13 *NOTE: Every effort has been made to ensure the accuracy and robustness of this
14 manual and the associated software. However, because Reboot is constantly improving
15 and updating its computer software, it is unable to guarantee
16 the accuracy of printed or duplicated material after the date of publication and
17 disclaims liability for changes, errors or omissions.*
20 *Copyright © 2011-2020, Reboot*
22 *All rights reserved.*
24 *Reboot Document number F00000K-001 Rev. A.*
36 This document describes RMAC, a fast macro assembler for the 68000. RMAC currently
37 runs on the any POSIX compatible platform and the Atari ST. It was initially written
38 at Atari Corporation by programmers who needed a high performance assembler
39 for their work. Then, more than 20 years later, because there was still a need for
40 such an assembler and what was available wasn't up to expectations, Subqmod
41 and eventually Reboot continued work on the freely released source, adding Jaguar
42 extensions and fixing bugs. Over time the assembler has been extended by adding
43 support for Motorola's 68020/30/40/60, 68881/2, DSP56001 CPUs as well as Atari's
44 Object Processor (OP) found on the Atari Jaguar.
46 RMAC is intended to be used by programmers who write mostly in assembly language.
47 It was not originally a back-end to a C compiler, therefore it
48 has creature comfort that are usually neglected in such back-end assemblers. It
49 supports include files, macros, symbols with limited scope, some limited control
50 structures, and other features. RMAC is also blindingly fast, another feature
51 often sadly and obviously missing in today's assemblers.\ [1]_
53 RMAC is not entirely compatible with the AS68 assembler provided with
54 the original Atari ST Developer's Kit, but most changes are minor and a few minutes
55 with an editor should allow you to assemble your current source files. If you are an
56 AS68 user, before you leap into the unknown please read the section on Notes for
59 .. [1] It processes 30,000 lines a minute on a lightly loaded VAX 11/780; maybe 40,000 on a 520-ST with an SH-204 hard disk. Yet it could be sped up even more with some effort and without resorting to assembly language; C doesn't have to be slow!
65 * The distribution disk contains a file called README that you should read.
66 This file contains important nays about the contents of the distribution disk
67 and summarizes the most recent changes to the tools.
69 * Hard disk users can simply copy the executable files to their work or binary
70 directories. People with floppy disks can copy the executables to ramdisks,
71 install the assembler with the -q option, or even work right off of the floppies.
73 * You will need an editor that can produce "normal" format text files. Micro
74 Emacs will work well, as will most other commercial program editors, but not
75 most word processors (such as First Word or Microsoft Write).
77 * You will probably want to examine or get a listing of the file "ATARI.S". It
78 contains lots of definitions for the Atari ST, including BIOS variables, most
79 BIOS, XBIOS and GEMDOS traps, and line-A equates. We (or you) could
80 split the file up into pieces (a file for line-A equates, a file for hardware and
81 BIOS variables and so on), but RMAC is so fast that it doesn't matter
84 * Read the rest of the manual, especially the first two chapters on The Command Line and Using RMAC.
85 Also, `Notes for migrating from other 68000 assemblers`_ will save a lot of time and frustration in the long run.
86 The distribution disk contains example
87 programs that you can look at, assemble and modify.
92 The assembler is called "**rmac**" or "**rmac.prg**". The command line takes the form:
94 **rmac** [*switches*] [*files* ...]
96 A command line consists of any number of switches followed by the names of files
97 to assemble. A switch is specified with a dash (**-**) followed immediately by a key
98 character. Key characters are not case-sensitive, so "**-d**" is the same as "**-D**". Some
99 switches accept (or require) arguments to immediately follow the key character,
100 with no spaces in between.
102 Switch order is important. Command lines are processed from left to right in
103 one pass, and switches usually take effect when they are encountered. In general it
104 is best to specify all switches before the names of any input files.
106 If the command line is entirely empty then RMAC prints a copyright message
107 along with usage info and exit.
109 Input files are assumed to have the extension "**.s**"; if a filename has no extension
110 (i.e. no dot) then "**.s**" will be appended to it. More than one source filename may be
111 specified: the files are assembled into one object file, as if they were concatenated.
113 RMAC normally produces object code in "**file.o**" if "**file.s**" is the first
114 input filename. If the first input file is a special character device, the output name
115 is noname.o. The **-o** switch (see below) can be used change the output file name.
118 =================== ===========
120 =================== ===========
121 -dname\ *[=value]* Define symbol, with optional value.
122 -e\ *[file[.err]]* Direct error messages to the specified file.
123 -fa ALCYON output object file format (implied when **-ps** is enabled).
124 -fb BSD COFF output object file format.
125 -fe ELF output object file format.
126 -fr Absolute address. Source code is required to have one .org statement.
127 -fx Atari 800 com/exe/xex output object file format.
128 -i\ *path* Set include-file directory search path.
129 -l\ *[file[prn]]* Construct and direct assembly listing to the specified file.
130 -l\ *\*[filename]* Create an output listing file without pagination
131 -m\ *cpu* Switch CPU type
151 `tom - Jaguar GPU JRISC`
153 `jerry - Jaguar DSP JRISC`
155 -o\ *file[.o]* Direct object code output to the specified file.
156 +/~oall Turn all optimisations on/off
157 +o\ *0-9* Enable specific optimisation
158 ~o\ *0-9* Disable specific optimisation
160 `0: Absolute long adddresses to word (on by default)`
162 `1: move.l #x,Dn/An to moveq (on by default)`
164 `2: Word branches to short (on by default)`
166 `3: Outer displacement 0(An) to (An)`
170 `5: 68020+ Absolute long base/outer displacement to word`
172 `6: Convert null short branches to NOP`
174 `7: Convert clr.l Dn to moveq #0,Dn`
176 `8: Convert adda.w/l #x,Dy to addq.w/l #x,Dy`
178 `9: Convert adda.w/l #x,Dy to lea x(Dy),Dy`
180 'p: Enforce PC relative'
181 -p Produce an executable (**.prg**) output file.
182 -ps Produce an executable (**.prg**) output file with symbols.
183 -px Produce an executable (**.prg**) output file with extended symbols.
184 -q Make RMAC resident in memory (Atari ST only).
185 -r *size* automatically pad the size of each
186 segment in the output file until the size is an integral multiple of the
187 specified boundary. Size is a letter that specifies the desired boundary.
189 `-rw Word (2 bytes, default alignment)`
193 `-rp Phrase (8 bytes)`
195 `-rd Double Phrase (16 bytes)`
197 `-rq Quad Phrase (32 bytes)`
198 -s Warn about unoptimized long branches and applied optimisations.
199 -u Force referenced and undefined symbols global.
200 -v Verbose mode (print running dialogue).
201 -x Turn on debugging mode
202 -yn Set listing page size to n lines.
203 file\ *[s]* Assemble the specified file.
204 =================== ===========
206 The switches are described below. A summary of all the switches is given in
210 The **-d** switch permits symbols to be defined on the command line. The name
211 of the symbol to be defined immediately follows the switch (no spaces). The
212 symbol name may optionally be followed by an equals sign (=) and a decimal
213 number. If no value is specified the symbol's value is zero. The symbol at-
214 tributes are "defined, not referenced, and absolute". This switch is most useful
215 for enabling conditionally-assembled debugging code on the command line; for
220 -dDEBUG -dLoopCount=999 -dDebugLevel=55
223 The -e switch causes RMAC to send error messages to a file, instead of the
224 console. If a filename immediately follows the switch character, error messages
225 are written to the specified file. If no filename is specified, a file is created with
226 the default extension "**.err**" and with the root name taken from the first input
227 file name (e.g. error messages are written to "**file.err**" if "**file**" or "**file.s**" is
228 the first input file name). If no errors are encountered, then no error listing
229 file is created. Beware! If an assembly produces no errors, any error file from
230 a previous assembly is not removed.
233 The **-i** switch allows automatic directory searching for include files. A list of
234 semi-colon seperated directory search paths may be mentioned immediately
235 following the switch (with no spaces anywhere). For example:
239 -im:;c:include;c:include\sys
241 will cause the assembler to search the current directory of device **M**, and the
242 directories include and include\sys on drive **C**. If *-i* is not specified, and the
243 enviroment variable "**RMACPATH**" exists, its value is used in the same manner.
244 For example, users of the Mark Williams shell could put the following line in
245 their profile script to achieve the same result as the **-i** example above:
249 setenv RMACPATH="m:;c:include;c:include\sys"
251 The -l switch causes RMAC to generate an assembly listing file. If a file-
252 name immediately follows the switch character, the listing is written to the
253 specified file. If no filename is specified, then a listing file is created with the
254 default extension "**.prn**" and with the root name taken from the first input file
255 name (e.g. the listing is written to "**file.prn**" if "**file**" or "**file.s**" is the first
258 The -o switch causes RMAC to write object code on the specified file. No
259 default extension is applied to the filename. For historical reasons the filename
260 can also be seperated from the switch with a space (e.g. "**-o file**").
265 The **-p** and **-ps** switches cause RMAC to produce an Atari ST executable
266 file with the default extension of "**.prg**". If there are any external references
267 at the end of the assembly, an error message is emitted and no executable file
268 is generated. The **-p** switch does not write symbols to the executable file. The
269 **-ps** switch includes symbols (Alcyon format) in the executable file.
271 The **-q** switch is aimed primarily at users of floppy-disk-only systems. It causes
272 RMAC to install itself in memory, like a RAMdisk. Then the program
273 **m.prg** (which is very short - less than a sector) can be used instead of
274 **mac.prg**, which can take ten or twelve seconds to load. (**NOTE** not available
275 for now, might be re-implemented in the future).
277 The **-s** switch causes RMAC to generate a list of unoptimized forward
278 branches as warning messages. This is used to point out branches that could
279 have been short (e.g. "bra" could be "bra.s").
281 The **-u** switch takes effect at the end of the assembly. It forces all referenced
282 and undefined symbols to be global, exactly as if they had been made global
283 with a **.extern** or **.globl** directive. This can be used if you have a lot of
284 external symbols, and you don't feel like declaring them all external.
286 The **-v** switch turns on a "verbose" mode in which RMAC prints out (for
287 example) the names of the files it is currently processing. Verbose mode is
288 automatically entered when RMAC prompts for input with a star.
290 The **-y** switch, followed immediately by a decimal number (with no intervening
291 space), sets the number of lines in a page. RMAC will produce *N* lines
292 before emitting a form-feed. If *N* is missing or less than 10 an error message is
298 Let's assemble and link some example programs. These programs are included
299 on the distribution disk in the "**EXAMPLES**" directory - you should copy them to
300 your work area before continuing. In the following examples we adopt the conven-
301 tions that the shell prompt is a percent sign (%) and that your input (the stuff you
302 type) is presented in **bold face**.
304 If you have been reading carefully, you know that RMAC can generate
305 an executable file without linking. This is useful for making small, stand alone
306 programs that don't require externals or library routines. For example, the following
314 could be replaced by the single command:
320 since you don't need the linker for stand-alone object files.
322 Successive source files named in the command line are are concatenated, as in
323 this example, which assembles three files into a single executable, as if they were
328 % rmac -p bugs shift images
330 Of course you can get the same effect by using the **.include** directive, but sometimes
331 it is convenient to do the concatenation from the command line.
333 Here we have an unbelievably complex command line:
337 % rmac -lzorf -y95 -o tmp -ehack -Ddebug=123 -ps example
339 This produces a listing on the file called "**zorf.prn**" with 95 lines per page, writes
340 the executable code (with symbols) to a file called "**tmp.prg**", writes an error listing
341 to the file "**hack.err**", specifies an include-file path that includes the current
342 directory on the drive "**M:**," defines the symbol "**debug**" to have the value 123, and
343 assembles the file "**example.s**". (Take a deep breath - you got all that?)
345 One last thing. If there are any assembly errors, RMAC will terminate
346 with an exit code of 1. If the assembly succeeds (no errors, although there may be
347 warnings) the exit code will be 0. This is primarily for use with "make" utilities.
349 Things You Should Be Aware Of
350 '''''''''''''''''''''''''''''
351 RMAC is a one pass assembler. This means that it gets all of its work done by
352 reading each source file exactly once and then "back-patching" to fix up forward
353 references. This one-pass nature is usually transparent to the programmer, with
354 the following important exceptions:
356 * In listings, the object code for forward references is not shown. Instead, lower-
357 case "xx"s are displayed for each undefined byte, as in the following example:
361 60xx 1: bra.s.2 ;forward branch
362 xxxxxxxx dc.l .2 ;forward reference
363 60FE .2: bra.s.2 ;backward reference
365 * Forward branches (including **BSR**\s) are never optimized to their short forms.
366 To get a short forward branch it is necessary to explicitly use the ".s" suffix in
368 * Error messages may appear at the end of the assembly, referring to earlier source
369 lines that contained undefined symbols.
370 * All object code generated must fit in memory. Running out of memory is a
371 fatal error that you must deal with by splitting up your source files, re-sizing
372 or eliminating memory-using programs such as ramdisks and desk accessories,
377 RMAC does not optimize forward branches for you, but it will tell you about
378 them if you use the -s (short branch) option:
383 "example.s", line 20: warning: unoptimized short branch
385 With the -e option you can redirect the error output to a file, and determine by
386 hand (or editor macros) which forward branches are safe to explicitly declare short.
388 `Notes for migrating from other 68000 assemblers`_
389 ''''''''''''''''''''''''''''''''''''''''''''''''''
390 RMAC is not entirely compatible with the other popular assemblers
391 like Devpac or vasm. This section
392 outlines the major differences. In practice, we have found that very few changes are
393 necessary to make other assemblers' source code assemble.
395 * A semicolon (;) must be used to introduce a comment,
396 except that a star (*)
397 may be used in the first column. AS68 treated anything following the operand
398 field, preceeded by whitespace, as a comment. (RMAC treats a star that
399 is not in column 1 as a multiplication operator).
400 * Labels require colons (even labels that begin in column 1).
402 * Conditional assembly directives are called **if**, **else** and **endif**.
403 Devpac and vasm call these
404 **ifne**, **ifeq** (etc.), and **endc**.
405 * The tilde (~) character is an operator, and back-quote (`) is an illegal character.
406 AS68 permitted the tilde and back-quote characters in symbols.
407 * There are no equivalents to org or section directives.
408 The **.xdef** and **.xref** directives are not implemented,
409 but **.globl** makes these unnecessary anyway.
411 * The location counter cannot be manipulated with a statement of the form:
417 * Back-slashes in strings are "electric" characters that are used to escape C-like
418 character codes. Watch out for GEMDOS path names in ASCII constants -
419 you will have to convert them to double-backslashes.
420 * Expression evaluation is done left-to-right without operator precedence. Use parentheses to
421 force the expression evaluation as you wish.
422 * Mark your segments across files.
423 Branching to a code segment that could be identified as BSS will cause a "Error: cannot initialize non-storage (BSS) section"
424 * In 68020+ mode **Zan** and **Zri** (register suppression) is not supported.
425 * rs.b/rs.w/rs.l/rscount/rsreset can be simulated in rmac using abs.
426 For example the following source:
436 size_so_far equ rscount
448 size_so_far equ ^^abscount
449 * A rare case: if your macro contains something like:
459 then by the assembler's design this will fail as the parameters are automatically converted to hex. Changing the code like this works:
471 For those using editors other than the "Emacs" style ones (Micro-Emacs, Mince,
472 etc.) this section documents the source file format that RMAC expects.
474 * Files must contain characters with ASCII values less than 128; it is not per-
475 missable to have characters with their high bits set unless those characters are
476 contained in strings (i.e. between single or double quotes) or in comments.
478 * Lines of text are terminated with carriage-return/line-feed, linefeed alone, or
479 carriage-return alone.
481 * The file is assumed to end with the last terminated line. If there is text beyond
482 the last line terminator (e.g. control-Z) it is ignored.
489 A statement may contain up to four fields which are identified by order of ap-
490 pearance and terminating characters. The general form of an assembler statement
495 label: operator operand(s) ; comment
497 The label and comment fields are optional. An operand field may not appear
498 without an operator field. Operands are seperated with commas. Blank lines are
499 legal. If the first character on a line is an asterisk (*) or semicolon (;) then the
500 entire line is a comment. A semicolon anywhere on the line (except in a string)
501 begins a comment field which extends to the end of the line.
503 The label, if it appears, must be terminated with a single or double colon. If
504 it is terminated with a double colon it is automatically declared global. It is illegal
505 to declare a confined symbol global (see: `Symbols and Scope`_).
507 As an addition, the exclamation mark character (**!**) can be placed at the very first
508 character of a line to disbale all optimisations for that specific line, i.e.
512 !label: operator operand(s) ; comment
516 A statement may also take one of these special forms:
518 *symbol* **equ** *expression*
520 *symbol* **=** *expression*
522 *symbol* **==** *expression*
524 *symbol* **set** *expression*
526 *symbol* **reg** *register list*
528 The first two forms are identical; they equate the symbol to the value of an
529 expression, which must be defined (no forward references). The third form, double-
530 equals (==), is just like an equate except that it also makes the symbol global. (As
531 with labels, it is illegal to make a confined equate global.) The fourth form allows
532 a symbol to be set to a value any number of times, like a variable. The last form
533 equates the symbol to a 16-bit register mask specified by a register list. It is possible
534 to equate confined symbols (see: `Symbols and Scope`_). For example:
538 cr equ 13 carriage-return
540 DEBUG == 1 global debug flag
542 count set count + 1 increment variable
543 .rags reg d3-d7/a3-a6 register list
544 .cr 13 confined equate
548 Symbols may start with an uppercase or lowercase letter (A-Z a-z), an underscore
549 (**_**), a question mark (**?**) or a period (**.**). Each remaining character may be an
550 upper or lowercase letter, a digit (**0-9**), an underscore, a dollar sign (**$**), or a question
551 mark. (Periods can only begin a symbol, they cannot appear as a symbol
552 continuation character). Symbols are terminated with a character that is not a
553 symbol continuation character (e.g. a period or comma, whitespace, etc.). Case is
554 significant for user-defined symbols, but not for 68000 mnemonics, assembler direc-
555 tives and register names. Symbols are limited to 100 characters. When symbols
556 are written to the object file they are silently truncated to eight (or sixteen) char-
557 acters (depending on the object file format) with no check for (or warnings about)
560 For example, all of the following symbols are legal and unique:
564 reallyLongSymbolName .reallyLongConfinedSymbolName
565 a10 ret move dc frog aa6 a9 ????
566 .a1 .ret .move .dc .frog .a9 .9 ????
567 .0 .00 .000 .1 .11. .111 . ._
568 _frog ?zippo? sys$syetem atari Atari ATARI aTaRi
570 while all of the following symbols are illegal:
574 12days dc.10 dc.z 'quote .right.here
575 @work hi.there $money$ ~tilde
578 Symbols beginning with a period (**.**) are *confined*; their scope is between two
579 normal (unconfined) labels. Confined symbols may be labels or equates. It is illegal
580 to make a confined symbol global (with the ".globl" directive, a double colon, or a
581 double equals). Only unconfined labels delimit a confined symbol's scope; equates
582 (of any kind) do not count. For example, all symbols are unique and have unique
583 values in the following:
594 .loop: move.w -1,(a0)+
598 Confined symbols are useful since the programmer has to be much less inventive
599 about finding small, unique names that also have meaning.
601 It is legal to define symbols that have the same names as processor mnemonics
602 (such as "**move**" or "**rts**") or assembler directives (such as "**.even**"). Indeed, one
603 should be careful to avoid typographical errors, such as this classic (in 6502 mode):
611 which equates a confined symbol to a hexadecimal value, rather than setting the
612 location counter, which the .org directive does (without the equals sign).
616 The following names, in all combinations of uppercase and lowercase, are keywords
617 and may not be used as symbols (e.g. labels, equates, or the names of macros):
625 d0 d1 d2 d3 d4 d5 d6 d7
626 a0 a1 a2 a3 a4 a5 a6 a7
628 r0 r1 r2 r3 r4 r5 r6 r7
629 r8 r9 r10 r11 r12 rl3 r14 ri5
633 x x0 x1 x2 y y0 y1 y2
634 a a0 a1 a2 b b0 b1 b2 ab ba
635 mr omr la lc ssh ssl ss
636 n0 n1 n2 n3 n4 n5 n6 n7
637 m0 m1 m2 m3 m4 m5 m6 m7
638 r0 r1 r2 r3 r4 r5 r6 r7
643 Numbers may be decimal, hexadecimal, octal, binary or concatenated ASCII. The
644 default radix is decimal, and it may not be changed. Decimal numbers are specified
645 with a string of digits (**0-9**). Hexadecimal numbers are specified with a leading
646 dollar sign (**$**) followed by a string of digits and uppercase or lowercase letters (**A-F
647 a-f**). Octal numbers are specified with a leading at-sign (**@**) followed by a string
648 of octal digits (**0-7**). Binary numbers are specified with a leading percent sign
649 (**%**) followed by a string of binary digits (**0-1**). Concatenated ASCII constants are
650 specified by enclosing from one to four characters in single or double quotes. For
662 Negative numbers Are specified with a unary minus (**-**). For example:
671 Strings are contained between double (") or single ( ') quote marks. Strings may
672 contain non-printable characters by specifying "backslash" escapes, similar to the
673 ones used in the C programming language. RMAC will generate a warning if a
674 backslash is followed by a character not appearing below:
679 \n $0a line-feed (newline)
682 \r $0c1 carriage-return
688 It is possible for strings (but not symbols) to contain characters with their high
689 bits set (i.e. character codes 128...255).
691 You should be aware that backslash characters are popular in GEMDOS path
692 names, and that you may have to escape backslash characters in your existing source
693 code. For example, to get the file "'c:\\auto\\ahdi.s'" you would specify the string
694 "`c:\\\\auto\\\\ahdi.s`".
698 Register lists are special forms used with the **movem** mnemonic and the **.reg**
699 directive. They are 16-bit values, with bits 0 through 15 corresponding to registers
700 **D0** through **A7**. A register list consists of a series of register names or register
701 ranges seperated by slashes. A register range consists of two register names, Rm
702 and Rn,m<n, seperated by a dash. For example:
710 d0/d1/a0-a3/d7/a6-a7 $CF83
714 Register lists and register equates may be used in conjunction with the movem
715 mnemonic, as in this example:
719 temps reg d0-d2/a0-a2 ; temp registers
720 keeps reg d3-d7/d3-a6 ; registers to preserve
721 allregs reg d0-d7/a0-a7 ; all registers
722 movem.l #temps,-(sp) ; these two lines ...
723 movem.l d0-d2/a0-a2,-(sp) ; are identical
724 movem.l #keeps,-(sp) ; save "keep" registers
725 movem.l (sp)+,#keeps ; restore "keep" registers
730 `Order of Evaluation`_
731 ''''''''''''''''''''''
732 All values are computed with 32-bit 2's complement arithmetic. For boolean operations
733 (such as if or **assert**) zero is considered false, and non-zero is considered
736 **Expressions are evaluated strictly left-to-right, with no
737 regard for operator precedence.**
739 Thus the expression "1+2*3" evaluates to 9, not 7. However, precedence may be
740 forced with parenthesis (**()**) or square-brackets (**[]**).
744 Expressions belong to one of three classes: undefined, absolute or relocatable. An
745 expression is undefined if it involves an undefined symbol (e.g. an undeclared sym-
746 bol, or a forward reference). An expression is absolute if its value will not change
747 when the program is relocated (for instance, the number 0, all labels declared in
748 an abs section, and all Atari ST hardware register locations are absolute values).
749 An expression is relocatable if it involves exactly one symbol that is contained in a
750 text, data or BSS section.
752 Only absolute values may be used with operators other than addition (+) or
753 subtraction (-). It is illegal, for instance, to multiply or divide by a relocatable or
754 undefined value. Subtracting a relocatable value from another relocatable value in
755 the same section results in an absolute value (the distance between them, positive
756 or negative). Adding (or subtracting) an absolute value to or from a relocatable
757 value yeilds a relocatable value (an offset from the relocatable address).
759 It is important to realize that relocatable values belong to the sections they
760 are defined in (e.g. text, data or BSS), and it is not permissible to mix and match
761 sections. For example, in this code:
765 linel: dc.l line2, line1+8
766 line2: dc.l line1, line2-8
767 line3: dc.l line2-line1, 8
768 error: dc.l line1+line2, line2 >> 1, line3/4
770 Line 1 deposits two longwords that point to line 2. Line 2 deposits two longwords
771 that point to line 1. Line 3 deposits two longwords that have the absolute value
772 eight. The fourth line will result in an assembly error, since the expressions (re-
773 spectively) attempt to add two relocatable values, shift a relocatable value right by
774 one, and divide a relocatable value by four.
776 The pseudo-symbol "*****" (star) has the value that the current section's location
777 counter had at the beginning of the current source line. For example, these two
778 statements deposit three pointers to the label "**bar**":
785 Similarly, the pseudo-symbol "**$**" has the value that the current section's location
786 counter has, and it is kept up to date as the assembler deposits information
787 "across" a line of source code. For example, these two statements deposit four
788 pointers to the label "zip":
798 ================================ ==========================================
800 ================================ ==========================================
801 **-** Unary minus (2's complement).
802 **!** Logical (boolean) NOT.
803 **~** Tilde: bitwise not (l's complement).
804 **^^defined** *symbol* True if symbol has a value.
805 **^^referenced** *symbol* True if symbol has been referenced.
806 **^^streq** *stringl*,*string2* True if the strings are equal.
807 **^^macdef** *macroName* True if the macro is defined.
808 **^^abscount** Returns the size of current .abs section
809 **^^filesize** *string_filename* Returns the file size of supplied filename
810 ================================ ==========================================
812 * The boolean operators generate the value 1 if the expression is true, and 0 if it is not.
814 * A symbol is referenced if it is involved in an expression.
816 any combination of attributes: undefined and unreferenced, defined and unref-
817 erenced (i.e. declared but never used), undefined and referenced (in the case
818 of a forward or external reference), or defined and referenced.
825 =========== ==============================================
827 =========== ==============================================
828 \ + - * / The usual arithmetic operators.
829 % Modulo. Do *not* attempt to modulo by 0 or 1.
830 & | ^ Bit-wise **AND**, **OR** and **Exclusive-OR**.
831 << >> Bit-wise shift left and shift right.
832 < <= >= > Boolean magnitude comparisons.
834 <> != Boolean inequality.
835 =========== ==============================================
837 * All binary operators have the same precedence:
838 expressions are evaluated strictly left to right.
840 * Division or modulo by zero yields an assembly error.
842 * The "<>" and "!=" operators are synonyms.
844 * Note that the modulo operator (%) is also used to introduce binary constants
845 (see: `Constants`_). A percent sign should be followed by at least one space if
846 it is meant to be a modulo operator, and is followed by a '0' or '1'.
851 ============ =========================================
852 Special Form Description
853 ============ =========================================
854 **^^date** The current system date (Gemdos format).
855 **^^time** The current system time (Gemdos format).
856 ============ =========================================
858 * The "**^^date**" special form expands to the current system date, in Gemdos
859 format. The format is a 16-bit word with bits 0 ...4 indicating the day of the
860 month (1...31), bits 5...8 indicating the month (1...12), and bits 9...15
861 indicating the year since 1980, in the range 0...119.
863 * The "**^^time**" special form expands to the current system time, in Gemdos
864 format. The format is a 16-bit word with bits 0...4 indicating the current
865 second divided by 2, bits 5...10 indicating the current minute 0...59. and
866 bits 11...15 indicating the current hour 0...23.
868 `Example Expressions`_
869 ''''''''''''''''''''''
873 line address contents source code
874 ---- ------- -------- -------------------------------
875 1 00000000 4480 lab1: neg.l d0
876 2 00000002 427900000000 lab2: clr.w lab1
877 3 =00000064 equ1 = 100
878 4 =00000096 equ2 = equ1 + 50
879 5 00000008 00000064 dc.l lab1 + equ1
880 6 0000000C 7FFFFFE6 dc.l (equl + ~equ2) >> 1
881 7 00000010 0001 dc.w ^^defined equl
882 8 00000012 0000 dc.w ^^referenced lab2
883 9 00000014 00000002 dc.l lab2
884 10 00000018 0001 dc.w ^^referenced lab2
885 11 0000001A 0001 dc.w lab1 = (lab2 - 6)
887 Lines 1 through four here are used to set up the rest of the example. Line 5 deposits
888 a relocatable pointer to the location 100 bytes beyond the label "**lab1**". Line 6 is
889 a nonsensical expression that uses the and right-shift operators. Line 7 deposits
890 a word of 1 because the symbol "**equ1**" is defined (in line 3).
892 Line 8 deposits a word of 0 because the symbol "**lab2**", defined in line 2, has
893 not been referenced. But the expression in line 9 references the symbol "**lab2**", so
894 line 10 (which is a copy of line-8) deposits a word of 1. Finally, line 11 deposits a
895 word of 1 because the Boolean equality operator evaluates to true.
897 The operators "**^^defined**" and "**^^referenced**" are particularly useful in
898 conditional assembly. For instance, it is possible to automatically include debugging
899 code if the debugging code is referenced, as in:
903 lea string,a0 ; AO -> message
904 jsr debug ; print a message
906 string: dc.b "Help me, Spock!",0 ; (the message)
910 .iif ^^referenced debug, .include "debug.s"
912 The **jsr** statement references the symbol debug. Near the end of the source file, the
913 "**.iif**" statement includes the file "**debug.s**" if the symbol debug was referenced.
915 In production code, presumably all references to the debug symbol will be removed,
916 and the debug source file will not be included. (We could have as easily made the
917 symbol **debug** external, instead of including another source file).
923 Assembler directives may be any mix of upper- or lowercase. The leading periods
924 are optional, though they are shown here and their use is encouraged. Directives
925 may be preceeded by a label; the label is defined before the directive is executed.
926 Some directives accept size suffixes (**.b**, **.s**, **.w** or **.1**); the default is word (**.w**) if no
927 size is specified. The **.s** suffix is identical to **.b**. Directives relating to the 6502 are
928 described in the chapter on `6502 Support`_.
934 If the location counter for the current section is odd, make it even by adding
935 one to it. In text and data sections a zero byte is deposited if necessary.
939 Align the program counter to the next integral long boundary (4 bytes).
940 Note that GPU/DSP code sections are not contained in their own
941 segments and are actually part of the TEXT or DATA segments.
942 Therefore, to align GPU/DSP code, align the current section before and
943 after the GPU/DSP code.
947 Align the program counter to the next integral phrase boundary (8 bytes).
948 Note that GPU/DSP code sections are not contained in their own
949 segments and are actually part of the TEXT or DATA segments.
950 Therefore, to align GPU/DSP code, align the current section before and
951 after the GPU/DSP code.
955 Align the program counter to the next integral double phrase boundary (16
956 bytes). Note that GPU/DSP code sections are not contained in their own
957 segments and are actually part of the TEXT or DATA segments.
958 Therefore, to align GPU/DSP code, align the current section before and
959 after the GPU/DSP code.
963 Align the program counter to the next integral quad phrase boundary (32
964 bytes). Note that GPU/DSP code sections are not contained in their own
965 segments and are actually part of the TEXT or DATA segments.
966 Therefore, to align GPU/DSP code, align the current section before and
967 after the GPU/DSP code.
969 **.assert** *expression* [,\ *expression*...]
971 Assert that the conditions are true (non-zero). If any of the comma-seperated
972 expressions evaluates to zero an assembler warning is issued. For example:
976 .assert *-start = $76
977 .assert stacksize >= $400
985 Switch to the BSS, data or text segments. Instructions and data may not
986 be assembled into the BSS-segment, but symbols may be defined and storage
987 may be reserved with the **.ds** directive. Each assembly starts out in the text
996 Enable different flavours of the MC68000 family of CPUs. Bear in mind that not all
997 instructions and addressing modes are available in all CPUs so the correct CPU
998 should be selected at all times. Notice that it is possible to switch CPUs
1004 Enable FPU support. Note that *.68882* is on by default when selecting *.68030*.
1008 Switch to Motorola DSP56001 mode.
1010 **.org** *location* [*X:*/*Y:*/*P:*/*L:*]
1012 This directive sets the value of the location counter (or **pc**) to location, an
1013 expression that must be defined and absolute. It is legal to use the directive in
1014 the following modes: 6502, Tom, Jerry, OP, 56001 and 680x0 (only with -fr switch).
1015 Especially for the 56001 mode the *location* field **must** be prefixed with the
1016 intended section (*X:*, *Y:*, *P:* or *L:*).
1023 These directives control the optimisations that rmac applies to the source
1024 automatically. Each directive is applied immediately from the line encountered
1025 onwards. So it is possible to turn specific optimisations on and off globally
1026 (when placed at the start of the first file) or locally (by turning desired
1027 optimisations on and off at certain parts of the source). For a list of the
1028 optimisations (*n*) available please consult the table in section `The Command Line`_.
1029 **all**, as expected, turns all available optimisations on or off.
1031 Lastly, as a "creature comfort" feature, if the first column of any line is prefixed
1032 with an exclamation mark (*!*) then for that line all optimisations are turned off.
1034 **.abs** [*location*]
1036 Start an absolute section, beginning with the specified location (or zero, if
1037 no location is specified). An absolute section is much like BSS, except that
1038 locations declared with .ds are based absolute. This directive is useful for
1040 declaring structures or hardware locations.
1041 For example, the following equates:
1051 could be as easily defined as:
1062 Another interesting example worth mentioning is the emulation of "C"'s "union" keyword
1063 using *.abs*. For example, the following "C" code:
1073 union { int spf_em_colour; int spf_emx_colour; };
1074 union { int spf_em_psmask[16]; int spf_emx_colouropt; };
1077 can be expressed as:
1082 *-------------------------------------------------------*
1083 spf_w: ds.w 1 ;<- common
1088 *-------------------------------------------------------*
1090 spf_em_colour: ds.l 1 ;<- union #1
1091 spf_em_psmask: ds.l 16
1092 *-------------------------------------------------------*
1096 spf_emx_colour: ds.l 1 ;<- union #2
1097 spf_emx_colouropt: ds.l 1
1098 spf_emx_psmask: ds.l 16
1099 spf_emx_psmaskopt: ds.l 16
1102 ;*-------------------------------------------------------*
1104 move #spf_em_colour,d0
1105 move #spf_emx_colour,d0
1107 In this example, *spf_em_colour* and *spf_emx_colour* will have the same value.
1109 **.comm** *symbol*, *expression*
1111 Specifies a label and the size of a common region. The label is made global,
1112 thus confined symbols cannot be made common. The linker groups all common
1113 regions of the same name; the largest size determines the real size of the
1114 common region when the file is linked.
1116 **.ccdef** *expression*
1118 Allows you to define names for the condition codes used by the JUMP
1119 and JR instructions for GPU and DSP code. For example:
1125 jump Always,(r3) ; 'Always' is actually 0
1127 **.ccundef** *regname*
1129 Undefines a register name (regname) previously assigned using the
1130 .CCDEF directive. This is only implemented in GPU and DSP code
1133 **.dc.i** *expression*
1135 This directive generates long data values and is similar to the DC.L
1136 directive, except the high and low words are swapped. This is provided
1137 for use with the GPU/DSP MOVEI instruction.
1139 **.dc**\ [.\ *size*] *expression* [, *expression*...]
1141 Deposit initialized storage in the current section. If the specified size is word
1142 or long, the assembler will execute a .even before depositing data. If the size
1143 is .b, then strings that are not part of arithmetic expressions are deposited
1144 byte-by-byte. If no size is specified, the default is .w. This directive cannot be
1145 used in the BSS section.
1147 **.dcb**\ [.\ *size*] *expression1*, *expression2*
1149 Generate an initialized block of *expression1* bytes, words or longwords of the
1150 value *expression2*. If the specified size is word or long, the assembler will
1151 execute .even before generating data. If no size is specified, the default is **.w**.
1152 This directive cannot be used in the BSS section.
1154 **.ds**\ [.\ *size*] *expression*
1156 Reserve space in the current segment for the appropriate number of bytes,
1157 words or longwords. If no size is specified, the default size is .w. If the size
1158 is word or long, the assembler will execute .even before reserving space.
1162 Switch to Jaguar DSP assembly mode. This directive must be used
1163 within the TEXT or DATA segments.
1165 **.init**\ [.\ *size*] [#\ *expression*,]\ *expression*\ [.\ *size*] [,...]
1167 Generalized initialization directive. The size specified on the directive becomes
1168 the default size for the rest of the line. (The "default" default size is **.w**.) A
1169 comma-seperated list of expressions follows the directive; an expression may be
1170 followed by a size to override the default size. An expression may be preceeded
1171 by a sharp sign, an expression and a comma, which specifies a repeat count to
1172 be applied to the next expression. For example:
1176 .init.l -1, 0.w, #16,'z'.b, #3,0, 11.b
1178 will deposit a longword of -1, a word of zero, sixteen bytes of lower-case 'z',
1179 three longwords of zero, and a byte of 11.
1181 No auto-alignment is performed within the line, but a **.even** is done once
1182 (before the first value is deposited) if the default size is word or long.
1184 **.cargs** [#\ *expression*,] *symbol*\ [.\ *size*] [, *symbol*\ [.\ *size*].. .]
1186 Compute stack offsets to C (and other language) arguments. Each symbol is
1187 assigned an absolute value (like equ) which starts at expression and increases
1188 by the size of each symbol, for each symbol. If the expression is not supplied,
1189 the default starting value is 4. For example:
1193 .cargs #8, .fileliams.1, .openMode, .butPointer.l
1195 could be used to declare offsets from A6 to a pointer to a filename, a word
1196 containing an open mode, and a pointer to a buffer. (Note that the symbols
1197 used here are confined). Another example, a C-style "string-length" function,
1198 could be written as:
1202 _strlen:: .cargs .string ; declare arg
1203 move.l .string(sp),a0 ; a0 -> string
1204 moveq #-1,d0 ; initial size = -1
1205 .1: addq.1 #1,d0 ; bump size
1206 tst.b (a0)+ ; at end of string?
1207 bne .1 ; (no -- try again)
1208 rts ; return string length
1212 End the assembly. In an include file, end the include file and resume assembling
1213 the superior file. This statement is not required, nor are warning messages
1214 generated if it is missing at the end of a file. This directive may be used inside
1215 conditional assembly, macros or **.rept** blocks.
1217 **.equr** *expression*
1219 Allows you to name a register. This is only implemented for GPU/DSP
1220 code sections. For example:
1226 add ClipW,r0 ; ClipW actually is r19
1228 **.if** *expression*
1234 Start a block of conditional assembly. If the expression is true (non-zero) then
1235 assemble the statements between the .if and the matching **.endif** or **.else**.
1236 If the expression is false, ignore the statements unless a matching .else is
1237 encountered. Conditional assembly may be nested to any depth.
1239 It is possible to exit a conditional assembly block early from within an include
1240 file (with **end**) or a macro (with **endm**).
1242 **.iif** *expression*, *statement*
1244 Immediate version of **.if**. If the expression is true (non-zero) then the state-
1245 ment, which may be an instruction, a directive or a macro, is executed. If
1246 the expression is false, the statement is ignored. No **.endif** is required. For
1251 .iif age < 21, canDrink = 0
1252 .iif weight > 500, dangerFlag = 1
1253 .iif !(^^defined DEBUG), .include dbsrc
1255 **.macro** *name* [*formal*, *formal*,...]
1261 Define a macro called name with the specified formal arguments. The macro
1262 definition is terminated with a **.endm** statement. A macro may be exited early
1263 with the .exitm directive. See the chapter on `Macros`_ for more information.
1265 **.undefmac** *macroName* [, *macroName*...]
1267 Remove the macro-definition for the specified macro names. If reference is
1268 made to a macro that is not defined, no error message is printed and the name
1271 **.rept** *expression*
1275 The statements between the **.rept** and **.endr** directives will be repeated *expression*
1276 times. If the expression is zero or negative, no statements will be
1277 assembled. No label may appear on a line containing either of these directives.
1279 **.globl** *symbol* [, *symbol*...]
1281 **.extern** *symbol* [, *symbol*...]
1283 Each symbol is made global. None of the symbols may be confined symbols
1284 (those starting with a period). If the symbol is defined in the assembly, the
1285 symbol is exported in the object file. If the symbol is undefined at the end
1286 of the assembly, and it was referenced (i.e. used in an expression), then the
1287 symbol value is imported as an external reference that must be resolved by the
1288 linker. The **.extern** directive is merely a synonym for **.globl**.
1290 **.include** "*file*"
1292 Include a file. If the filename is not enclosed in quotes, then a default extension
1293 of "**.s**" is applied to it. If the filename is quoted, then the name is not changed
1296 Note: If the filename is not a valid symbol, then the assembler will generate an
1297 error message. You should enclose filenames such as "**atari.s**" in quotes,
1298 because such names are not symbols.
1300 If the include file cannot be found in the current directory, then the directory
1301 search path, as specified by -i on the commandline, or' by the 'RMACPATH'
1302 enviroment string, is traversed.
1304 **.incbin** "*file*" [, [*size*], [*offset*]]
1306 Include a file as a binary. This can be thought of a series of **dc.b** statements
1307 that match the binary bytes of the included file, inserted at the location of the
1308 directive. The directive is not allowed in a BSS section. Optional parameters
1309 control the amount of bytes to be included and offset from the start of the file.
1310 All the following lines are valid:
1313 .incbin "test.bin" ; Include the whole file
1314 .incbin "test.bin",,$30 ; Skip the first 48 bytes
1315 .incbin "test.bin",$70,$30 ; Include $70 bytes starting at offset $30
1316 .incbin "test.bin",$48 ; Include the file starting at offset 48 till the end
1317 .incbin "test.bin",, ; Include the whole file
1321 Issue a page eject in the listing file.
1323 **.title** "*string*"
1325 **.subttl** [-] "*string*"
1327 Set the title or subtitle on the listing page. The title should be specified on
1328 the the first line of the source program in order to take effect on the first page.
1329 The second and subsequent uses of **.title** will cause page ejects. The second
1330 and subsequent uses of .subttl will cause page ejects unless the subtitle string
1331 is preceeded by a dash (-).
1337 Enable or disable source code listing. These directives increment and decrement
1338 an internal counter, so they may be appropriately nested. They have no effect
1339 if the **-l** switch is not specified on the commandline.
1343 This directive provides unstructured flow of control within a macro definition.
1344 It will transfer control to the line of the macro containing the specified goto
1345 label. A goto label is a symbol preceeded by a colon that appears in the first
1346 column of a source line within a macro definition:
1350 where the label itself can be any valid symbol name, followed immediately by
1351 whitespace and a valid source line (or end of line). The colon **must** appear in
1354 The goto-label is removed from the source line prior to macro expansion -
1355 to all intents and purposes the label is invisible except to the .goto directive
1356 Macro expansion does not take place within the label.
1358 For example, here is a silly way to count from 1 to 10 without using **.rept**:
1366 iif count <= 10, goto loop
1371 Switch to Jaguar GPU assembly mode. This directive must be used
1372 within the TEXT or DATA segments.
1376 No. Just... no. Don't ask about it. Ever.
1378 **.prgflags** *value*
1380 Sets ST executable .PRG field *PRGFLAGS* to *value*. *PRGFLAGS* is a bit field defined as follows:
1382 ============ ====== =======
1383 Definition Bit(s) Meaning
1384 ============ ====== =======
1385 PF_FASTLOAD 0 If set, clear only the BSS area on program load, otherwise clear the entire heap.
1386 PF_TTRAMLOAD 1 If set, the program may be loaded into alternative RAM, otherwise it must be loaded into standard RAM.
1387 PF_TTRAMMEM 2 If set, the program's Malloc() requests may be satisfied from alternative RAM, otherwise they must be satisfied from standard RAM.
1388 -- 3 Currently unused.
1389 See left. 4 & 5 If these bits are set to 0 (PF_PRIVATE), the processes' entire memory space will be considered private (when memory protection is enabled).If these bits are set to 1 (PF_GLOBAL), the processes' entire memory space will be readable and writable by any process (i.e. global).If these bits are set to 2 (PF_SUPERVISOR), the processes' entire memory space will only be readable and writable by itself and any other process in supervisor mode.If these bits are set to 3 (PF_READABLE), the processes' entire memory space will be readable by any application but only writable by itself.
1390 -- 6-15 Currently unused.
1391 ============ ====== =======
1393 **.regequ** *expression*
1394 Essentially the same as **.EQUR.** Included for compatibility with the GASM
1398 Essentially the same as **.EQURUNDEF.** Included for compatibility with
1407 All of the standard Motorola 68000 mnemonics and addressing modes are supported;
1408 you should refer to **The Motorola M68000 Programmer's Reference Manual**
1409 for a description of the instruction set and the allowable addressing modes for each
1410 instruction. With one major exception (forward branches) the assembler performs
1411 all the reasonable optimizations of instructions to their short or address register
1414 Register names may be in upper or lower case. The alternate forms ``R0`` through
1415 ``R15`` may be used to specify ``D0`` through ``A7``. All register names are keywords, and
1416 may not be used as labels or symbols. None of the 68010 or 68020 register names
1417 are keywords (but they may become keywords in the future).
1422 ===================================== ===========================================
1423 Assembler Syntax Description
1424 ===================================== ===========================================
1425 *Dn* Data register direct
1426 *An* Address register direct
1427 (*An*) Address register indirect
1428 (*An*)+ Address register indirect postincrement
1429 -(*An*) Address register indirect predecrement
1430 *disp*\ (*An*) Address register indirect with displacement
1431 *bdisp*\ (*An*, *Xi*\ [.\ *size*]) Address register indirect indexed
1432 *abs*.w Absolute short
1433 *abs* Absolute (long or short)
1434 *abs*.l Forced absolute long
1435 *disp*\ (PC) Program counter with displacement
1436 *bdisp*\ (PC, *Xi*\ ) Program counter indexed
1438 ===================================== ===========================================
1440 `68020+ Addressing Modes`_
1441 ''''''''''''''''''''''''''
1443 The following addressing modes are only valid for 68020 and newer CPUs. In these
1444 modes most of the parameters like Base Displacement (**bd**), Outer Displacement
1445 (**od**), Base Register (**An**) and Index Register (**Xn**) can be omitted. RMAC
1446 will detect this and *suppress* the registers in the produced code.
1449 use a special syntax to denote register suppression like **Zan** to suppress the Base
1450 Register and **Rin** to suppress the Index Register. RMAC has no support for this
1451 behaviour nor needs it to suppress registers.
1453 In addition, other assemblers will allow reordering of the parameters (for example
1454 ([*An*,\ *bd*])). This is not allowed in RMAC.
1456 Also noteworthy is that the Index Register can be an address or data register.
1458 To avoid internal confusion the 68040/68060 registers *DC*, *IC* and *BC* are named
1459 *DC40*, *IC40* and *BC40* respectively.
1461 ====================================================== =============================================================
1462 Assembler Syntax Description
1463 ====================================================== =============================================================
1464 *bd*\ (*An*, *Xi*\ [.\ *size*][*\*scale*]) Address register indirect indexed
1465 ([*bd*,\ *An*],\ *Xn*\[.\ *siz*][*\*scale*],\ *od*) Register indirect preindexed with outer displacement
1466 ([*bd*,\ *An*,\ *Xn*\[.\ *siz*][*\*scale*],\ *od*) Register indirect postindexed with outer displacement
1467 ([*bd*,\ *PC*],\ *Xn*\[.\ *siz*][*\*scale*],\ *od*) Program counter indirect preindexed with outer displacement
1468 ([*bd*,\ *PC*,\ *Xn*\[.\ *siz*][*\*scale*],\ *od*) Program counter indirect postindexed with outer displacement
1469 ====================================================== =============================================================
1473 Since RMAC is a one pass assembler, forward branches cannot be automatically
1474 optimized to their short form. Instead, unsized forward branches are assumed to
1475 be long. Backward branches are always optimized to the short form if possible.
1477 A table that lists "extra" branch mnemonics (common synonyms for the Motorola
1478 defined mnemonics) appears below.
1480 `Linker Constraints`_
1481 '''''''''''''''''''''
1482 It is not possible to make an external reference that will fix up a byte. For example:
1487 move.l frog(pc,d0),d1
1489 is illegal (and generates an assembly error) when frog is external, because the
1490 displacement occupies a byte field in the 68000 offset word, which the object file
1495 ============== ========
1496 Alternate name Becomes:
1497 ============== ========
1507 ============== ========
1509 `Optimizations and Translations`_
1510 '''''''''''''''''''''''''''''''''
1511 The assembler provides "creature comforts" when it processes 68000 mnemonics:
1513 * **CLR.x An** will really generate **SUB.x An,An**.
1515 * **ADD**, **SUB** and **CMP** with an address register will really generate **ADDA**,
1516 **SUBA** and **CMPA**.
1518 * The **ADD**, **AND**, **CMP**, **EOR**, **OR** and **SUB** mnemonics with immediate
1519 first operands will generate the "I" forms of their instructions (**ADDI**, etc.) if
1520 the second operand is not register direct.
1522 * All shift instructions with no count value assume a count of one.
1524 * **MOVE.L** is optimized to **MOVEQ** if the immediate operand is defined and
1525 in the range -128...127. However, **ADD** and **SUB** are never translated to
1526 their quick forms; **ADDQ** and **SUBQ** must be explicit.
1528 * All optimisations are controllable using the **.opt** directive. Refer to its
1529 description in section `Directives`_.
1531 * All optimisations are turned off for any source line that has an exclamation mark
1532 (*!*) on their first column.
1534 * Optimisation switches 0, 1 and 2 are turned on by default for legacy reasons.
1535 All other levels are off by default. (refer to section `The Command Line`_
1536 for a description of all the switches).
1538 * Optimisation warnings are off by default. Invoke RMAC with the *-s* switch to
1539 turn on warnings in console and listing output.
1541 * In DSP56001 mode size optimisations are on by default. Currently there is no
1542 way to disable this behaviour.
1544 * In GPU/DSP code sections, you can use JUMP (Rx) in place of JUMP T, (Rx) and JR
1545 (Rx) in place of JR T,(Rx).
1547 * RMAC tests all GPU/DSP restrictions and corrects them wherever possible (such as
1548 inserting a NOP instruction when needed).
1550 * The *(Rx+N)* addressing mode for GPU/DSP instructions is optimized to *(Rx)*
1555 `Macro declaration`_
1556 ''''''''''''''''''''
1557 A macro definition is a series of statements of the form:
1560 .macro name [ formal-arg, ...]
1564 statements making up the macro body
1570 The name of the macro may be any valid symbol that is not also a 68000 instruction
1571 or an assembler directive. (The name may begin with a period - macros cannot
1572 be made confined the way labels or equated symbols can be). The formal argument
1573 list is optional; it is specified with a comma-seperated list of valid symbol names.
1574 Note that there is no comma between the name of the macro and the name of the
1575 first formal argument. It is not advised to begin an argument name with a numeric
1578 A macro body begins on the line after the **.macro** directive. All instructions
1579 and directives, except other macro definitions, are legal inside the body.
1581 The macro ends with the **.endm** statement. If a label appears on the line with
1582 this directive, the label is ignored and a warning is generated.
1584 `Parameter Substitution`_
1585 '''''''''''''''''''''''''
1586 Within the body, formal parameters may be expanded with the special forms:
1592 The second form (enclosed in braces) can be used in situations where the characters
1593 following the formal parameter name are valid symbol continuation characters. This
1594 is usually used to force concatentation, as in:
1599 \(godzilla}vs\{reagan}
1601 The formal parameter name is terminated with a character that is not valid in
1602 a symbol (e.g. whitespace or puncuation); optionally, the name may be enclosed in
1603 curly-braces. The names must be symbols appearing on the formal argument list,
1604 or a single decimal digit (``\1`` corresponds to the first argument, ``\2`` to the second,
1605 ``\9`` to the ninth, and ``\0`` to the tenth). It is possible for a macro to have more than
1606 ten formal arguments, but arguments 11 and on must be referenced by name, not
1609 Other special forms are:
1611 ============ ================================================
1612 Special Form Description
1613 ============ ================================================
1614 ``\\`` a single "\",
1615 ``\~`` a unique label of the form "Mn"
1616 ``\#`` the number of arguments actually specified
1617 ``\!`` the "dot-size" specified on the macro invocation
1618 ``\?name`` conditional expansion
1619 ``\?{name}`` conditional expansion
1620 ============ ================================================
1622 The last two forms are identical: if the argument is specified and is non-empty, the
1623 form expands to a "1", otherwise (if the argument is missing or empty) the form
1626 The form "``\!``" expands to the "dot-size" that was specified when the macro
1627 was invoked. This can be used to write macros that behave differently depending
1628 on the size suffix they are given, as in this macro which provides a synonym for the
1633 .macro deposit value
1636 deposit.b 1 ; byte of 1
1637 deposit.w 2 ; word of 2
1638 deposit.l 3 ; longvord of 3
1639 deposit 4 ; word of 4 (no explicit size)
1643 A previously-defined macro is called when its name appears in the operation field of
1644 a statement. Arguments may be specified following the macro name; each argument
1645 is seperated by a comma. Arguments may be empty. Arguments are stored for
1646 substitution in the macro body in the following manner:
1648 * Numbers are converted to hexadecimal.
1650 * All spaces outside strings are removed.
1652 * Keywords (such as register names, dot sizes and "^^" operators) are converted
1655 * Strings are enclosed in double-quote marks (").
1657 For example, a hypothetical call to the macro "``mymacro``", of the form:
1658 ``mymacro A0, , 'Zorch' / 32, "^^DEFINED foo, , , tick tock``
1660 will result in the translations:
1662 ======== ================= =================================================
1663 Argument Expansion Comment
1664 ======== ================= =================================================
1665 ``\1`` ``a0`` "``A0``" converted to lower-case
1667 ``\3`` ``"Zorch"/$20`` "``Zorch``" in double-quotes, 32 in hexadecimal
1668 ``\4`` ``^^defined foo`` "``^^DEFINED``" converted to lower-case
1671 ``\7`` ``ticktock`` spaces removed (note concatenation)
1672 ======== ================= =================================================
1674 The **.exitm** directive will cause an immediate exit from a macro body. Thus
1675 the macro definition:
1680 .iif !\?source, .exitm ; exit if source is empty
1681 move \source,d0 ; otherwise, deposit source
1684 will not generate the move instruction if the argument **"source"** is missing from
1685 the macro invocation.
1687 The **.end**, **.endif** and **.exitm** directives all pop-out of their include levels
1688 appropriately. That is, if a macro performs a **.include** to include a source file, an
1689 executed **.exitm** directive within the include-file will pop out of both the include-file
1692 Macros may be recursive or mutually recursive to any level, subject only to
1693 the availability of memory. When writing recursive macros, take care in the coding
1694 of the termination condition(s). A macro that repeatedly calls itself will cause the
1695 assembler to exhaust its memory and abort the assembly.
1700 The Gemdos macro is used to make file system calls. It has two parameters, a
1701 function number and the number of bytes to clean off the stack after the call. The
1702 macro pushes the function number onto the stack and does the trap to the file
1703 system. After the trap returns, conditional assembly is used to choose an addq or
1704 an **add.w** to remove the arguments that were pushed.
1708 .macro Gemdos trpno, clean
1709 move.w #\trpno,-(sp) ; push trap number
1710 trap #1 ; do GEMDOS trap
1712 addq #\clean,sp ; clean-up up to 8 bytes
1714 add.w #\clean,sp ; clean-up more than 8 bytes
1718 The Fopen macro is supplied two arguments; the address of a filename, and
1719 the open mode. Note that plain move instructions are used, and that the caller of
1720 the macro must supply an appropriate addressing mode (e.g. immediate) for each
1725 .macro Fopen file, mode
1726 movs.w \mode,-(sp) ;push open mode
1727 move.1 \file,-(sp) ;push address of tile name
1728 Gemdos $3d,8 ;do the GEMDOS call
1731 The **String** macro is used to allocate storage for a string, and to place the
1732 string's address somewhere. The first argument should be a string or other expres-
1733 sion acceptable in a dc.b directive. The second argument is optional; it specifies
1734 where the address of the string should be placed. If the second argument is omitted,
1735 the string's address is pushed onto the stack. The string data itself is kept in the
1740 .macro String str,loc
1741 .if \?loc ; if loc is defined
1742 move.l #.\~,\loc ; put the string's address there
1744 pea .\~ ; push the string's address
1746 .data ; put the string data
1747 .\~: dc.b \str,0 ; in the data segment
1748 .text ; and switch back to the text segment
1751 The construction "``.\~``" will expand to a label of the form "``.M``\ *n*" (where *n* is
1752 a unique number for every macro invocation), which is used to tag the location of
1753 the string. The label should be confined because the macro may be used along with
1754 other confined symbols.
1756 Unique symbol generation plays an important part in the art of writing fine
1757 macros. For instance, if we needed three unique symbols, we might write "``.a\~``",
1758 "``.b\~``" and "``.c\~``".
1762 Repeat-blocks provide a simple iteration capability. A repeat block allows a range
1763 of statements to be repeated a specified number of times. For instance, to generate
1764 a table consisting of the numbers 255 through 0 (counting backwards) you could
1769 .count set 255 ; initialize counter
1770 .rept 256 ; repeat 256 times:
1771 dc.b .count ; deposit counter
1772 .count set .count - 1 ; and decrement it
1773 .endr ; (end of repeat block)
1775 Repeat blocks can also be used to duplicate identical pieces of code (which are
1776 common in bitmap-graphics routines). For example:
1780 .rept 16 ; clear 16 words
1781 clr.w (a0)+ ; starting at AO
1784 `Jaguar GPU/DSP Mode`_
1785 ======================
1787 RMAC will generate code for the Atari Jaguar GPU and DSP custom RISC (Reduced
1788 Instruction Set Computer) processors. See the Atari Jaguar Software reference Manual - Tom
1789 & Jerry for a complete listing of Jaguar GPU and DSP assembler mnemonics and addressing
1794 The following condition codes for the GPU/DSP JUMP and JR instructions are built-in:
1798 CC (Carry Clear) = %00100
1799 CS (Carry Set) = %01000
1802 NE (Not Equal) = %00001
1804 HI (Higher) = %00101
1807 `Jaguar Object Processor Mode`_
1808 ===============================
1813 An assembler to generate object lists for the Atari Jaguar's Object processor.
1819 To really utilize the OP properly, it needs an assembler. Otherwise, what
1820 happens is you end up writing an assembler in your code to assemble the OP
1821 list, and that's a real drag--something that *should* be handled by a proper
1826 ''''''''''''''''''''
1828 The OP assembler works similarly to the RISC assembler; to enter the OP
1829 assembler, you put the .objproc directive in your code (N.B.: like the RISC
1830 assembler, it only works in a TEXT or DATA section). From there, you build
1831 the OP list how you want it and go from there. A few caveats: you will want
1832 to put a .org directive at the top of your list, and labels that you want to
1833 be able to address in 68xxx code (for moving from a data section to an
1834 address where it will be executed by the OP, for example) should be created
1838 `What are the opcodes?`_
1839 ''''''''''''''''''''''''
1841 They are **bitmap**, **scbitmap**, **gpuobj**, **branch**, **stop**, **nop**, and **jump**. **nop** and **jump**
1842 are psuedo-ops, they are there as a convenience to the coder.
1845 `What are the proper forms for these opcodes?`_
1846 '''''''''''''''''''''''''''''''''''''''''''''''
1848 They are as follows:
1850 **bitmap** *data addr*, *xloc*, *yloc*, *dwidth*, *iwidth*, *iheight*, *bpp*,
1851 *pallete idx*, *flags*, *firstpix*, *pitch*
1853 **scbitmap** *data addr*, *xloc*, *yloc*, *dwidth*, *iwidth*, *iheight*,
1854 *xscale*, *yscale*, *remainder*, *bpp*, *pallete idx*,
1855 *flags*, *firstpix*, *pitch*
1857 **gpuobj** *line #*, *userdata* (bits 14-63 of this object)
1859 **branch** VC *condition (<, =, >)* *line #*, *link addr*
1861 **branch** OPFLAG, *link addr*
1863 **branch** SECHALF, *link addr*
1869 **jump** *link addr*
1871 Note that the *flags* field in bitmap and scbitmap objects consist of the
1872 following: **REFLECT**, **RMW**, **TRANS**, **RELEASE**. They can be in any order (and
1873 should be separated by whitespace **only**), and you can only put a maximum of
1874 four of them in. Further note that with bitmap and scbitmap objects, all the
1875 parameters after *data addr* are optional--if they are omitted, they will
1876 use defaults (mostly 0, but 1 is the default for pitch). Also, in the
1877 scbitmap object, the *xscale*, *yscale*, and *remainder* fields can be
1878 floating point constants/expressions. *data addr* can refer to any address
1879 defined (even external!) and the linker (rln v1.6.0 or greater) will
1880 properly fix up the address.
1886 Pretty much what you expect. It's beyond the scope of this little note to
1887 explain the Jaguar's Object Processor and how it operates, so you'll have to
1888 seek explanations for how they work elsewhere.
1891 `Why do I want to put a *.org* directive at the top of my list?`_
1892 '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1894 You want to put a *.org* directive at the top of your list because otherwise
1895 the assembler will not know where in memory the object list is supposed
1896 go--then when you move it to its destination, the object link addresses will
1897 all be wrong and it won't work.
1900 `Why would I copy my object list to another memory location?`_
1901 ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1903 Simple: because the OP destroys the list as it uses it to render the screen.
1904 If you don't keep a fresh copy stashed away somewhere to refresh it before
1905 the next frame is rendered, what you see on the screen will not be what you
1906 expect, as the OP has scribbled all over it!
1909 `Does the assembler do anything behind my back?`_
1910 '''''''''''''''''''''''''''''''''''''''''''''''''
1912 Yes, it will emit **NOP** s to ensure that bitmaps and scbitmaps are on proper
1913 memory boundaries, and fixup link addresses as necessary. This is needed
1914 because of a quirk in how the OP works (it ORs constants on the address
1915 lines to get the phrases it needs and if they are not zeroes, it will fail
1916 in bizarre ways). It will also set all *ypos* constants on the correct
1917 half-line (as that's how the OP views them).
1920 `Why can't I define the link addresses for all the objects?`_
1921 '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1923 You really, *really* don't want to do this. Trust me on this one.
1925 `How about an example of an object list?`_
1926 ''''''''''''''''''''''''''''''''''''''''''
1934 objects: ; This is the label you will use to address this in 68K code
1935 .objproc ; Engage the OP assembler
1936 .org objList ; Tell the OP assembler where the list will execute
1938 branch VC < 69, .stahp ; Branch to the STOP object if VC < 69
1939 branch VC > 241, .stahp ; Branch to the STOP object if VC > 241
1940 bitmap bRAM, 22, 70, 24, 24, 22, 4
1941 bitmap bRAM, 20+96+96, 70, 24, 24, 22, 4, 0, REFLECT
1942 scbitmap tms, 20, 70, 1, 1, 8, 3.0, 3.0, 2.9999, 0, 0, TRANS
1943 scbitmap tmsShadow, 23, 73, 1, 1, 8, 3.0, 3.0, 2.9999, 0, 3, TRANS
1944 bitmap sbRelBM, 30, 108, 3, 3, 8, 0, 1, TRANS
1945 bitmap txt1BM, 46, 132, 3, 3, 8, 0, 2, TRANS
1946 bitmap txt2BM, 46, 148, 3, 3, 8, 0, 2, TRANS
1947 bitmap txt3BM, 22, 164, 3, 3, 8, 0, 2, TRANS
1958 RMAC fully supports Motorola's DSP56001 as used on the Atari Falcon and can output
1959 binary code in the two most popular formats: *.lod* (ASCII dump, supported by the
1960 Atari Falcon XBIOS) and *.p56* (binary equivalent of *.lod*)
1962 `Differences from Motorola's assembler`_
1963 ''''''''''''''''''''''''''''''''''''''''
1965 - Motorola's assembler aliases **and #xxx,reg** with **andi #xxx,reg** and can
1966 distinguish between the two. rmac needs the user to be explicit and will
1967 generate an error if the programmer tries to use syntax from one instruction
1969 - Similarly Motorola's assembler can alias **move** with **movec**, **movep**
1970 and **movem**. rmac also not accept such aliasing and generate an error.
1971 - Motorola's assembler uses the underscore character (*_*) to define local
1972 labels. In order for rmac to maintain a uniform syntax across all platforms,
1973 such labels will not be treated as local.
1974 - Macros syntax is different from Motorola's assembler. This includes local
1975 labels inside macros. The user is encouraged to study the `Macros`_ section
1976 and compare syntactical differences.
1977 - Motorola's assembler allows reordering of addressing modes **x:**, **x:r**,
1978 **r:y**, **x:y**. rmac will only accept syntax as is defined on the reference
1980 - In **L:** section a dc value cannot be 12 hex digits like Motorola's assmebler.
1981 Instead, the value needs to be split into two parts separated by **:**.
1985 RMAC will generate code for the Motorola 6502 microprocessor. This chapter
1986 describes extra addressing modes and directives used to support the 6502.
1988 As the 6502 object code is not linkable (currently there is no linker) external
1989 references may not be made. (Nevertheless, RMAC may reasonably be used for
1990 large assemblies because of its blinding speed.)
1992 `6502 Addressing Modes`_
1993 ''''''''''''''''''''''''
1994 All standard 6502 addressing modes are supported, with the exception of the
1995 accumulator addressing form, which must be omitted (e.g. "ror a" becomes "ror").
1996 Five extra modes, synonyms for existing ones, are included for compatibility with
1997 the Atari Coinop assembler.
1999 ============== ========================================
2000 *empty* implied or accumulator (e.g. tsx or ror)
2001 *expr* absolute or zeropage
2003 #<\ *expr* immediate low byte of a word
2004 #>\ *expr* immediate high byte of a word
2005 (*expr*,x) indirect X
2006 (*expr*),y indirect Y
2010 @\ *expr*\ (x) indirect X
2011 @\ *expr*\ (y) indirect Y
2013 x,\ *expr* indexed X
2014 y,\ *expr* indexed Y
2015 ============== ========================================
2020 This directive enters the 6502 section. The location counter is undefined, and
2021 must be set with ".org" before any code can be generated.
2023 The "``dc.w``" directive will produce 6502-format words (low byte first). The
2024 68000's reserved keywords (``d0-d7/a0-a7/ssp/usp`` and so on) remain reserved
2025 (and thus unusable) while in the 6502 section. The directives **globl**, **dc.l**,
2026 **dcb.l**, **text**, **data**, **bss**, **abs**, **even** and **comm** are illegal in the 6502 section.
2027 It is permitted, though probably not useful, to generate both 6502 and 68000
2028 code in the same object file.
2030 This directive leaves the 6502 segment and returns to the 68000's text segment.
2031 68000 instructions may be assembled as normal.
2033 This directive sets the value of the location
2034 counter (or **pc**) to location, an expression that must be defined, absolute, and
2039 It is possible to assemble "beyond" the microprocessor's 64K address space, but
2040 attempting to do so will probably screw up the assembler. DO NOT attempt
2041 to generate code like this:
2050 the third NOP in this example, at location $10000, may cause the assembler
2051 to crash or exhibit spectacular schizophrenia. In any case, RMAC will give
2052 no warning before flaking out.
2054 `6502 Object Code Format`_
2055 ''''''''''''''''''''''''''
2056 Traditionally Madmac had a very kludgy way of storing object files. This has been
2057 replaced with a more standard *.exe* (or *.com* or *.xex* if you prefer). Briefly,
2058 the *.exe* format consists of chunks of this format (one after the other):
2063 00-01 $FFFF - Indicates a binary load file. Mandatory for first segment, optional for any other segment
2064 02-03 Start Address. The segment will load at this address
2065 04-05 End Address. The last byte to load for this segment
2066 06-.. The actual segment data to load (End Address-Start Address + 1 bytes)
2071 `When Things Go Wrong`_
2072 '''''''''''''''''''''''
2073 Most of RMAC's error messages are self-explanatory. They fall into four classes:
2074 warnings about situations that you (or the assembler) may not be happy about,
2075 errors that cause the assembler to not generate object files, fatal errors that cause
2076 the assembler to abort immediately, and internal errors that should never happen.\ [3]_
2078 You can write editor macros (or sed or awk scripts) to parse the error messages
2079 RMAC generates. When a message is printed, it is of the form:
2081 "*filename*" , ``line`` *line-number*: *message*
2083 The first element, a filename enclosed in double quotes, indicates the file that generated
2084 the error. The filename is followed by a comma, the word "``line``", and a line
2085 number, and finally a colon and the text of the message. The filename "**(\*top\*)**"
2086 indicates that the assembler could not determine which file had the problem.
2088 The following sections list warnings, errors and fatal errors in alphabetical
2089 order, along with a short description of what may have caused the problem.
2091 .. [3] If you come across an internal error, we would appreciate it if you would contact Atari Technical Support and let us know about the problem.
2095 **bad backslash code in string**
2096 You tried to follow a backslash in a string with a character that the assembler
2097 didn't recognize. Remember that RMAC uses a C-style escape system in
2100 You specified a label before a macro, **rept** or **endm** directive. The assembler
2101 is warning you that the label will not be defined in the assembly.
2102 **unoptimized short branch**
2103 This warning is only generated if the -s switch is specified on the command
2104 line. The message refers to a forward, unsized long branch that you could have
2111 As a result of previous errors, the assembler cannot continue processing. The
2112 assembly is aborted.
2113 **line too long as a result of macro expansion**
2114 When a source line within a macro was expanded, the resultant line was too
2115 long for RMAC (longer than 200 characters or so).
2118 **memory exhausted**
2119 The assembler ran out of memory. You should (1) split up your source files
2120 and assemble them seperately, or (2) if you have any ramdisks or RAM-resident
2121 programs (like desk accessories) decrease their size so that the assembler has
2122 more RAM to work with. As a rule of thumb, pure 68000 code will use up to
2123 twice the number of bytes contained in the source files, whereas 6502 code will
2124 use 64K of ram right away, plus the size of the source files. The assembler itself
2125 uses about 80K bytes. Get out your calculator...
2127 The assembler ran across an **endm** directive when it wasn't expecting to see
2128 one. The assembly is aborted. Check the nesting of your macro definitions -
2129 you probably have an extra **endm**.
2137 Syntax error in **.cargs** directive.
2139 **.comm symbol already defined**
2141 You tried to ``.comm`` a symbol that was already defined.
2143 **.ds permitted only in BSS**
2145 You tried to use ``.ds`` in the text or data section.
2147 **.init not permitted in BSS or ABS**
2149 You tried to use ``.init`` in the BSS or ABS section.
2151 **Cannot create:** *filename*
2153 The assembler could not create the indicated filename.
2155 **External quick reference**
2157 You tried to make the immediate operand of a **moveq**, **subq** or **addq** instruction external.
2159 **PC-relative expr across sections**
2161 You tried to make a PC-relative reference to a location contained in another
2164 **[bwsl] must follow '.' in symbol**
2166 You tried to follow a dot in a symbol name with something other than one of
2167 the four characters 'B', 'W', 'S' or 'L'.
2169 **addressing mode syntax**
2171 You made a syntax error in an addressing mode.
2175 One of your **.assert** directives failed!
2177 **bad (section) expression**
2179 You tried to mix and match sections in an expression.
2181 **bad 6502 addressing mode**
2183 The 6502 mnemonic will not work with the addressing mode you specified.
2187 There's a syntax error in the expression you typed.
2189 **bad size specified**
2191 You tried to use an inappropriate size suffix for the instruction. Check your
2192 68000 manual for allowable sizes.
2196 You can't use .b (byte) mode with the **movem** instruction.
2198 **cannot .globl local symbol**
2200 You tried to make a confined symbol global or common.
2202 **cannot initialize non-storage (BSS) section**
2204 You tried to generate instructions (or data, with dc) in the BSS or ABS section.
2206 **cannot use '.b' with an address register**
2208 You tried to use a byte-size suffix with an address register. The 68000 does not
2209 perform byte-sized address register operations.
2211 **directive illegal in .6502 section**
2213 You tried to use a 68000-oriented directive in the 6502 section.
2217 The expression you typed involves a division by zero.
2219 **expression out of range**
2221 The expression you typed is out of range for its application.
2223 **external byte reference**
2225 You tried to make a byte-sized reference to an external symbol, which the
2226 object file format will not allow.
2228 **external short branch**
2230 You tried to make a short branch to an external symbol, which the linker cannot
2233 **extra (unexpected) text found after addressing mode**
2235 RMAC thought it was done processing a line, but it ran up against "extra"
2236 stuff. Be sure that any comment on the line begins with a semicolon, and check
2237 for dangling commas, etc.
2239 **forward or undefined .assert**
2241 The expression you typed after a **.assert** directive had an undefined value.
2242 Remember that RMAC is one-pass.
2244 **hit EOF without finding matching .endif**
2246 The assembler fell off the end of last input file without finding a **.endif** to
2247 match an . it. You probably forgot a **.endif** somewhere.
2249 **illegal 6502 addressing mode**
2251 The 6502 instruction you typed doesn't work with the addressing mode you
2254 **illegal absolute expression**
2256 You can't use an absolute-valued expression here.
2258 **illegal bra.s with zero offset**
2260 You can't do a short branch to the very next instruction (read your 68000
2263 **illegal byte-sized relative reference**
2265 The object file format does not permit bytes contain relocatable values; you
2266 tried to use a byte-sized relocatable expression in an immediate addressing
2269 **illegal character**
2271 Your source file contains a character that RMAC doesn't allow. (most
2272 control characters fall into this category).
2274 **illegal initialization of section**
2276 You tried to use .dc or .dcb in the BSS or ABS sections.
2278 **illegal relative address**
2280 The relative address you specified is illegal because it belongs to a different
2283 **illegal word relocatable (in .PRG mode)**
2285 You can't have anything other than long relocatable values when you're gener-
2286 ating a **.PRG** file.
2288 **inappropriate addressing mode**
2290 The mnemonic you typed doesn't work with the addressing modes you specified.
2291 Check your 68000 manual for allowable combinations.
2293 **invalid addressing mode**
2295 The combination of addressing modes you picked for the **movem** instruction
2296 are not implemented by the 68000. Check your 68000 reference manual for
2299 **invalid symbol following ^^**
2301 What followed the ^^ wasn't a valid symbol at all.
2303 **mis-nested .endr**
2305 The assembler found a **.endr** directive when it wasn't prepared to find one.
2306 Check your repeat-block nesting.
2308 **mismatched .else**
2310 The assembler found a **.else** directive when it wasn't prepared to find one.
2311 Check your conditional assembly nesting.
2313 **mismatched .endif**
2315 The assembler found a **.endif** directive when it wasn't prepared to find one.
2316 Check your conditional assembly nesting.
2322 **missing argument name**
2324 **missing close parenthesis ')'**
2326 **missing close parenthesis ']'**
2330 **missing filename**
2336 **missing symbol or string**
2338 The assembler expected to see a symbol/filename/string (etc...), but found
2339 something else instead. In most cases the problem should be obvious.
2341 **misuse of '.', not allowed in symbols**
2343 You tried to use a dot (.) in the middle of a symbol name.
2347 The expression you typed involves a modulo by zero.
2349 **multiple formal argument definition**
2351 The list of formal parameter names you supplied for a macro definition includes
2352 two identical names.
2354 **multiple macro definition**
2356 You tried to define a macro which already had a definition.
2358 **non-absolute byte reference**
2360 You tried to make a byte reference to a relocatable value, which the object file
2361 format does not allow.
2363 **non-absolute byte value**
2365 You tried to dc.b or dcb.b a relocatable value. Byte relocatable values are
2366 not permitted by the object file format.
2368 **register list order**
2370 You tried to specify a register list like **D7-D0**, which is illegal. Remember
2371 that the first register number must be less than or equal to the second register
2374 **register list syntax**
2376 You made an error in specifying a register list for a **.reg** directive or a **.movem**
2379 **symbol list syntax**
2381 You probably forgot a comma between the names of two symbols in a symbol
2382 list, or you left a comma dangling on the end of the line.
2386 This is a "catch-all" error.
2388 **undefined expression**
2390 The expression has an undefined value because of a forward reference, or an
2391 undefined or external symbol.
2393 **unimplemented addressing mode**
2395 You tried to use 68020 "square-bracket" notation for a 68020 addressing mode.
2396 RMAC does not support 68020 addressing modes.
2398 **unimplemented directive**
2400 You have found a directive that didn't appear in the documentation. It doesn't
2403 **unimplemented mnemonic**
2407 **unknown symbol following ^^**
2409 You followed a ^^ with something other than one of the names defined, ref-
2412 **unsupported 68020 addressing mode**
2414 The assembler saw a 68020-type addressing mode. RMAC does not assem-
2415 ble code for the 68020 or 68010.
2417 **unterminated string**
2419 You specified a string starting with a single or double quote, but forgot to type
2424 The assembler had a problem writing an object file. This is usually caused by
2425 a full disk, or a bad sector on the media.