<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>
Set the default for the CPU type. The option takes a parameter, which
may be one of
- 6502, 65SC02, 65C02, 65816 and sunplus
+ 6502, 65SC02, 65C02, 65816, sunplus, sweet16, HuC6280
- The last one (sunplus) is not available in the freeware version, because the
- instruction set of the sunplus CPU is "proprietary and 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>
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:
<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
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>
+
+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 $0B.
+<item><tt>ARR: A:=(A and #{imm})/2;</tt>
+<item><tt>AXS: X:=A and X-#{imm};</tt>
+<item><tt>DCP: {adr}:={adr}-1; A-{adr};</tt>
+<item><tt>ISC: {adr}:={adr}+1; A:=A-{adr};</tt>
+<item><tt>LAS: A,X,S:={adr} and S;</tt>
+<item><tt>LAX: A,X:={adr};</tt>
+<item><tt>RLA: {adr}:={adr}rol; A:=A and {adr};</tt>
+<item><tt>RRA: {adr}:={adr}ror; A:=A adc {adr};</tt>
+<item><tt>SAX: {adr}:=A and X;</tt>
+<item><tt>SLO: {adr}:={adr}*2; A:=A or {adr};</tt>
+<item><tt>SRE: {adr}:={adr}/2; A:=A xor {adr};</tt>
+</itemize>
+
+
+
+<sect1>sweet16 mode<label id="sweet16-mode"><p>
+
+SWEET 16 is an interpreter for a pseudo 16 bit CPU written by Steve Wozniak
+for the Apple ][ machines. It is available in the Apple ][ ROM. ca65 can
+generate code for this pseudo CPU when switched into sweet16 mode. The
+following is special in sweet16 mode:
+
+<itemize>
+
+<item>The '@' character denotes indirect addressing and is no longer available
+for cheap local labels. If you need cheap local labels, you will have to
+switch to another lead character using the <tt/<ref id=".LOCALCHAR"
+name=".LOCALCHAR">/ command.
+
+<item>Registers are specified using <tt/R0/ .. <tt/R15/. In sweet16 mode,
+these identifiers are reserved words.
+
+</itemize>
+
+Please note that the assembler does neither supply the interpreter needed for
+SWEET 16 code, nor the zero page locations needed for the SWEET 16 registers,
+nor does it call the interpreter. All this must be done by your program. Apple
+][ programmers do probably know how to use sweet16 mode.
+
+For more information about SWEET 16, see
+<htmlurl url="http://www.6502.org/source/interpreters/sweet16.htm"
+name="http://www.6502.org/source/interpreters/sweet16.htm">.
+
<sect1>Number format<p>
-For literal values, the assembler accepts the widely used number formats:
-A preceeding '$' 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.
+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>
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
<sect1>Available operators<label id="operators"><p>
-Available operators sorted by precedence:
-
-<tscreen><verb>
- Op Description Precedence
- -------------------------------------------------------------------
- Builtin string functions 0
-
- Builtin pseudo variables 1
- Builtin pseudo functions 1
- + Unary plus 1
- - Unary minus 1
- ~ Unary bitwise not 1
- .BITNOT Unary bitwise not 1
- < Low byte operator 1
- > High byte operator 1
- ^ Bank 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.
-
-<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>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
are in global scope.
-<sect1>
A special scope: cheap locals<p>
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.
error" is output.
Of course the most simple solution for the problem is to move the definition
-of <tt/foo/ in scope <tt/inner/ upwards, so it preceeds its use. There may be
+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:
without a name (using the <tt/<ref id=".SCOPE" name=".SCOPE">/ command).
A special syntax is used to specify the global scope: If a symbol or scope is
-preceeded by the namespace token, the global scope is searched:
+preceded by the namespace token, the global scope is searched:
<tscreen><verb>
bar = 3
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 preceeding definition. This means that in the following
+used without a preceding definition. This means that in the following
example:
<tscreen><verb>
.endscope
</verb></tscreen>
-
-<sect>Address sizes<label id="address-sizes"><p>
+
+<sect>Address sizes and memory models<label id="address-sizes"><p>
+
+<sect1>Address sizes<p>
+
+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.
+
+Possible address sizes are:
+
+<itemize>
+<item>Zeropage or direct (8 bits)
+<item>Absolute (16 bits)
+<item>Far (24 bits)
+<item>Long (32 bits)
+</itemize>
+
+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:
+
+<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>
+
+
+<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.
+
+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.
+
+
+<sect1>Address sizes of symbols<p>
+
+
+
+
+<sect1>Memory models<p>
+
+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.
+
<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. As an example, the <tt/.IFBLANK/ statement
- may be replaced by
+ 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)
+ .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
- concatentation of all arguments. This function is most useful in macros and
+ 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.
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.
</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. 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
- (immidiate addressing mode), use something like this:
+ (immediate addressing mode), use something like this:
<tscreen><verb>
.macro ldax arg
...
- .if (.match (.left (1, arg), #))
+ .if (.match (.left (1, {arg}), #))
- ; ldax called with immidiate operand
+ ; ldax called with immediate operand
...
.endif
<item>end-of-file
</itemize>
- Often a macro parameter is used for any of the token lists.
+ 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
<tscreen><verb>
.macro asr arg
- .if (.not .blank(arg)) .and (.not .match (arg, a))
+ .if (.not .blank(arg)) .and (.not .match ({arg}, a))
.error "Syntax error"
.endif
.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 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
- (immidiate addressing mode), use something like this:
+ (immediate addressing mode), use something like this:
<tscreen><verb>
.macro ldax arg
...
- .if (.match (.mid (0, 1, arg), #))
+ .if (.match (.mid (0, 1, {arg}), #))
- ; ldax called with immidiate operand
+ ; ldax called with immediate operand
...
.endif
.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 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.
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 choosen over the
+ of a name represents both, a scope and a symbol, the scope is chosen over the
symbol.
After the following code:
</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
<sect1><tt>.STRLEN</tt><label id=".STRLEN"><p>
Builtin function. The function accepts a string argument in braces and
- eveluates to the length of the string.
+ evaluates to the length of the string.
Example:
<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.
+ 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 immidiate addressing (as
+ 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 immidiate operand
- lda #<(.right (.tcount (arg)-1, arg))
- ldx #>(.right (.tcount (arg)-1, 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
<item>end-of-file
</itemize>
- Often a macro parameter is used for any of the token lists.
+ 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
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.
+ create 16 bit operands for immediate accumulator addressing mode.
See also: <tt><ref id=".SMART" name=".SMART"></tt>
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 adressing mode.
+ create 8 bit operands for immediate accu addressing mode.
See also: <tt><ref id=".SMART" name=".SMART"></tt>
<sect1><tt>.ASSERT</tt><label id=".ASSERT"><p>
Add an assertion. The command is followed by an expression, an action
- specifier and a message that is output in case the assertion fails. The
- action specifier may be one of <tt/warning/ or <tt/error/. The assertion
- is passed to the linker and will be evaluated when segment placement has
- been done.
+ 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:
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.
+ suppressed in both the assembler and linker.
<sect1><tt>.AUTOIMPORT</tt><label id=".AUTOIMPORT"><p>
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
+ 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.
<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/.
+ 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
.condes ModInit, 0, 16
</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.
+ 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>
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 preceeding plus
- one. This behaviour may be overriden by an explicit assignment. Two symbols
+ 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:
<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">.
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.
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>.INTERRUPTOR</tt><label id=".INTERRUPTOR"><p>
+
+ 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.
+
+ 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.
+
+ 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:
+
+ <tscreen><verb>
+ .interruptor IrqHandler
+ .interruptor Handler, 16
+ </verb></tscreen>
+
+ 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>
Switch on or off line continuations using the backslash character
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.
- cbm Defines the scrcode macro
- cpu Defines constants for the .CPU variable
</verb></tscreen>
Including a macro package twice, or including a macro package that
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:
See: <tt><ref id=".POPSEG" name=".POPSEG"></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>.REPEAT</tt><label id=".REPEAT"><p>
Repeat all commands between <tt/.REPEAT/ and <tt><ref id=".ENDREPEAT"
<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
None = 0 ; No error
File = 1 ; File error
Parse = 2 ; Parse error
- .endproc ; Close lexical level
+ .endscope ; Close lexical level
...
lda #Error::File ; Use symbol from scope Error
(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"
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, 65SC02, 65C02, 65816 and sunplus. 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".
+ 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".
See: <tt><ref id=".CPU" name=".CPU"></tt>,
<tt><ref id=".IFP02" name=".IFP02"></tt>,
<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.
+ 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.
In smart mode the assembler will do the following:
<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.
.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>
<tscreen><verb>
.macro ldax arg
- .if (.match (.left (1, arg), #))
+ .if (.match (.left (1, {arg}), #))
; immediate mode
- lda #<(.right (.tcount (arg)-1, arg))
- ldx #>(.right (.tcount (arg)-1, arg))
+ lda #<(.right (.tcount ({arg})-1, {arg}))
+ ldx #>(.right (.tcount ({arg})-1, {arg}))
.else
; assume absolute or zero page
lda arg
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. So this macro can be used as
+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
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
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
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
+<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:
.endstruct
</verb></tscreen>
-Using the <ref id=".TAG" name=".TAG"> keyword, it is possible to embedd
-already defined structs or unions in structs:
+
+<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
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
<sect1>Calling order<p>
-Both, constructors and destructors 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
-constructor and destructor tables calls the functions starting from the top of
-the table - which means that functions with a high priority are called first.
+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, both constructors and destructors are called with
-high priority functions first, followed by low priority functions.
+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>
<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 another memory location, for example
-the <tt><ref id=".RES" name=".RES"></tt>directive.
+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>
-notice that other than the original TASS, ca65 can never move the
-programmcounter backwards - think of it as if you are assembling to disc with
-TASS.
+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
cl65 --start-addr 0x0ffe -t none myprog.s -o myprog.prg
</verb></tscreen>
-notice that you need to use the actual start address minus two, since two
-bytes are used for the cbm load address.
+Note that you need to use the actual start address minus two, since two bytes
+are used for the cbm load address.
</enum>
projects / cc65 / blobdiff