1 <!doctype linuxdoc system>
4 <title>ca65 Users Guide
5 <author>Ullrich von Bassewitz, <htmlurl url="mailto:uz@cc65.org" name="uz@cc65.org">
6 <date>19.07.2000, 29.11.2000
9 ca65 is a powerful macro assembler for the 6502, 65C02 and 65816 CPUs. It is
10 used as a companion assembler for the cc65 crosscompiler, but it may also be
11 used as a standalone product.
14 <!-- Table of contents -->
17 <!-- Begin the document -->
21 ca65 is a replacement for the ra65 assembler that was part of the cc65 C
22 compiler, originally developed by John R. Dunning. I had some problems with
23 ra65 and the copyright does not permit some things which I wanted to be
24 possible, so I decided to write a completely new assembler/linker/archiver
25 suite for the cc65 compiler. ca65 is part of this suite.
27 Some parts of the assembler (code generation and some routines for symbol
28 table handling) are taken from an older crossassembler named a816 written
29 by me a long time ago.
32 <sect1>Design criteria<p>
34 Here's a list of the design criteria, that I considered important for the
39 <item> The assembler must support macros. Macros are not essential, but they
40 make some things easier, especially when you use the assembler in the
41 backend of a compiler.
42 <item> The assembler must support the newer 65C02 and 65816 CPUs. I have been
43 thinking about a 65816 backend for the C compiler, and even my old
44 a816 assembler had support for these CPUs, so this wasn't really a
46 <item> The assembler must produce relocatable code. This is necessary for the
47 compiler support, and it is more convenient.
48 <item> Conditional assembly must be supported. This is a must for bigger
49 projects written in assembler (like Elite128).
50 <item> The assembler must support segments, and it must support more than
51 three segments (this is the count, most other assemblers support).
52 Having more than one code segments helps developing code for systems
53 with a divided ROM area (like the C64).
54 <item> The linker must be able to resolve arbitrary expressions. It should
55 be able to get things like
62 <item> True lexical nesting for symbols. This is very convenient for larger
64 <item> "Cheap" local symbols without lexical nesting for those quick, late
66 <item> I liked the idea of "options" as Anre Fachats .o65 format has it, so I
67 introduced the concept into the object file format use by the new cc65
69 <item> The assembler will be a one pass assembler. There was no real need for
70 this decision, but I've written several multipass assemblers, and it
71 started to get boring. A one pass assembler needs much more elaborated
72 data structures, and because of that it's much more fun:-)
73 <item> Non-GPLed code that may be used in any project without restrictions or
74 fear of "GPL infecting" other code.
82 <sect1>Command line option overview<p>
84 The assembler accepts the following options:
87 ---------------------------------------------------------------------------
88 Usage: ca65 [options] file
90 -g Add debug info to object file
92 -i Ignore case of symbols
93 -l Create a listing if assembly was ok
94 -o name Name the output file
96 -t sys Set the target system
98 -D name[=value] Define a symbol
99 -I dir Set an include directory search path
100 -U Mark unresolved symbols as import
101 -V Print the assembler version
102 -W n Set warning level n
105 --auto-import Mark unresolved symbols as import
106 --cpu type Set cpu type
107 --debug-info Add debug info to object file
108 --feature name Set an emulation feature
109 --help Help (this text)
110 --ignore-case Ignore case of symbols
111 --include-dir dir Set an include directory search path
112 --listing Create a listing if assembly was ok
113 --pagelength n Set the page length for the listing
114 --smart Enable smart mode
115 --target sys Set the target system
116 --verbose Increase verbosity
117 --version Print the assembler version
118 ---------------------------------------------------------------------------
122 <sect1>Command line options in detail<p>
124 Here is a description of all the command line options:
128 <tag><tt>--cpu type</tt></tag>
130 Set the default for the CPU type. The option takes a parameter, which
133 6502, 65C02, 65816 and sunplus
135 The latter (sunplus) is not available in the freeware version, because the
136 instruction set of the sunplus CPU is "confidential".
139 <label id="option--feature">
140 <tag><tt>--feature name</tt></tag>
142 Enable an emulation feature. This is identical as using <tt/.FEATURE/
143 in the source with two exceptions: Feature names must be lower case, and
144 each feature must be specified by using an extra <tt/--feature/ option,
145 comma separated lists are not allowed.
147 See the discussion of the <tt><ref id=".FEATURE" name=".FEATURE"></tt>
148 command for a list of emulation features.
151 <label id="option-g">
152 <tag><tt>-g, --debug-info</tt></tag>
154 When this option (or the equivalent control command <tt/.DEBUGINFO/) is
155 used, the assembler will add a section to the object file that contains
156 all symbols (including local ones) together with the symbol values and
157 source file positions. The linker will put these additional symbols into
158 the VICE label file, so even local symbols can be seen in the VICE
162 <tag><tt>-h, --help</tt></tag>
164 Print the short option summary shown above.
167 <tag><tt>-i, --ignore-case</tt></tag>
169 This option makes the assembler case insensitive on identifiers and labels.
170 This option will override the default, but may itself be overriden by the
171 <tt><ref id=".CASE" name=".CASE"></tt> control command.
174 <tag><tt>-l, --listing</tt></tag>
176 Generate an assembler listing. The listing file will always have the
177 name of the main input file with the extension replaced by ".lst". This
178 may change in future versions.
181 <tag><tt>-o name</tt></tag>
183 The default output name is the name of the input file with the extension
184 replaced by ".o". If you don't like that, you may give another name with
185 the -o option. The output file will be placed in the same directory as
186 the source file, or, if -o is given, the full path in this name is used.
189 <tag><tt>--pagelength n</tt></tag>
191 sets the length of a listing page in lines. See the <tt><ref
192 id=".PAGELENGTH" name=".PAGELENGTH"></tt> directive for more information.
195 <tag><tt>-s, --smart-mode</tt></tag>
197 In smart mode (enabled by -s or the <tt><ref id=".SMART" name=".SMART"></tt>
198 pseudo instruction) the assembler will track usage of the <tt/REP/ and
199 <tt/SEP/ instructions in 65816 mode and update the operand sizes
200 accordingly. If the operand of such an instruction cannot be evaluated by
201 the assembler (for example, because the operand is an imported symbol), a
204 Beware: Since the assembler cannot trace the execution flow this may
205 lead to false results in some cases. If in doubt, use the .ixx and .axx
206 instructions to tell the assembler about the current settings. Smart
207 mode is off by default.
210 <label id="option-t">
211 <tag><tt>-t sys, --target sys</tt></tag>
213 Set the target system. This will enable translation of character strings
214 and character constants into the character set of the target platform.
215 The default for the target system is "none", which means that no translation
216 will take place. The assembler supports the same target systems as the
217 compiler, see there for a list.
220 <tag><tt>-v, --verbose</tt></tag>
222 Increase the assembler verbosity. Usually only needed for debugging
223 purposes. You may use this option more than one time for even more
227 <tag><tt>-D</tt></tag>
229 This option allows you to define symbols on the command line. Without a
230 value, the symbol is defined with the value zero. When giving a value,
231 you may use the '$' prefix for hexadecimal symbols. Please note
232 that for some operating systems, '$' has a special meaning, so
233 you may have to quote the expression.
236 <tag><tt>-I dir, --include-dir dir</tt></tag>
238 Name a directory which is searched for include files. The option may be
239 used more than once to specify more than one directory to search. The
240 current directory is always searched first before considering any
241 additional directores.
244 <tag><tt>-U, --auto-import</tt></tag>
246 Mark symbols that are not defined in the sources as imported symbols. This
247 should be used with care since it delays error messages about typos and such
248 until the linker is run. The compiler uses the equivalent of this switch
249 (<tt><ref id=".AUTOIMPORT" name=".AUTOIMPORT"></tt>) to enable auto imported
250 symbols for the runtime library. However, the compiler is supposed to
251 generate code that runs through the assembler without problems, something
252 which is not always true for assembler programmers.
255 <tag><tt>-V, --version</tt></tag>
257 Print the version number of the assembler. If you send any suggestions
258 or bugfixes, please include the version number.
261 <label id="option-W">
262 <tag><tt>-Wn</tt></tag>
264 Set the warning level for the assembler. Using -W2 the assembler will
265 even warn about such things like unused imported symbols. The default
266 warning level is 1, and it would probably be silly to set it to
273 <sect>Input format<p>
275 The assembler accepts the standard 6502/65816 assembler syntax. One line may
276 contain a label (which is identified by a colon), and, in addition to the
277 label, an assembler mnemonic, a macro, or a control command (see section <ref
278 id="control-commands" name="Control Commands"> for supported control
279 commands). Alternatively, the line may contain a symbol definition using the
280 '=' token. Everything after a semicolon is handled as a comment (that is, it
283 Here are some examples for valid input lines:
286 Label: ; A label and a comment
287 lda #$20 ; A 6502 instruction plus comment
288 L1: ldx #$20 ; Same with label
289 L2: .byte "Hello world" ; Label plus control command
290 mymac $20 ; Macro expansion
291 MySym = 3*L1 ; Symbol definition
292 MaSym = Label ; Another symbol
295 The assembler accepts all valid 6502 mnemonics when in 6502 mode (the
296 default). The assembler accepts all valid 65SC02 mnemonics when in 65SC02 mode
297 (after a <tt><ref id=".PC02" name=".PC02"></tt> command is found). The
298 assembler accepts all valid 65816 mnemonics with a few exceptions after a
299 .P816 command is found. These exceptions are listed below.
301 In 65816 mode several aliases are accepted in addition to the official
305 BGE is an alias for BCS
306 BLT is an alias for BCC
307 CPA is an alias for CMP
308 DEA is an alias for DEC A
309 INA is an alias for INC A
310 SWA is an alias for XBA
311 TAD is an alias for TCD
312 TAS is an alias for TCS
313 TDA is an alias for TDC
314 TSA is an alias for TSC
317 Evaluation of banked expressions in 65816 mode differs slightly from the
320 Instead of accepting a 24 bit address (something that is difficult for
321 the assembler to determine and would have required one more special
322 .import command), the bank and the absolute address in that bank are
326 jsl 3.$1234 ; Call subroutine at $1234 in bank 3
329 For literal values, the assembler accepts the widely used number formats:
330 A preceeding '$' denotes a hex value, a preceeding '%' denotes a
331 binary value, and a bare number is interpeted as a decimal. There are
332 currently no octal values and no floats.
339 <sect1>Expression evaluation<p>
341 All expressions are evaluated with (at least) 32 bit precision. An
342 expression may contain constant values and any combination of internal and
343 external symbols. Expressions that cannot be evaluated at assembly time
344 are stored inside the object file for evaluation by the linker.
345 Expressions referencing imported symbols must always be evaluated by the
349 <sect1>Size of an expressions result<p>
351 Sometimes, the assembler must know about the size of the value that is the
352 result of an expression. This is usually the case, if a decision has to be
353 made, to generate a zero page or an absolute memory references. In this
354 case, the assembler has to make some assumptions about the result of an
358 <item> If the result of an expression is constant, the actual value is
359 checked to see if it's a byte sized expression or not.
360 <item> If the expression is explicitly casted to a byte sized expression by
361 one of the '>'/'<' operators, it is a byte expression.
362 <item> If this is not the case, and the expression contains a symbol,
363 explicitly declared as zero page symbol (by one of the .importzp or
364 .exportzp instructions), then the whole expression is assumed to be
366 <item> If the expression contains symbols that are not defined, and these
367 symbols are local symbols, the enclosing scopes are searched for a
368 symbol with the same name. If one exists and this symbol is defined,
369 it's attributes are used to determine the result size.
370 <item> In all other cases the expression is assumed to be word sized.
373 Note: If the assembler is not able to evaluate the expression at assembly
374 time, the linker will evaluate it and check for range errors as soon as
378 <sect1>Boolean expressions<p>
380 In the context of a boolean expression, any non zero value is evaluated as
381 true, any other value to false. The result of a boolean expression is 1 if
382 it's true, and zero if it's false. There are boolean operators with extrem
383 low precedence with version 2.x (where x > 0). The <tt/.AND/ and <tt/.OR/
384 operators are shortcut operators. That is, if the result of the expression is
385 already known, after evaluating the left hand side, the right hand side is
389 <sect1>Available operators<p>
391 Available operators sorted by precedence:
394 Op Description Precedence
395 -------------------------------------------------------------------
396 .CONCAT Builtin function 0
397 .LEFT Builtin function 0
398 .MID Builtin function 0
399 .RIGHT Builtin function 0
400 .STRING Builtin function 0
402 * Builtin pseudo variable (r/o) 1
403 .BLANK Builtin function 1
404 .CONST Builtin function 1
405 .CPU Builtin pseudo variable (r/o) 1
406 .DEFINED Builtin function 1
407 .MATCH Builtin function 1
408 .TCOUNT Builtin function 1
409 .XMATCH Builtin function 1
410 .PARAMCOUNT Builtin pseudo variable (r/o) 1
411 .REFERENCED Builtin function 1
412 :: Global namespace override 1
415 ~ Unary bitwise not 1
416 .BITNOT Unary bitwise not 1
417 < Low byte operator 1
418 > High byte operator 1
422 .MOD Modulo operation 2
424 .BITAND Bitwise and 2
426 .BITXOR Bitwise xor 2
427 << Shift left operator 2
428 .SHL Shift left operator 2
429 >> Shift right operator
430 .SHR Shift right operator 2
437 = Compare operation (equal) 4
438 <> Compare operation (not equal) 4
439 < Compare operation (less) 4
440 > Compare operation (greater) 4
441 <= Compare operation (less or equal) 4
442 >= Compare operation (greater or equal) 4
444 && Boolean and 5
456 To force a specific order of evaluation, braces may be used as usual.
458 Some of the pseudo variables mentioned above need some more explanation:
461 * This symbol is replaced by the value of the program
462 counter at start of the current instruction. Note, that
463 '*' yields a rvalue, that means, you cannot assign to it.
464 Use <tt/.ORG/ to set the program counter in sections with
471 <sect>Symbols and labels<p>
473 The assembler allows you to use symbols instead of naked values to make
474 the source more readable. There are a lot of different ways to define and
475 use symbols and labels, giving a lot of flexibility.
478 <sect1>Numeric constants<p>
480 Numeric constants are defined using the equal sign. After doing
486 may use the symbol "two" in every place where a number is expected, and it is
487 evaluated to the value 2 in this context. An example would be
494 <sect1>Standard labels<p>
496 A label is defined by writing the name of the label at the start of the line
497 (before any instruction mnemonic, macro or pseudo directive), followed by a
498 colon. This will declare a symbol with the given name and the value of the
499 current program counter.
502 <sect1>Local labels and symbols<p>
504 Using the <tt><ref id=".PROC" name=".PROC"></tt> directive, it is possible to
505 create regions of code where the names of labels and symbols are local to this
506 region. They are not known outside of this region and cannot be accessed from
507 there. Such regions may be nested like PROCEDUREs in Pascal.
509 See the description of the <tt><ref id=".PROC" name=".PROC"></tt>
510 directive for more information.
513 <sect1>Cheap local labels<p>
515 Cheap local labels are defined like standard labels, but the name of the
516 label must begin with a special symbol (usually '@', but this can be
517 changed by the <tt><ref id=".LOCALCHAR" name=".LOCALCHAR"></tt>
520 Cheap local labels are visible only between two non cheap labels. As soon as a
521 standard symbol is encountered (this may also be a local symbol if inside a
522 region defined with the <tt><ref id=".PROC" name=".PROC"></tt> directive), the
523 cheap local symbol goes out of scope.
525 You may use cheap local labels as an easy way to reuse common label
526 names like "Loop". Here is an example:
529 Clear: lda #$00 ; Global label
531 @Loop: sta Mem,y ; Local label
535 Sub: ... ; New global label
536 bne @Loop ; ERROR: Unknown identifier!
539 <sect1>Unnamed labels<p>
541 If you really want to write messy code, there are also unnamed
542 labels. These labels do not have a name (you guessed that already,
543 didn't you?). A colon is used to mark the absence of the name.
545 Unnamed labels may be accessed by using the colon plus several minus
546 or plus characters as a label designator. Using the '-' characters
547 will create a back reference (use the n'th label backwards), using
548 '+' will create a forward reference (use the n'th label in forward
549 direction). An example will help to understand this:
571 As you can see from the example, unnamed labels will make even short
572 sections of code hard to understand, because you have to count labels
573 to find branch targets (this is the reason why I for my part do
574 prefer the "cheap" local labels). Nevertheless, unnamed labels are
575 convenient in some situations, so it's your decision.
578 <sect1>Using macros to define labels and constants<p>
580 While there are drawbacks with this approach, it may be handy in some
581 situations. Using <tt><ref id=".DEFINE" name=".DEFINE"></tt>, it is
582 possible to define symbols or constants that may be used elsewhere. Since
583 the macro facility works on a very low level, there is no scoping. On the
584 other side, you may also define string constants this way (this is not
585 possible with the other symbol types).
591 .DEFINE version "SOS V2.3"
593 four = two * two ; Ok
596 .PROC ; Start local scope
597 two = 3 ; Will give "2 = 3" - invalid!
602 <sect1>Symbols and <tt>.DEBUGINFO</tt><p>
604 If <tt><ref id=".DEBUGINFO" name=".DEBUGINFO"></tt> is enabled (or <ref
605 id="option-g" name="-g"> is given on the command line), global, local and
606 cheap local labels are written to the object file and will be available in the
607 symbol file via the linker. Unnamed labels are not written to the object file,
608 because they don't have a name which would allow to access them.
612 <sect>Control commands<label id="control-commands">
615 Here's a list of all control commands and a description, what they do:
618 <sect1><tt>.A16</tt><label id=".A16"><p>
620 Valid only in 65816 mode. Switch the accumulator to 16 bit.
622 Note: This command will not emit any code, it will tell the assembler to
623 create 16 bit operands for immediate accumulator adressing mode.
625 See also: <tt><ref id=".SMART" name=".SMART"></tt>
628 <sect1><tt>.A8</tt><label id=".A8"><p>
630 Valid only in 65816 mode. Switch the accumulator to 8 bit.
632 Note: This command will not emit any code, it will tell the assembler to
633 create 8 bit operands for immediate accu adressing mode.
635 See also: <tt><ref id=".SMART" name=".SMART"></tt>
638 <sect1><tt>.ADDR</tt><label id=".ADDR"><p>
640 Define word sized data. In 6502 mode, this is an alias for <tt/.WORD/ and
641 may be used for better readability if the data words are address values.
642 In 65816 mode, the address is forced to be 16 bit wide to fit into the
643 current segment. See also <tt/.FARADDR/. The command must be followed by a
644 sequence of (not necessarily constant) expressions.
649 .addr $0D00, $AF13, _Clear
652 See: <tt><ref id=".FARADDR" name=".FARADDR"></tt>
655 <sect1><tt>.ALIGN</tt><label id=".ALIGN"><p>
657 Align data to a given boundary. The command expects a constant integer
658 argument that must be a power of two, plus an optional second argument
659 in byte range. If there is a second argument, it is used as fill value,
660 otherwise the value defined in the linker configuration file is used
661 (the default for this value is zero).
663 Since alignment depends on the base address of the module, you must
664 give the same (or a greater) alignment for the segment when linking.
665 The linker will give you a warning, if you don't do that.
674 <sect1><tt>.ASCIIZ</tt><label id=".ASCIIZ"><p>
676 Define a string with a trailing zero.
681 Msg: .asciiz "Hello world"
684 This will put the string "Hello world" followed by a binary zero into
685 the current segment. There may be more strings separated by commas, but
686 the binary zero is only appended once (after the last one).
689 <sect1><tt>.AUTOIMPORT</tt><label id=".AUTOIMPORT"><p>
691 Is followd by a plus or a minus character. When switched on (using a
692 +), undefined symbols are automatically marked as import instead of
693 giving errors. When switched off (which is the default so this does not
694 make much sense), this does not happen and an error message is
695 displayed. The state of the autoimport flag is evaluated when the
696 complete source was translated, before outputing actual code, so it is
697 <em/not/ possible to switch this feature on or off for separate sections
698 of code. The last setting is used for all symbols.
700 You should probably not use this switch because it delays error
701 messages about undefined symbols until the link stage. The cc65
702 compiler (which is supposed to produce correct assembler code in all
703 circumstances, something which is not true for most assembler
704 programmers) will insert this command to avoid importing each and every
705 routine from the runtime library.
710 .autoimport + ; Switch on auto import
714 <sect1><tt>.BLANK</tt><label id=".BLANK"><p>
716 Builtin function. The function evaluates its argument in braces and
717 yields "false" if the argument is non blank (there is an argument), and
718 "true" if there is no argument. As an example, the <tt/.IFBLANK/ statement
726 <sect1><tt>.BSS</tt><label id=".BSS"><p>
728 Switch to the BSS segment. The name of the BSS segment is always "BSS",
729 so this is a shortcut for
735 See also the <tt><ref id=".SEGMENT" name=".SEGMENT"></tt> command.
738 <sect1><tt>.BYTE</tt><label id=".BYTE"><p>
740 Define byte sized data. Must be followed by a sequence of (byte ranged)
741 expressions or strings.
746 .byte "Hello world", $0D, $00
750 <sect1><tt>.CASE</tt><label id=".CASE"><p>
752 Switch on or off case sensitivity on identifiers. The default is off
753 (that is, identifiers are case sensitive), but may be changed by the
754 -i switch on the command line.
755 The command must be followed by a '+' or '-' character to switch the
756 option on or off respectively.
761 .case - ; Identifiers are not case sensitive
765 <sect1><tt>.CODE</tt><label id=".CODE"><p>
767 Switch to the CODE segment. The name of the CODE segment is always
768 "CODE", so this is a shortcut for
774 See also the <tt><ref id=".SEGMENT" name=".SEGMENT"></tt> command.
777 <sect1><tt>.CONDES</tt><label id=".CONDES"><p>
779 Export a symbol and mark it in a special way. The linker is able to build
780 tables of all such symbols. This may be used to automatically create a list
781 of functions needed to initialize linked library modules.
783 Note: The linker has a feature to build a table of marked routines, but it
784 is your code that must call these routines, so just declaring a symbol with
785 <tt/.CONDES/ does nothing by itself.
787 All symbols are exported as an absolute (16 bit) symbol. You don't need to
788 use an additional <tt><ref id=".EXPORT" name=".EXPORT"></tt> statement, this
789 is implied by <tt/.CONDES/.
791 <tt/.CONDES/ is followed by the type, which may be <tt/constructor/,
792 <tt/destructor/ or a numeric value between 0 and 6 (where 0 is the same as
793 specifiying <tt/constructor/ and 1 is equal to specifying <tt/destructor/).
794 The <tt><ref id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt> and <tt><ref
795 id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> commands are actually shortcuts
796 for <tt/.CONDES/ with a type of <tt/constructor/ resp. <tt/destructor/.
798 After the type, an optional priority may be specified. If no priority is
799 given, the default priority of 7 is used. Be careful when assigning
800 priorities to your own module constructors so they won't interfere with the
801 ones in the cc65 library.
806 .condes ModuleInit, constructor
807 .condes ModInit, 0, 16
810 See the <tt><ref id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt> and <tt><ref
811 id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> commands and the separate section
812 <ref id="condes" name="Module constructors/destructors"> explaining the
813 feature in more detail.
816 <sect1><tt>.CONCAT</tt><label id=".CONCAT"><p>
818 Builtin function. The function allows to concatenate a list of string
819 constants separated by commas. The result is a string constant that
820 is the concatentation of all arguments. This function is most useful
821 in macros and when used together with the <tt/.STRING/ builtin function.
822 The function may be used in any case where a string constant is
828 .include .concat ("myheader", ".", "inc)
831 This is the same as the command
834 .include "myheader.inc"
838 <sect1><tt>.CONST</tt><label id=".CONST"><p>
840 Builtin function. The function evaluates its argument in braces and
841 yields "true" if the argument is a constant expression (that is, an
842 expression that yields a constant value at assembly time) and "false"
843 otherwise. As an example, the .IFCONST statement may be replaced by
850 <sect1><tt>.CONSTRUCTOR</tt><label id=".CONSTRUCTOR"><p>
852 Export a symbol and mark it as a module constructor. This may be used
853 together with the linker to build a table of constructor subroutines that
854 are called by the startup code.
856 Note: The linker has a feature to build a table of marked routines, but it
857 is your code that must call these routines, so just declaring a symbol as
858 constructor does nothing by itself.
860 A constructor is always exported as an absolute (16 bit) symbol. You don't
861 need to use an additional <tt/.export/ statement, this is implied by
862 <tt/.constructor/. It may have an optional priority that is separated by a
863 comma. If no priority is given, the default priority of 7 is used. Be
864 careful when assigning priorities to your own module constructors so they
865 won't interfere with the ones in the cc65 library.
870 .constructor ModuleInit
871 .constructor ModInit, 16
874 See the <tt><ref id=".CONDES" name=".CONDES"></tt> and <tt><ref
875 id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> commands and the separate section
876 <ref id="condes" name="Module constructors/destructors"> explaining the
877 feature in more detail.
880 <sect1><tt>.CPU</tt><label id=".CPU"><p>
882 Reading this pseudo variable will give a constant integer value that
883 tells which instruction set is currently enabled. Possible values are:
892 It may be used to replace the .IFPxx pseudo instructions or to construct
893 even more complex expressions.
898 .if (.cpu = 0) .or (.cpu = 1)
910 <sect1><tt>.DATA</tt><label id=".DATA"><p>
912 Switch to the DATA segment. The name of the DATA segment is always
913 "DATA", so this is a shortcut for
919 See also the <tt><ref id=".SEGMENT" name=".SEGMENT"></tt> command.
922 <sect1><tt>.DBYT</tt><label id=".DBYT"><p>
924 Define word sized data with the hi and lo bytes swapped (use <tt/.WORD/ to
925 create word sized data in native 65XX format). Must be followed by a
926 sequence of (word ranged) expressions.
934 This will emit the bytes
940 into the current segment in that order.
943 <sect1><tt>.DEBUGINFO</tt><label id=".DEBUGINFO"><p>
945 Switch on or off debug info generation. The default is off (that is,
946 the object file will not contain debug infos), but may be changed by the
947 -g switch on the command line.
948 The command must be followed by a '+' or '-' character to switch the
949 option on or off respectively.
954 .debuginfo + ; Generate debug info
958 <sect1><tt>.DEFINE</tt><label id=".DEFINE"><p>
960 Start a define style macro definition. The command is followed by an
961 identifier (the macro name) and optionally by a list of formal arguments
963 See section <ref id="macros" name="Macros">.
966 <sect1><tt>.DEF, .DEFINED</tt><label id=".DEFINED"><p>
968 Builtin function. The function expects an identifier as argument in braces.
969 The argument is evaluated, and the function yields "true" if the identifier
970 is a symbol that is already defined somewhere in the source file up to the
971 current position. Otherwise the function yields false. As an example, the
972 <tt><ref id=".IFDEF" name=".IFDEF"></tt> statement may be replaced by
979 <sect1><tt>.DESTRUCTOR</tt><label id=".DESTRUCTOR"><p>
981 Export a symbol and mark it as a module destructor. This may be used
982 together with the linker to build a table of destructor subroutines that
983 are called by the startup code.
985 Note: The linker has a feature to build a table of marked routines, but it
986 is your code that must call these routines, so just declaring a symbol as
987 constructor does nothing by itself.
989 A destructor is always exported as an absolute (16 bit) symbol. You don't
990 need to use an additional <tt/.export/ statement, this is implied by
991 <tt/.destructor/. It may have an optional priority that is separated by a
992 comma. If no priority is given, the default priority of 7 is used. Be
993 careful when assigning priorities to your own module destructors so they
994 won't interfere with the ones in the cc65 library.
999 .destructor ModuleDone
1000 .destructor ModDone, 16
1003 See the <tt><ref id=".CONDES" name=".CONDES"></tt> and <tt><ref
1004 id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt> commands and the separate
1005 section <ref id="condes" name="Module constructors/destructors"> explaining
1006 the feature in more detail.
1009 <sect1><tt>.DWORD</tt><label id=".DWORD"><p>
1011 Define dword sized data (4 bytes) Must be followed by a sequence of
1017 .dword $12344512, $12FA489
1021 <sect1><tt>.ELSE</tt><label id=".ELSE"><p>
1023 Conditional assembly: Reverse the current condition.
1026 <sect1><tt>.ELSEIF</tt><label id=".ELSEIF"><p>
1028 Conditional assembly: Reverse current condition and test a new one.
1031 <sect1><tt>.END</tt><label id=".END"><p>
1033 Forced end of assembly. Assembly stops at this point, even if the command
1034 is read from an include file.
1037 <sect1><tt>.ENDIF</tt><label id=".ENDIF"><p>
1039 Conditional assembly: Close a <tt><ref id=".IF" name=".IF..."></tt> or
1040 <tt><ref id=".ELSE" name=".ELSE"></tt> branch.
1043 <sect1><tt>.ENDMAC, .ENDMACRO</tt><label id=".ENDMACRO"><p>
1045 End of macro definition (see section <ref id="macros" name="Macros">).
1048 <sect1><tt>.ENDPROC</tt><label id=".ENDPROC"><p>
1050 End of local lexical level (see <tt><ref id=".PROC" name=".PROC"></tt>).
1053 <sect1><tt>.ENDREP, .ENDREPEAT</tt><label id=".ENDREPEAT"><p>
1055 End a <tt><ref id=".REPEAT" name=".REPEAT"></tt> block.
1058 <sect1><tt>.ERROR</tt><label id=".ERROR"><p>
1060 Force an assembly error. The assembler will output an error message
1061 preceeded by "User error" and will <em/not/ produce an object file.
1063 This command may be used to check for initial conditions that must be
1064 set before assembling a source file.
1074 .error "Must define foo or bar!"
1078 See also the <tt><ref id=".WARNING" name=".WARNING"></tt> and <tt><ref
1079 id=".OUT" name=".OUT"></tt> directives.
1082 <sect1><tt>.EXITMAC, .EXITMACRO</tt><label id=".EXITMACRO"><p>
1084 Abort a macro expansion immidiately. This command is often useful in
1085 recursive macros. See separate section <ref id="macros" name="Macros">.
1088 <sect1><tt>.EXPORT</tt><label id=".EXPORT"><p>
1090 Make symbols accessible from other modules. Must be followed by a comma
1091 separated list of symbols to export.
1099 See: <tt><ref id=".EXPORTZP" name=".EXPORTZP"></tt>
1102 <sect1><tt>.EXPORTZP</tt><label id=".EXPORTZP"><p>
1104 Make symbols accessible from other modules. Must be followed by a comma
1105 separated list of symbols to export. The exported symbols are explicitly
1106 marked as zero page symols.
1114 See: <tt><ref id=".EXPORT" name=".EXPORT"></tt>
1117 <sect1><tt>.FARADDR</tt><label id=".FARADDR"><p>
1119 Define far (24 bit) address data. The command must be followed by a
1120 sequence of (not necessarily constant) expressions.
1125 .faraddr DrawCircle, DrawRectangle, DrawHexagon
1128 See: <tt><ref id=".ADDR" name=".ADDR"></tt>
1131 <sect1><tt>.FEATURE</tt><label id=".FEATURE"><p>
1133 This directive may be used to enable one or more compatibility features
1134 of the assembler. While the use of <tt/.FEATURE/ should be avoided when
1135 possible, it may be useful when porting sources written for other
1136 assemblers. There is no way to switch a feature off, once you have
1137 enabled it, so using
1143 will enable the feature until end of assembly is reached.
1145 The following features are available:
1149 <tag><tt>dollar_is_pc</tt></tag>
1151 The dollar sign may be used as an alias for the star (`*'), which
1152 gives the value of the current PC in expressions.
1153 Note: Assignment to the pseudo variable is not allowed.
1155 <tag><tt>labels_without_colons</tt></tag>
1157 Allow labels without a trailing colon. These labels are only accepted,
1158 if they start at the beginning of a line (no leading white space).
1160 <tag><tt>loose_string_term</tt></tag>
1162 Accept single quotes as well as double quotes as terminators for string
1165 <tag><tt>loose_char_term</tt></tag>
1167 Accept single quotes as well as double quotes as terminators for char
1170 <tag><tt>at_in_identifiers</tt></tag>
1172 Accept the at character (`@') as a valid character in identifiers. The
1173 at character is not allowed to start an identifier, even with this
1176 <tag><tt>dollar_in_identifiers</tt></tag>
1178 Accept the dollar sign (`$') as a valid character in identifiers. The
1179 at character is not allowed to start an identifier, even with this
1182 <tag><tt>pc_assignment</tt></tag>
1184 Allow assignments to the PC symbol (`*' or `$' if <tt/dollar_is_pc/
1185 is enabled). Such an assignment is handled identical to the <tt><ref
1186 id=".ORG" name=".ORG"></tt> command (which is usually not needed, so just
1187 removing the lines with the assignments may also be an option when porting
1188 code written for older assemblers).
1192 It is also possible to specify features on the command line using the
1193 <tt><ref id="option--feature" name="--feature"></tt> command line option.
1194 This is useful when translating sources written for older assemblers, when
1195 you don't want to change the source code.
1197 As an example, to translate sources written for Andre Fachats xa65
1198 assembler, the features
1201 labels_without_colons, pc_assignment, loose_char_term
1204 may be helpful. They do not make ca65 completely compatible, so you may not
1205 be able to translate the sources without changes, even when enabling these
1206 features. However, I have found several sources that translate without
1207 problems when enabling these features on the command line.
1210 <sect1><tt>.FILEOPT, .FOPT</tt><label id=".FOPT"><p>
1212 Insert an option string into the object file. There are two forms of
1213 this command, one specifies the option by a keyword, the second
1214 specifies it as a number. Since usage of the second one needs knowledge
1215 of the internal encoding, its use is not recommended and I will only
1216 describe the first form here.
1218 The command is followed by one of the keywords
1226 a comma and a string. The option is written into the object file
1227 together with the string value. This is currently unidirectional and
1228 there is no way to actually use these options once they are in the
1234 .fileopt comment, "Code stolen from my brother"
1235 .fileopt compiler, "BASIC 2.0"
1236 .fopt author, "J. R. User"
1240 <sect1><tt>.GLOBAL</tt><label id=".GLOBAL"><p>
1242 Declare symbols as global. Must be followed by a comma separated list of
1243 symbols to declare. Symbols from the list, that are defined somewhere in the
1244 source, are exported, all others are imported. Additional <tt><ref
1245 id=".IMPORT" name=".IMPORT"></tt> or <tt><ref id=".EXPORT"
1246 name=".EXPORT"></tt> commands for the same symbol are allowed.
1255 <sect1><tt>.GLOBALZP</tt><label id=".GLOBALZP"><p>
1257 Declare symbols as global. Must be followed by a comma separated list of
1258 symbols to declare. Symbols from the list, that are defined somewhere in the
1259 source, are exported, all others are imported. Additional <tt><ref
1260 id=".IMPORTZP" name=".IMPORTZP"></tt> or <tt><ref id=".EXPORTZP"
1261 name=".EXPORTZP"></tt> commands for the same symbol are allowed. The symbols
1262 in the list are explicitly marked as zero page symols.
1271 <sect1><tt>.I16</tt><label id=".I16"><p>
1273 Valid only in 65816 mode. Switch the index registers to 16 bit.
1275 Note: This command will not emit any code, it will tell the assembler to
1276 create 16 bit operands for immediate operands.
1278 See also the <tt><ref id=".I8" name=".I8"></tt> and <tt><ref id=".SMART"
1279 name=".SMART"></tt> commands.
1282 <sect1><tt>.I8</tt><label id=".I8"><p>
1284 Valid only in 65816 mode. Switch the index registers to 8 bit.
1286 Note: This command will not emit any code, it will tell the assembler to
1287 create 8 bit operands for immediate operands.
1289 See also the <tt><ref id=".I16" name=".I16"></tt> and <tt><ref id=".SMART"
1290 name=".SMART"></tt> commands.
1293 <sect1><tt>.IF</tt><label id=".IF"><p>
1295 Conditional assembly: Evalute an expression and switch assembler output
1296 on or off depending on the expression. The expression must be a constant
1297 expression, that is, all operands must be defined.
1299 A expression value of zero evaluates to FALSE, any other value evaluates
1303 <sect1><tt>.IFBLANK</tt><label id=".IFBLANK"><p>
1305 Conditional assembly: Check if there are any remaining tokens in this line,
1306 and evaluate to FALSE if this is the case, and to TRUE otherwise. If the
1307 condition is not true, further lines are not assembled until an <tt><ref
1308 id=".ELSE" name=".ESLE"></tt>, <tt><ref id=".ELSEIF" name=".ELSEIF"></tt> or
1309 <tt><ref id=".ENDIF" name=".ENDIF"></tt> directive.
1311 This command is often used to check if a macro parameter was given. Since an
1312 empty macro parameter will evaluate to nothing, the condition will evaluate
1313 to FALSE if an empty parameter was given.
1327 See also: <tt><ref id=".BLANK" name=".BLANK"></tt>
1330 <sect1><tt>.IFCONST</tt><label id=".IFCONST"><p>
1332 Conditional assembly: Evaluate an expression and switch assembler output
1333 on or off depending on the constness of the expression.
1335 A const expression evaluates to to TRUE, a non const expression (one
1336 containing an imported or currently undefined symbol) evaluates to
1339 See also: <tt><ref id=".CONST" name=".CONST"></tt>
1342 <sect1><tt>.IFDEF</tt><label id=".IFDEF"><p>
1344 Conditional assembly: Check if a symbol is defined. Must be followed by
1345 a symbol name. The condition is true if the the given symbol is already
1346 defined, and false otherwise.
1348 See also: <tt><ref id=".DEFINED" name=".DEFINED"></tt>
1351 <sect1><tt>.IFNBLANK</tt><label id=".IFNBLANK"><p>
1353 Conditional assembly: Check if there are any remaining tokens in this line,
1354 and evaluate to TRUE if this is the case, and to FALSE otherwise. If the
1355 condition is not true, further lines are not assembled until an <tt><ref
1356 id=".ELSE" name=".ELSE"></tt>, <tt><ref id=".ELSEIF" name=".ELSEIF"></tt> or
1357 <tt><ref id=".ENDIF" name=".ENDIF"></tt> directive.
1359 This command is often used to check if a macro parameter was given.
1360 Since an empty macro parameter will evaluate to nothing, the condition
1361 will evaluate to FALSE if an empty parameter was given.
1374 See also: <tt><ref id=".BLANK" name=".BLANK"></tt>
1377 <sect1><tt>.IFNDEF</tt><label id=".IFNDEF"><p>
1379 Conditional assembly: Check if a symbol is defined. Must be followed by
1380 a symbol name. The condition is true if the the given symbol is not
1381 defined, and false otherwise.
1383 See also: <tt><ref id=".DEFINED" name=".DEFINED"></tt>
1386 <sect1><tt>.IFNREF</tt><label id=".IFNREF"><p>
1388 Conditional assembly: Check if a symbol is referenced. Must be followed
1389 by a symbol name. The condition is true if if the the given symbol was
1390 not referenced before, and false otherwise.
1392 See also: <tt><ref id=".REFERENCED" name=".REFERENCED"></tt>
1395 <sect1><tt>.IFP02</tt><label id=".IFP02"><p>
1397 Conditional assembly: Check if the assembler is currently in 6502 mode
1398 (see <tt><ref id=".P02" name=".P02"></tt> command).
1401 <sect1><tt>.IFP816</tt><label id=".IFP816"><p>
1403 Conditional assembly: Check if the assembler is currently in 65816 mode
1404 (see <tt><ref id=".P816" name=".P816"></tt> command).
1407 <sect1><tt>.IFPC02</tt><label id=".IFPC02"><p>
1409 Conditional assembly: Check if the assembler is currently in 65C02 mode
1410 (see <tt><ref id=".PC02" name=".PC02"></tt> command).
1413 <sect1><tt>.IFREF</tt><label id=".IFREF"><p>
1415 Conditional assembly: Check if a symbol is referenced. Must be followed
1416 by a symbol name. The condition is true if if the the given symbol was
1417 referenced before, and false otherwise.
1419 This command may be used to build subroutine libraries in include files
1420 (you may use separate object modules for this purpose too).
1425 .ifref ToHex ; If someone used this subroutine
1426 ToHex: tay ; Define subroutine
1432 See also: <tt><ref id=".REFERENCED" name=".REFERENCED"></tt>
1435 <sect1><tt>.IMPORT</tt><label id=".IMPORT"><p>
1437 Import a symbol from another module. The command is followed by a comma
1438 separated list of symbols to import.
1446 See: <tt><ref id=".IMPORTZP" name=".IMPORTZP"></tt>
1449 <sect1><tt>.IMPORTZP</tt><label id=".IMPORTZP"><p>
1451 Import a symbol from another module. The command is followed by a comma
1452 separated list of symbols to import. The symbols are explicitly imported
1453 as zero page symbols (that is, symbols with values in byte range).
1461 See: <tt><ref id=".IMPORT" name=".IMPORT"></tt>
1464 <sect1><tt>.INCBIN</tt><label id=".INCBIN"><p>
1466 Include a file as binary data. The command expects a string argument
1467 that is the name of a file to include literally in the current segment.
1468 In addition to that, a start offset and a size value may be specified,
1469 separated by commas. If no size is specified, all of the file from the
1470 start offset to end-of-file is used. If no start position is specified
1471 either, zero is assume (which means that the whole file is inserted).
1476 ; Include whole file
1477 .incbin "sprites.dat"
1479 ; Include file starting at offset 256
1480 .incbin "music.dat", $100
1482 ; Read 100 bytes starting at offset 200
1483 .incbin "graphics.dat", 200, 100
1487 <sect1><tt>.INCLUDE</tt><label id=".INCLUDE"><p>
1489 Include another file. Include files may be nested up to a depth of 16.
1498 <sect1><tt>.LEFT</tt><label id=".LEFT"><p>
1500 Builtin function. Extracts the left part of a given token list.
1505 .LEFT (<int expr>, <token list>)
1508 The first integer expression gives the number of tokens to extract from
1509 the token list. The second argument is the token list itself.
1513 To check in a macro if the given argument has a '#' as first token
1514 (immidiate addressing mode), use something like this:
1519 .if (.match (.left (1, arg), #))
1521 ; ldax called with immidiate operand
1529 See also the <tt><ref id=".MID" name=".MID"></tt> and <tt><ref id=".RIGHT"
1530 name=".RIGHT"></tt> builtin functions.
1533 <sect1><tt>.LINECONT</tt><label id=".LINECONT"><p>
1535 Switch on or off line continuations using the backslash character
1536 before a newline. The option is off by default.
1537 Note: Line continuations do not work in a comment. A backslash at the
1538 end of a comment is treated as part of the comment and does not trigger
1540 The command must be followed by a '+' or '-' character to switch the
1541 option on or off respectively.
1546 .linecont + ; Allow line continuations
1549 #$20 ; This is legal now
1553 <sect1><tt>.LIST</tt><label id=".LIST"><p>
1555 Enable output to the listing. The command must be followed by a boolean
1556 switch ("on", "off", "+" or "-") and will enable or disable listing
1558 The option has no effect if the listing is not enabled by the command line
1559 switch -l. If -l is used, an internal counter is set to 1. Lines are output
1560 to the listing file, if the counter is greater than zero, and suppressed if
1561 the counter is zero. Each use of <tt/.LIST/ will increment or decrement the
1567 .list on ; Enable listing output
1571 <sect1><tt>.LISTBYTES</tt><label id=".LISTBYTES"><p>
1573 Set, how many bytes are shown in the listing for one source line. The
1574 default is 12, so the listing will show only the first 12 bytes for any
1575 source line that generates more than 12 bytes of code or data.
1576 The directive needs an argument, which is either "unlimited", or an
1577 integer constant in the range 4..255.
1582 .listbytes unlimited ; List all bytes
1583 .listbytes 12 ; List the first 12 bytes
1584 .incbin "data.bin" ; Include large binary file
1588 <sect1><tt>.LOCAL</tt><label id=".LOCAL"><p>
1590 This command may only be used inside a macro definition. It declares a
1591 list of identifiers as local to the macro expansion.
1593 A problem when using macros are labels: Since they don't change their name,
1594 you get a "duplicate symbol" error if the macro is expanded the second time.
1595 Labels declared with <tt><ref id=".LOCAL" name=".LOCAL"></tt> have their
1596 name mapped to an internal unique name (<tt/___ABCD__/) with each macro
1599 Some other assemblers start a new lexical block inside a macro expansion.
1600 This has some drawbacks however, since that will not allow <em/any/ symbol
1601 to be visible outside a macro, a feature that is sometimes useful. The
1602 <tt><ref id=".LOCAL" name=".LOCAL"></tt> command is in my eyes a better way
1603 to address the problem.
1605 You get an error when using <tt><ref id=".LOCAL" name=".LOCAL"></tt> outside
1609 <sect1><tt>.LOCALCHAR</tt><label id=".LOCALCHAR"><p>
1611 Defines the character that start "cheap" local labels. You may use one
1612 of '@' and '?' as start character. The default is '@'.
1614 Cheap local labels are labels that are visible only between two non
1615 cheap labels. This way you can reuse identifiers like "<tt/loop/" without
1616 using explicit lexical nesting.
1623 Clear: lda #$00 ; Global label
1624 ?Loop: sta Mem,y ; Local label
1628 Sub: ... ; New global label
1629 bne ?Loop ; ERROR: Unknown identifier!
1633 <sect1><tt>.MACPACK</tt><label id=".MACPACK"><p>
1635 Insert a predefined macro package. The command is followed by an
1636 identifier specifying the macro package to insert. Available macro
1640 generic Defines generic macros like add and sub.
1641 longbranch Defines conditional long jump macros.
1644 Including a macro package twice, or including a macro package that
1645 redefines already existing macros will lead to an error.
1650 .macpack longbranch ; Include macro package
1652 cmp #$20 ; Set condition codes
1653 jne Label ; Jump long on condition
1656 Macro packages are explained in more detail in section <ref
1657 id="macropackages" name="Macro packages">).
1660 <sect1><tt>.MAC, .MACRO</tt><label id=".MAC"><p>
1662 Start a classic macro definition. The command is followed by an identifier
1663 (the macro name) and optionally by a comma separated list of identifiers
1664 that are macro parameters.
1666 See section <ref id="macros" name="Macros">).
1669 <sect1><tt>.MATCH</tt><label id=".MATCH"><p>
1671 Builtin function. Matches two token lists against each other. This is
1672 most useful within macros, since macros are not stored as strings, but
1678 .MATCH(<token list #1>, <token list #2>)
1681 Both token list may contain arbitrary tokens with the exception of the
1682 terminator token (comma resp. right parenthesis) and
1689 Often a macro parameter is used for any of the token lists.
1691 Please note that the function does only compare tokens, not token
1692 attributes. So any number is equal to any other number, regardless of the
1693 actual value. The same is true for strings. If you need to compare tokens
1694 <em/and/ token attributes, use the <tt><ref id=".XMATCH"
1695 name=".XMATCH"></tt> function.
1699 Assume the macro <tt/ASR/, that will shift right the accumulator by one,
1700 while honoring the sign bit. The builtin processor instructions will allow
1701 an optional "A" for accu addressing for instructions like <tt/ROL/ and
1702 <tt/ROR/. We will use the <tt><ref id=".MATCH" name=".MATCH"></tt> function
1703 to check for this and print and error for invalid calls.
1708 .if (.not .blank(arg)) .and (.not .match (arg, a))
1709 .error "Syntax error"
1712 cmp #$80 ; Bit 7 into carry
1713 lsr a ; Shit carry into bit 7
1718 The macro will only accept no arguments, or one argument that must be the
1719 reserved keyword "A".
1721 See: <tt><ref id=".XMATCH" name=".XMATCH"></tt>
1724 <sect1><tt>.MID</tt><label id=".MID"><p>
1726 Builtin function. Takes a starting index, a count and a token list as
1727 arguments. Will return part of the token list.
1732 .MID (<int expr>, <int expr>, <token list>)
1735 The first integer expression gives the starting token in the list (the
1736 first token has index 0). The second integer expression gives the number
1737 of tokens to extract from the token list. The third argument is the
1742 To check in a macro if the given argument has a '<tt/#/' as first token
1743 (immidiate addressing mode), use something like this:
1748 .if (.match (.mid (0, 1, arg), #))
1750 ; ldax called with immidiate operand
1758 See also the <tt><ref id=".LEFT" name=".LEFT"></tt> and <tt><ref id=".RIGHT"
1759 name=".RIGHT"></tt> builtin functions.
1762 <sect1><tt>.ORG</tt><label id=".ORG"><p>
1764 Start a section of absolute code. The command is followed by a constant
1765 expression that gives the new PC counter location for which the code is
1766 assembled. Use <tt><ref id=".RELOC" name=".RELOC"></tt> to switch back to
1769 Please note that you <em/do not need/ this command in most cases. Placing
1770 code at a specific address is the job of the linker, not the assembler, so
1771 there is usually no reason to assemble code to a specific address.
1773 You may not switch segments while inside a section of absolute code.
1778 .org $7FF ; Emit code starting at $7FF
1782 <sect1><tt>.OUT</tt><label id=".OUT"><p>
1784 Output a string to the console without producing an error. This command
1785 is similiar to <tt/.ERROR/, however, it does not force an assembler error
1786 that prevents the creation of an object file.
1791 .out "This code was written by the codebuster(tm)"
1794 See also the <tt><ref id=".WARNING" name=".WARNING"></tt> and <tt><ref
1795 id=".ERROR" name=".ERROR"></tt> directives.
1798 <sect1><tt>.P02</tt><label id=".P02"><p>
1800 Enable the 6502 instruction set, disable 65C02 and 65816 instructions.
1801 This is the default if not overridden by the <tt/--cpu/ command line
1804 See: <tt><ref id=".PC02" name=".PC02"></tt> and <tt><ref id=".P816"
1808 <sect1><tt>.P816</tt><label id=".P816"><p>
1810 Enable the 65816 instruction set. This is a superset of the 65C02 and
1811 6502 instruction sets.
1813 See: <tt><ref id=".P02" name=".P02"></tt> and <tt><ref id=".PC02"
1817 <sect1><tt>.PAGELEN, .PAGELENGTH</tt><label id=".PAGELENGTH"><p>
1819 Set the page length for the listing. Must be followed by an integer
1820 constant. The value may be "unlimited", or in the range 32 to 127. The
1821 statement has no effect if no listing is generated. The default value is -1
1822 (unlimited) but may be overridden by the <tt/--pagelength/ command line
1823 option. Beware: Since ca65 is a one pass assembler, the listing is generated
1824 after assembly is complete, you cannot use multiple line lengths with one
1825 source. Instead, the value set with the last <tt/.PAGELENGTH/ is used.
1830 .pagelength 66 ; Use 66 lines per listing page
1832 .pagelength unlimited ; Unlimited page length
1836 <sect1><tt>.PARAMCOUNT</tt><label id=".PARAMCOUNT"><p>
1838 This builtin pseudo variable is only available in macros. It is replaced by
1839 the actual number of parameters that were given in the macro invocation.
1844 .macro foo arg1, arg2, arg3
1845 .if .paramcount <> 3
1846 .error "Too few parameters for macro foo"
1852 See section <ref id="macros" name="Macros">.
1855 <sect1><tt>.PC02</tt><label id=".PC02"><p>
1857 Enable the 65C02 instructions set. This instruction set includes all
1860 See: <tt><ref id=".P02" name=".P02"></tt> and <tt><ref id=".P816"
1864 <sect1><tt>.PROC</tt><label id=".PROC"><p>
1866 Start a nested lexical level. All new symbols from now on are in the local
1867 lexical level and are not accessible from outside. Symbols defined outside
1868 this local level may be accessed as long as their names are not used for new
1869 symbols inside the level. Symbols names in other lexical levels do not
1870 clash, so you may use the same names for identifiers. The lexical level ends
1871 when the <tt><ref id=".ENDPROC" name=".ENDPROC"></tt> command is read.
1872 Lexical levels may be nested up to a depth of 16.
1874 The command may be followed by an identifier, in this case the
1875 identifier is declared in the outer level as a label having the value of
1876 the program counter at the start of the lexical level.
1878 Note: Macro names are always in the global level and in a separate name
1879 space. There is no special reason for this, it's just that I've never
1880 had any need for local macro definitions.
1885 .proc Clear ; Define Clear subroutine, start new level
1887 L1: sta Mem,y ; L1 is local and does not cause a
1888 ; duplicate symbol error if used in other
1891 bne L1 ; Reference local symbol
1893 .endproc ; Leave lexical level
1896 See: <tt><ref id=".ENDPROC" name=".ENDPROC"></tt>
1899 <sect1><tt>.REF, .REFERENCED</tt><label id=".REFERENCED"><p>
1901 Builtin function. The function expects an identifier as argument in braces.
1902 The argument is evaluated, and the function yields "true" if the identifier
1903 is a symbol that has already been referenced somewhere in the source file up
1904 to the current position. Otherwise the function yields false. As an example,
1905 the <tt><ref id=".IFREF" name=".IFREF"></tt> statement may be replaced by
1911 See: <tt><ref id=".DEFINED" name=".DEFINED"></tt>
1914 <sect1><tt>.REPEAT</tt><label id=".REPEAT"><p>
1916 Repeat all commands between <tt/.REPEAT/ and <tt><ref id=".ENDREPEAT"
1917 name=".ENDREPEAT"></tt> constant number of times. The command is followed by
1918 a constant expression that tells how many times the commands in the body
1919 should get repeated. Optionally, a comma and an identifier may be specified.
1920 If this identifier is found in the body of the repeat statement, it is
1921 replaced by the current repeat count (starting with zero for the first time
1922 the body is repeated).
1924 <tt/.REPEAT/ statements may be nested. If you use the same repeat count
1925 identifier for a nested <tt/.REPEAT/ statement, the one from the inner
1926 level will be used, not the one from the outer level.
1930 The following macro will emit a string that is "encrypted" in that all
1931 characters of the string are XORed by the value $55.
1935 .repeat .strlen(Arg), I
1936 .byte .strat(Arg, I) .xor $55
1941 See: <tt><ref id=".ENDREPEAT" name=".ENDREPEAT"></tt>
1944 <sect1><tt>.RELOC</tt><label id=".RELOC"><p>
1946 Switch back to relocatable mode. See the <tt><ref id=".ORG"
1947 name=".ORG"></tt> command.
1950 <sect1><tt>.RES</tt><label id=".RES"><p>
1952 Reserve storage. The command is followed by one or two constant
1953 expressions. The first one is mandatory and defines, how many bytes of
1954 storage should be defined. The second, optional expression must by a
1955 constant byte value that will be used as value of the data. If there
1956 is no fill value given, the linker will use the value defined in the
1957 linker configuration file (default: zero).
1962 ; Reserve 12 bytes of memory with value $AA
1967 <sect1><tt>.RIGHT</tt><label id=".RIGHT"><p>
1969 Builtin function. Extracts the right part of a given token list.
1974 .RIGHT (<int expr>, <token list>)
1977 The first integer expression gives the number of tokens to extract from
1978 the token list. The second argument is the token list itself.
1980 See also the <tt><ref id=".LEFT" name=".LEFT"></tt> and <tt><ref id=".MID"
1981 name=".MID"></tt> builtin functions.
1984 <sect1><tt>.RODATA</tt><label id=".RODATA"><p>
1986 Switch to the RODATA segment. The name of the RODATA segment is always
1987 "RODATA", so this is a shortcut for
1993 The RODATA segment is a segment that is used by the compiler for
1994 readonly data like string constants.
1996 See also the <tt><ref id=".SEGMENT" name=".SEGMENT"></tt> command.
1999 <sect1><tt>.SEGMENT</tt><label id=".SEGMENT"><p>
2001 Switch to another segment. Code and data is always emitted into a
2002 segment, that is, a named section of data. The default segment is
2003 "CODE". There may be up to 254 different segments per object file
2004 (and up to 65534 per executable). There are shortcut commands for
2005 the most common segments ("CODE", "DATA" and "BSS").
2007 The command is followed by a string containing the segment name (there
2008 are some constraints for the name - as a rule of thumb use only those
2009 segment names that would also be valid identifiers). There may also be
2010 an optional attribute separated by a comma. Valid attributes are
2011 "<tt/zeropage/" and "<tt/absolute/".
2013 When specifying a segment for the first time, "absolute" is the
2014 default. For all other uses, the attribute specified the first time
2017 "absolute" means that this is a segment with absolute addressing. That
2018 is, the segment will reside somewhere in core memory outside the zero
2019 page. "zeropage" means the opposite: The segment will be placed in the
2020 zero page and direct (short) addressing is possible for data in this
2023 Beware: Only labels in a segment with the zeropage attribute are marked
2024 as reachable by short addressing. The `*' (PC counter) operator will
2025 work as in other segments and will create absolute variable values.
2030 .segment "ROM2" ; Switch to ROM2 segment
2031 .segment "ZP2", zeropage ; New direct segment
2032 .segment "ZP2" ; Ok, will use last attribute
2033 .segment "ZP2", absolute ; Error, redecl mismatch
2036 See: <tt><ref id=".BSS" name=".BSS"></tt>, <tt><ref id=".CODE"
2037 name=".CODE"></tt>, <tt><ref id=".DATA" name=".DATA"></tt> and <tt><ref
2038 id=".RODATA" name=".RODATA"></tt>
2041 <sect1><tt>.SMART</tt><label id=".SMART"><p>
2043 Switch on or off smart mode. The command must be followed by a '+' or
2044 '-' character to switch the option on or off respectively. The default
2045 is off (that is, the assembler doesn't try to be smart), but this
2046 default may be changed by the -s switch on the command line.
2048 In smart mode the assembler will track usage of the <tt/REP/ and <tt/SEP/
2049 instructions in 65816 mode and update the operand sizes accordingly. If
2050 the operand of such an instruction cannot be evaluated by the assembler
2051 (for example, because the operand is an imported symbol), a warning is
2052 issued. Beware: Since the assembler cannot trace the execution flow this
2053 may lead to false results in some cases. If in doubt, use the <tt/.Inn/ and
2054 <tt/.Ann/ instructions to tell the assembler about the current settings.
2060 .smart - ; Stop being smart
2064 <sect1><tt>.STRAT</tt><label id=".STRAT"><p>
2066 Builtin function. The function accepts a string and an index as
2067 arguments and returns the value of the character at the given position
2068 as an integer value. The index is zero based.
2074 ; Check if the argument string starts with '#'
2075 .if (.strat (Arg, 0) = '#')
2082 <sect1><tt>.STRING</tt><label id=".STRING"><p>
2084 Builtin function. The function accepts an argument in braces and converts
2085 this argument into a string constant. The argument may be an identifier, or
2086 a constant numeric value.
2088 Since you can use a string in the first place, the use of the function may
2089 not be obvious. However, it is useful in macros, or more complex setups.
2094 ; Emulate other assemblers:
2096 .segment .string(name)
2101 <sect1><tt>.STRLEN</tt><label id=".STRLEN"><p>
2103 Builtin function. The function accepts a string argument in braces and
2104 eveluates to the length of the string.
2108 The following macro encodes a string as a pascal style string with
2109 a leading length byte.
2113 .byte .strlen(Arg), Arg
2118 <sect1><tt>.TCOUNT</tt><label id=".TCOUNT"><p>
2120 Builtin function. The function accepts a token list in braces. The
2121 function result is the number of tokens given as argument.
2125 The <tt/ldax/ macro accepts the '#' token to denote immidiate addressing (as
2126 with the normal 6502 instructions). To translate it into two separate 8 bit
2127 load instructions, the '#' token has to get stripped from the argument:
2131 .if (.match (.mid (0, 1, arg), #))
2132 ; ldax called with immidiate operand
2133 lda #<(.right (.tcount (arg)-1, arg))
2134 ldx #>(.right (.tcount (arg)-1, arg))
2142 <sect1><tt>.WARNING</tt><label id=".WARNING"><p>
2144 Force an assembly warning. The assembler will output a warning message
2145 preceeded by "User warning". This warning will always be output, even if
2146 other warnings are disabled with the <tt><ref id="option-W" name="-W0"></tt>
2147 command line option.
2149 This command may be used to output possible problems when assembling
2158 .warning "Forward jump in jne, cannot optimize!"
2168 See also the <tt><ref id=".ERROR" name=".ERROR"></tt> and <tt><ref id=".OUT"
2169 name=".OUT"></tt> directives.
2172 <sect1><tt>.WORD</tt><label id=".WORD"><p>
2174 Define word sized data. Must be followed by a sequence of (word ranged,
2175 but not necessarily constant) expressions.
2180 .word $0D00, $AF13, _Clear
2184 <sect1><tt>.XMATCH</tt><label id=".XMATCH"><p>
2186 Builtin function. Matches two token lists against each other. This is
2187 most useful within macros, since macros are not stored as strings, but
2193 .XMATCH(<token list #1>, <token list #2>)
2196 Both token list may contain arbitrary tokens with the exception of the
2197 terminator token (comma resp. right parenthesis) and
2204 Often a macro parameter is used for any of the token lists.
2206 The function compares tokens <em/and/ token values. If you need a function
2207 that just compares the type of tokens, have a look at the <tt><ref
2208 id=".MATCH" name=".MATCH"></tt> function.
2210 See: <tt><ref id=".MATCH" name=".MATCH"></tt>
2213 <sect1><tt>.ZEROPAGE</tt><label id=".ZEROPAGE"><p>
2215 Switch to the ZEROPAGE segment and mark it as direct (zeropage) segment.
2216 The name of the ZEROPAGE segment is always "ZEROPAGE", so this is a
2220 .segment "ZEROPAGE", zeropage
2223 Because of the "zeropage" attribute, labels declared in this segment are
2224 addressed using direct addressing mode if possible. You <em/must/ instruct
2225 the linker to place this segment somewhere in the address range 0..$FF
2226 otherwise you will get errors.
2228 See: <tt><ref id=".SEGMENT" name=".SEGMENT"></tt>
2232 <sect>Macros<label id="macros"><p>
2235 <sect1>Introduction<p>
2237 Macros may be thought of as "parametrized super instructions". Macros are
2238 sequences of tokens that have a name. If that name is used in the source
2239 file, the macro is "expanded", that is, it is replaced by the tokens that
2240 were specified when the macro was defined.
2243 <sect1>Macros without parameters<p>
2245 In it's simplest form, a macro does not have parameters. Here's an
2249 .macro asr ; Arithmetic shift right
2250 cmp #$80 ; Put bit 7 into carry
2251 ror ; Rotate right with carry
2255 The macro above consists of two real instructions, that are inserted into
2256 the code, whenever the macro is expanded. Macro expansion is simply done
2257 by using the name, like this:
2266 <sect1>Parametrized macros<p>
2268 When using macro parameters, macros can be even more useful:
2282 When calling the macro, you may give a parameter, and each occurence of
2283 the name "addr" in the macro definition will be replaced by the given
2302 A macro may have more than one parameter, in this case, the parameters
2303 are separated by commas. You are free to give less parameters than the
2304 macro actually takes in the definition. You may also leave intermediate
2305 parameters empty. Empty parameters are replaced by empty space (that is,
2306 they are removed when the macro is exanded). If you have a look at our
2307 macro definition above, you will see, that replacing the "addr" parameter
2308 by nothing will lead to wrong code in most lines. To help you, writing
2309 macros with a variable parameter list, there are some control commands:
2311 <tt><ref id=".IFBLANK" name=".IFBLANK"></tt> tests the rest of the line and
2312 returns true, if there are any tokens on the remainder of the line. Since
2313 empty parameters are replaced by nothing, this may be used to test if a given
2314 parameter is empty. <tt><ref id=".IFNBLANK" name=".IFNBLANK"></tt> tests the
2317 Look at this example:
2320 .macro ldaxy a, x, y
2333 This macro may be called as follows:
2336 ldaxy 1, 2, 3 ; Load all three registers
2338 ldaxy 1, , 3 ; Load only a and y
2340 ldaxy , , 3 ; Load y only
2343 There's another helper command for determining, which macro parameters are
2344 valid: <tt><ref id=".PARAMCOUNT" name=".PARAMCOUNT"></tt> This command is
2345 replaced by the parameter count given, <em/including/ intermediate empty macro
2349 ldaxy 1 ; .PARAMCOUNT = 1
2350 ldaxy 1,,3 ; .PARAMCOUNT = 3
2351 ldaxy 1,2 ; .PARAMCOUNT = 2
2352 ldaxy 1, ; .PARAMCOUNT = 2
2353 ldaxy 1,2,3 ; .PARAMCOUNT = 3
2357 <sect1>Recursive macros<p>
2359 Macros may be used recursively:
2362 .macro push r1, r2, r3
2371 There's also a special macro to help writing recursive macros: <tt><ref
2372 id=".EXITMACRO" name=".EXITMACRO"></tt> This command will stop macro expansion
2376 .macro push r1, r2, r3, r4, r5, r6, r7
2378 ; First parameter is empty
2384 push r2, r3, r4, r5, r6, r7
2388 When expanding this macro, the expansion will push all given parameters
2389 until an empty one is encountered. The macro may be called like this:
2392 push $20, $21, $32 ; Push 3 ZP locations
2393 push $21 ; Push one ZP location
2397 <sect1>Local symbols inside macros<p>
2399 Now, with recursive macros, <tt><ref id=".IFBLANK" name=".IFBLANK"></tt> and
2400 <tt><ref id=".PARAMCOUNT" name=".PARAMCOUNT"></tt>, what else do you need?
2401 Have a look at the inc16 macro above. Here is it again:
2415 If you have a closer look at the code, you will notice, that it could be
2416 written more efficiently, like this:
2430 But imagine what happens, if you use this macro twice? Since the label
2431 "Skip" has the same name both times, you get a "duplicate symbol" error.
2432 Without a way to circumvent this problem, macros are not as useful, as
2433 they could be. One solution is, to start a new lexical block inside the
2450 Now the label is local to the block and not visible outside. However,
2451 sometimes you want a label inside the macro to be visible outside. To make
2452 that possible, there's a new command that's only usable inside a macro
2453 definition: <tt><ref id=".LOCAL" name=".LOCAL"></tt>. <tt/.LOCAL/ declares one
2454 or more symbols as local to the macro expansion. The names of local variables
2455 are replaced by a unique name in each separate macro expansion. So we could
2456 also solve the problem above by using <tt/.LOCAL/:
2460 .local Skip ; Make Skip a local symbol
2467 Skip: ; Not visible outside
2472 <sect1>C style macros<p>
2474 Starting with version 2.5 of the assembler, there is a second macro type
2475 available: C style macros using the <tt/.DEFINE/ directive. These macros are
2476 similar to the classic macro type speified above, but behaviour is sometimes
2481 <item> Macros defined with <tt><ref id=".DEFINE" name=".DEFINE"></tt> may not
2482 span more than a line. You may use line continuation (see <tt><ref
2483 id=".LINECONT" name=".LINECONT"></tt>) to spread the definition over
2484 more than one line for increased readability, but the macro itself
2485 may not contain an end-of-line token.
2487 <item> Macros defined with <tt><ref id=".DEFINE" name=".DEFINE"></tt> share
2488 the name space with classic macros, but they are detected and replaced
2489 at the scanner level. While classic macros may be used in every place,
2490 where a mnemonic or other directive is allowed, <tt><ref id=".DEFINE"
2491 name=".DEFINE"></tt> style macros are allowed anywhere in a line. So
2492 they are more versatile in some situations.
2494 <item> <tt><ref id=".DEFINE" name=".DEFINE"></tt> style macros may take
2495 parameters. While classic macros may have empty parameters, this is
2496 not true for <tt><ref id=".DEFINE" name=".DEFINE"></tt> style macros.
2497 For this macro type, the number of actual parameters must match
2498 exactly the number of formal parameters.
2500 To make this possible, formal parameters are enclosed in braces when
2501 defining the macro. If there are no parameters, the empty braces may
2504 <item> Since <tt><ref id=".DEFINE" name=".DEFINE"></tt> style macros may not
2505 contain end-of-line tokens, there are things that cannot be done. They
2506 may not contain several processor instructions for example. So, while
2507 some things may be done with both macro types, each type has special
2508 usages. The types complement each other.
2512 Let's look at a few examples to make the advantages and disadvantages
2515 To emulate assemblers that use "<tt/EQU/" instead of "<tt/=/" you may use the
2516 following <tt/.DEFINE/:
2521 foo EQU $1234 ; This is accepted now
2524 You may use the directive to define string constants used elsewhere:
2527 ; Define the version number
2528 .define VERSION "12.3a"
2534 Macros with parameters may also be useful:
2537 .define DEBUG(message) .out message
2539 DEBUG "Assembling include file #3"
2542 Note that, while formal parameters have to be placed in braces, this is
2543 not true for the actual parameters. Beware: Since the assembler cannot
2544 detect the end of one parameter, only the first token is used. If you
2545 don't like that, use classic macros instead:
2553 (This is an example where a problem can be solved with both macro types).
2556 <sect1>Characters in macros<p>
2558 When using the <ref id="option-t" name="-t"> option, characters are translated
2559 into the target character set of the specific machine. However, this happens
2560 as late as possible. This means that strings are translated if they are part
2561 of a <tt><ref id=".BYTE" name=".BYTE"></tt> or <tt><ref id=".ASCIIZ"
2562 name=".ASCIIZ"></tt> command. Characters are translated as soon as they are
2563 used as part of an expression.
2565 This behaviour is very intuitive outside of macros but may be confusing when
2566 doing more complex macros. If you compare characters against numeric values,
2567 be sure to take the translation into account.
2572 <sect>Macro packages<label id="macropackages"><p>
2574 Using the <tt><ref id=".MACPACK" name=".MACPACK"></tt> directive, predefined
2575 macro packages may be included with just one command. Available macro packages
2579 <sect1><tt>.MACPACK generic</tt><p>
2581 This macro package defines macros that are useful in almost any program.
2582 Currently, two macros are defined:
2597 <sect1><tt>.MACPACK longbranch</tt><p>
2599 This macro package defines long conditional jumps. They are named like the
2600 short counterpart but with the 'b' replaced by a 'j'. Here is a sample
2601 definition for the "<tt/jeq/" macro, the other macros are built using the same
2606 .if .def(Target) .and ((*+2)-(Target) <= 127)
2615 All macros expand to a short branch, if the label is already defined (back
2616 jump) and is reachable with a short jump. Otherwise the macro expands to a
2617 conditional branch with the branch condition inverted, followed by an absolute
2618 jump to the actual branch target.
2620 The package defines the following macros:
2623 jeq, jne, jmi, jpl, jcs, jcc, jvs, jvc
2628 <sect>Module constructors/destructors<label id="condes"><p>
2630 <em>Note:</em> This section applies mostly to C programs, so the explanation
2631 below uses examples from the C libraries. However, the feature may also be
2632 useful for assembler programs.
2637 Using the <tt><ref id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt> and <tt><ref
2638 id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> keywords it it possible to export
2639 functions in a special way. The linker is able to generate tables with all
2640 functions of a specific type. Such a table will <em>only</em> include symbols
2641 from object files that are linked into a specific executable. This may be used
2642 to add initialization and cleanup code for library modules.
2644 The C heap functions are an example where module initialization code is used.
2645 All heap functions (<tt>malloc</tt>, <tt>free</tt>, ...) work with a few
2646 variables that contain the start and the end of the heap, pointers to the free
2647 list and so on. Since the end of the heap depends on the size and start of the
2648 stack, it must be initialized at runtime. However, initializing these
2649 variables for programs that do not use the heap are a waste of time and
2652 So the central module defines a function that contains initialization code and
2653 exports this function using the <tt/.CONSTRUCTOR/ statement. If (and only if)
2654 this module is added to an executable by the linker, the initialization
2655 function will be placed into the table of constructors by the linker. The C
2656 startup code will call all constructors before <tt/main/ and all destructors
2657 after <tt/main/, so without any further work, the heap initialization code is
2658 called once the module is linked in.
2660 While it would be possible to add explicit calls to initialization functions
2661 in the startup code, the new approach has several advantages:
2665 If a module is not included, the initialization code is not linked in and not
2666 called. So you don't pay for things you don't need.
2669 Adding another library that needs initialization does not mean that the
2670 startup code has to be changed. Before we had module constructors and
2671 destructors, the startup code for all systems had to be adjusted to call the
2672 new initialization code.
2675 The feature saves memory: Each additional initialization function needs just
2676 two bytes in the table (a pointer to the function).
2683 When creating and using module constructors and destructors, please take care
2689 The linker will only generate function tables, it will not generate code to
2690 call these functions. If you're using the feature in some other than the
2691 existing C environments, you have to write code to call all functions in a
2692 linker generated table yourself. See the <tt>condes</tt> module in the C
2693 runtime for an example on how to do this.
2696 The linker will only add addresses of functions that are in modules linked to
2697 the executable. This means that you have to be careful where to place the
2698 condes functions. If initialization is needed for a group of functions, be
2699 sure to place the initialization function into a module that is linked in
2700 regardless of which function is called by the user.
2703 The linker will generate the tables only when requested to do so by the
2704 <tt/FEATURE CONDES/ statement in the linker config file. Each table has to
2705 be requested separately.
2708 Constructors and destructors may have priorities. These priorities determine
2709 the order of the functions in the table. If your intialization or cleanup code
2710 does depend on other intiialization or cleanup code, you have to choose the
2711 priority for the functions accordingly.
2714 Besides the <tt><ref id=".CONSTRUCTOR" name=".CONSTRUCTOR"></tt> and <tt><ref
2715 id=".DESTRUCTOR" name=".DESTRUCTOR"></tt> statements, there is also a more
2716 generic command: <tt><ref id=".CONDES" name=".CONDES"></tt>. This allows to
2717 specify an additional type. Predefined types are 0 (constructor) and 1
2718 (destructor). The linker generates a separate table for each type on request.
2726 <sect>Bugs/Feedback<p>
2728 If you have problems using the assembler, if you find any bugs, or if
2729 you're doing something interesting with the assembler, I would be glad to
2730 hear from you. Feel free to contact me by email
2731 (<htmlurl url="mailto:uz@cc65.org" name="uz@cc65.org">).
2737 ca65 (and all cc65 binutils) are (C) Copyright 1998-2000 Ullrich von
2738 Bassewitz. For usage of the binaries and/or sources the following
2739 conditions do apply:
2741 This software is provided 'as-is', without any expressed or implied
2742 warranty. In no event will the authors be held liable for any damages
2743 arising from the use of this software.
2745 Permission is granted to anyone to use this software for any purpose,
2746 including commercial applications, and to alter it and redistribute it
2747 freely, subject to the following restrictions:
2750 <item> The origin of this software must not be misrepresented; you must not
2751 claim that you wrote the original software. If you use this software
2752 in a product, an acknowledgment in the product documentation would be
2753 appreciated but is not required.
2754 <item> Altered source versions must be plainly marked as such, and must not
2755 be misrepresented as being the original software.
2756 <item> This notice may not be removed or altered from any source
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