rgbasm(1) — Game Boy assembler
SYNOPSIS
rgbasm |
[-EHhLlVvw ] [-b
chars] [-D
name[=value]]
[-g chars]
[-I path]
[-M depend_file]
[-MG ] [-MP ]
[-MT target_file]
[-MQ target_file]
[-o out_file]
[-P include_file]
[-p pad_value]
[-Q fix_precision]
[-r recursion_depth]
[-W warning]
asmfile |
DESCRIPTION
The rgbasm
program creates an RGB object
file from an assembly source file. The input asmfile
can be a path to a file, or -
to read from standard
input.
Note that options can be abbreviated as long as the abbreviation
is unambiguous: --verb
is
--verbose
, but --ver
is
invalid because it could also be --version
. The
arguments are as follows:
-b
chars,--binary-digits
chars- Change the two characters used for binary constants. The defaults are 01.
-D
name[=value],--define
name[=value]- Add a string symbol to the compiled source code. This is equivalent to
‘
name
’ in code, or ‘EQUS
"value"name
’ if value is not specified.EQUS
"1" -E
,--export-all
- Export all labels, including unreferenced and local labels.
-g
chars,--gfx-chars
chars- Change the four characters used for gfx constants. The defaults are 0123.
-H
,--nop-after-halt
- By default,
rgbasm
inserts anop
instruction immediately after anyhalt
instruction, but this has been deprecated and prints a warning message the first time it occurs. The-H
option opts into this insertion, so no warning will be printed. -h
,--halt-without-nop
- Disables inserting a
nop
instruction immediately after anyhalt
instruction. -I
path,--include
path- Add a new “include path; path” must
point to a directory. When a
INCLUDE
(including the implicit one from-P
) orINCBIN
is attempted,rgbasm
first looks up the provided path from its working directory; if this fails, it tries again from each of the “include path” directories, in the order they were provided. -L
,--preserve-ld
- By default,
rgbasm
optimizes loads of the formLD [$FF00+n8],A
into the opcodeLDH [$FF00+n8],A
, but this has been deprecated and prints a warning message the first time it occurs. The-L
option disables this optimization. -l
,--auto-ldh
- Optimize loads of the form
LD [$FF00+n8],A
into the opcodeLDH [$FF00+n8],A
. -M
depend_file,--dependfile
depend_file- Print make(1) dependencies to depend_file.
-MG
- To be used in conjunction with
-M
. This makesrgbasm
assume that missing files are auto-generated: whenINCLUDE
(including the implicit one from-P
) orINCBIN
is attempted on a non-existent file, it is added as a dependency, thenrgbasm
exits normally instead of erroring out. This feature is used in automatic updating of makefiles. -MP
- When enabled, this causes a phony target to be added for each dependency other than the main file. This prevents make(1) from erroring out when dependency files are deleted.
-MT
target_file- Add a target to the rules emitted by
-M
. The exact string provided will be written, including spaces and special characters.is equivalent to-MT
fileA-MT
fileB. If neither this nor-MT
'fileA fileB'-MQ
is specified, the output file name is used. -MQ
target_file- Same as
-MT
, but additionally escapes any special make(1) characters, essentially ‘$’. -o
out_file,--output
out_file- Write an object file to the given filename.
-P
include_file,--preinclude
include_file- Pre-include a file. This acts as if a
‘
’ was read before the input asmfile.INCLUDE
"include_file" -p
pad_value,--pad-value
pad_value- When padding an image, pad with this value. The default is 0x00.
-Q
fix_precision,--q-precision
fix_precision- Use this as the precision of fixed-point numbers after the decimal point,
unless they specify their own precision. The default is 16, so fixed-point
numbers are Q16.16 (since they are 32-bit integers). The argument may
start with a ‘
.
’ to match the Q notation, for example, ‘
’.-Q
.16 -r
recursion_depth,--recursion-depth
recursion_depth- Specifies the recursion depth past which RGBASM will assume being in an infinite loop. The default is 64.
-V
,--version
- Print the version of the program and exit.
-v
,--verbose
- Be verbose.
-W
warning,--warning
warning- Set warning flag warning. A warning message will be printed if warning is an unknown warning flag. See the DIAGNOSTICS section for a list of warnings.
-w
- Disable all warning output, even when turned into errors.
DIAGNOSTICS
Warnings are diagnostic messages that indicate possibly erroneous behavior that does not necessarily compromise the assembling process. The following options alter the way warnings are processed.
-Werror
- Make all warnings into errors.
-Werror=
- Make the specified warning into an error. A warning's name is appended
(example:
-Werror=obsolete
), and this warning is implicitly enabled and turned into an error. This is an error if used with a meta warning, such as-Werror=all
.
The following warnings are “meta” warnings, that enable a collection of other warnings. If a specific warning is toggled via a meta flag and a specific one, the more specific one takes priority. The position on the command-line acts as a tie breaker, the last one taking effect.
-Wall
- This enables warnings that are likely to indicate an error or undesired behavior, and that can easily be fixed.
-Wextra
- This enables extra warnings that are less likely to pose a problem, but that may still be wanted.
-Weverything
- Enables literally every warning.
The following warnings are actual warning flags; with each
description, the corresponding warning flag is included. Note that each of
these flag also has a negation (for example,
-Wcharmap-redef
enables the warning that
-Wno-charmap-redef
disables). Only the non-default
flag is listed here. Ignoring the “no-” prefix, entries are
listed alphabetically.
-Wno-assert
- Warn when
WARN
-type assertions fail. (See “Aborting the assembly process” in rgbasm(5) forASSERT
). -Wbackwards-for
- Warn when
FOR
loops have their start and stop values switched according to the step value. This warning is enabled by-Wall
. -Wbuiltin-args
- Warn about incorrect arguments to built-in functions, such as
STRSUB
() with indexes outside of the string's bounds. This warning is enabled by-Wall
. -Wcharmap-redef
- Warn when re-defining a charmap mapping. This warning is enabled by
-Wall
. -Wdiv
- Warn when dividing the smallest negative integer (-2**31) by -1, which yields itself due to integer overflow.
-Wempty-macro-arg
- Warn when a macro argument is empty. This warning is enabled by
-Wextra
. -Wempty-strrpl
- Warn when
STRRPL
() is called with an empty string as its second argument (the substring to replace). This warning is enabled by-Wall
. -Wlarge-constant
- Warn when a constant too large to fit in a signed 32-bit integer is
encountered. This warning is enabled by
-Wall
. -Wlong-string
- Warn when a string too long to fit in internal buffers is encountered.
This warning is enabled by
-Wall
. -Wmacro-shift
- Warn when shifting macro arguments past their limits. This warning is
enabled by
-Wextra
. -Wno-obsolete
- Warn when obsolete constructs such as the
_PI
constant orPRINTT
directive are encountered. -Wnumeric-string=
- Warn when a multi-character string is treated as a number.
-Wnumeric-string=0
or-Wno-numeric-string
disables this warning.-Wnumeric-string=1
or just-Wnumeric-string
warns about strings longer than four characters, since four or fewer characters fit within a 32-bit integer.-Wnumeric-string=2
warns about any multi-character string. -Wshift
- Warn when shifting right a negative value. Use a division by 2**N instead.
-Wshift-amount
- Warn when a shift's operand is negative or greater than 32.
-Wtruncation=
- Warn when an implicit truncation (for example,
db
to an 8-bit value) loses some bits.-Wtruncation=0
or-Wno-truncation
disables this warning.-Wtruncation=1
warns when an N-bit value's absolute value is 2**N or greater.-Wtruncation=2
or just-Wtruncation
also warns when an N-bit value is less than -2**(N-1), which will not fit in two's complement encoding. -Wunmapped-char=
- Warn when a character goes through charmap conversion but has no defined
mapping.
-Wunmapped-char=0
or-Wunmapped-char
disables this warning.-Wunmapped-char=1
or just-Wunmapped-char
only warns if the active charmap is not empty.-Wunmapped-char=2
warns if the active charmap is empty, and/or is not the default charmap ‘main’. -Wno-user
- Warn when the
WARN
built-in is executed. (See “Aborting the assembly process” in rgbasm(5) forWARN
).
EXAMPLES
You can assemble a source file in two ways.
Straightforward way:
$ rgbasm -o bar.o
foo.asm
Pipes way:
$ cat foo.asm | rgbasm -o bar.o
-
$ rgbasm -o bar.o - <
foo.asm
The resulting object file is not yet a usable ROM image—it must first be run through rgblink(1) and then rgbfix(1).
BUGS
Please report bugs on GitHub.
SEE ALSO
rgbasm(5), rgbfix(1), rgblink(1), rgbds(5), rgbds(7), gbz80(7)
HISTORY
rgbasm
was originally written by Carsten
Sørensen as part of the ASMotor package, and was later packaged in
RGBDS by Justin Lloyd. It is now maintained by a number of contributors at
https://github.com/gbdev/rgbds.