+
+So when using the C runtime, functions are called with high priority functions
+first, followed by low priority functions.
+
+
<sect1>Pitfalls<p>
-When creating and using module constructors and destructors, please take care
-of the following:
+When using these special symbols, please take care of the following:
<itemize>
The linker will only generate function tables, it will not generate code to
call these functions. If you're using the feature in some other than the
existing C environments, you have to write code to call all functions in a
-linker generated table yourself. See the <tt>condes</tt> module in the C
-runtime for an example on how to do this.
+linker generated table yourself. See the <tt/condes/ and <tt/callirq/ modules
+in the C runtime for an example on how to do this.
<item>
The linker will only add addresses of functions that are in modules linked to
the executable. This means that you have to be careful where to place the
-condes functions. If initialization is needed for a group of functions, be
-sure to place the initialization function into a module that is linked in
+condes functions. If initialization or an irq handler is needed for a group of
+functions, be sure to place the function into a module that is linked in
regardless of which function is called by the user.
<item>
<item>
Constructors and destructors may have priorities. These priorities determine
-the order of the functions in the table. If your intialization or cleanup code
+the order of the functions in the table. If your initialization or cleanup code
does depend on other initialization or cleanup code, you have to choose the
priority for the functions accordingly.
<item>
-Besides the <tt><ref id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt> and <tt><ref
-id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> statements, there is also a more
-generic command: <tt><ref id=".CONDES" name=".CONDES"></tt>. This allows to
-specify an additional type. Predefined types are 0 (constructor) and 1
-(destructor). The linker generates a separate table for each type on request.
+Besides the <tt><ref id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt>, <tt><ref
+id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> and <tt><ref id=".INTERRUPTOR"
+name=".INTERRUPTOR"></tt> statements, there is also a more generic command:
+<tt><ref id=".CONDES" name=".CONDES"></tt>. This allows to specify an
+additional type. Predefined types are 0 (constructor), 1 (destructor) and 2
+(interruptor). The linker generates a separate table for each type on request.
</itemize>
+<sect>Porting sources from other assemblers<p>
+Sometimes it is necessary to port code written for older assemblers to ca65.
+In some cases, this can be done without any changes to the source code by
+using the emulation features of ca65 (see <tt><ref id=".FEATURE"
+name=".FEATURE"></tt>). In other cases, it is necessary to make changes to the
+source code.
+
+Probably the biggest difference is the handling of the <tt><ref id=".ORG"
+name=".ORG"></tt> directive. ca65 generates relocatable code, and placement is
+done by the linker. Most other assemblers generate absolute code, placement is
+done within the assembler and there is no external linker.
+
+In general it is not a good idea to write new code using the emulation
+features of the assembler, but there may be situations where even this rule is
+not valid.
+
+<sect1>TASS<p>
+
+You need to use some of the ca65 emulation features to simulate the behaviour
+of such simple assemblers.
+
+<enum>
+<item>Prepare your sourcecode like this:
+
+<tscreen><verb>
+ ; if you want TASS style labels without colons
+ .feature labels_without_colons
+
+ ; if you want TASS style character constants
+ ; ("a" instead of the default 'a')
+ .feature loose_char_term
+
+ .word *+2 ; the cbm load address
+
+ [yourcode here]
+</verb></tscreen>
+
+notice that the two emulation features are mostly useful for porting
+sources originally written in/for TASS, they are not needed for the
+actual "simple assembler operation" and are not recommended if you are
+writing new code from scratch.
+
+<item>Replace all program counter assignments (which are not possible in ca65
+by default, and the respective emulation feature works different from what
+you'd expect) by another way to skip to memory locations, for example the
+<tt><ref id=".RES" name=".RES"></tt> directive.
+
+<tscreen><verb>
+ ; *=$2000
+ .res $2000-* ; reserve memory up to $2000
+</verb></tscreen>
+
+Please note that other than the original TASS, ca65 can never move the program
+counter backwards - think of it as if you are assembling to disk with TASS.
+
+<item>Conditional assembly (<tt/.ifeq//<tt/.endif//<tt/.goto/ etc.) must be
+rewritten to match ca65 syntax. Most importantly notice that due to the lack
+of <tt/.goto/, everything involving loops must be replaced by
+<tt><ref id=".REPEAT" name=".REPEAT"></tt>.
+
+<item>To assemble code to a different address than it is executed at, use the
+<tt><ref id=".ORG" name=".ORG"></tt> directive instead of
+<tt/.offs/-constructs.
+
+<tscreen><verb>
+ .org $1800
+
+ [floppy code here]
+
+ .reloc ; back to normal
+</verb></tscreen>
+
+<item>Then assemble like this:
+
+<tscreen><verb>
+ cl65 --start-addr 0x0ffe -t none myprog.s -o myprog.prg
+</verb></tscreen>
+
+Note that you need to use the actual start address minus two, since two bytes
+are used for the cbm load address.
+
+</enum>
<sect>Bugs/Feedback<p>
<sect>Copyright<p>
-ca65 (and all cc65 binutils) are (C) Copyright 1998-2001 Ullrich von
+ca65 (and all cc65 binutils) are (C) Copyright 1998-2003 Ullrich von
Bassewitz. For usage of the binaries and/or sources the following
conditions do apply:
projects / cc65 / blobdiff