mirror of
https://github.com/elliotnunn/NetBoot.git
synced 2024-09-06 17:54:25 +00:00
485 lines
17 KiB
Plaintext
485 lines
17 KiB
Plaintext
This chapter describes the module-independent part of the assembler. It
|
|
documents the options and extensions which are not specific to a certain
|
|
target, syntax or output driver. Be sure to also read the chapters on the
|
|
backend, syntax- and output-module you are using. They will
|
|
likely contain important additional information like data-representation
|
|
or additional options.
|
|
|
|
@node General Assembler Options
|
|
@section General Assembler Options
|
|
|
|
@command{vasm} is run using the following syntax:
|
|
|
|
@example
|
|
@command{vasm<target>_<syntax> [options] file}
|
|
@end example
|
|
|
|
The following options are supported by the machine independent part
|
|
of @command{vasm}:
|
|
|
|
@table @option
|
|
|
|
@item -chklabels
|
|
Issues a warning when a label matches a mnemonic or directive name
|
|
in either upper or lower case.
|
|
|
|
@item -D<name>[=expression]
|
|
Defines a symbol with the name <name> and assigns the value of the
|
|
expression when given. The assigned value defaults to 1 otherwise.
|
|
|
|
@item -depend=<type>
|
|
Print all dependencies while assembling the source with the given
|
|
options. No output is generated. <type> may be @option{list} for
|
|
printing one file name in each new line, or @option{make} for printing
|
|
a sequence of file names on a single line, suitable for Makefiles.
|
|
When the output file name is given by @option{-o} then
|
|
@command{vasm} will also print @code{outname:} in front of it.
|
|
Note that unlike with @option{-dependall} only relative include
|
|
file dependencies will be listed (which is the common case).
|
|
|
|
@item -dependall=<type>
|
|
Prints dependencies in the same way as @option{-depend}, but
|
|
will also print all include files with absolute paths.
|
|
|
|
@item -depfile <filename>
|
|
Used together with @option{-depend} or @option{-dependall} and
|
|
instructs vasm to output all dependencies to a new file, instead
|
|
of stdout. Code will be generated in parallel to the dependencies
|
|
output.
|
|
|
|
@item -dwarf[=<version>]
|
|
Automatically generate DWARF debugging sections, suitable for
|
|
source level debugging. When the version specification is missing
|
|
DWARF V3 will be generated. The only difference to V2 is that it
|
|
creates a @code{.debug_ranges} section, with address ranges for all
|
|
sections, instead of a bad workaround by specifying
|
|
@code{DW_AT_low_pc=0} and @code{DW_AT_high_pc=~0}.
|
|
Note that when you build vasm from source, you may have to specify
|
|
your host operating system with @code{-Dname} in the Makefile to
|
|
include the appropriate code which can determine the current
|
|
work directory. Otherwise, the default would be to set the current
|
|
work directory to an empty string. Currently supported are:
|
|
@code{UNIX}, @code{AMIGA}, @code{ATARI}, @code{MSDOS},
|
|
@code{_WIN32}.
|
|
|
|
@item -esc
|
|
Enable escape character sequences. This will make vasm treat the
|
|
escape character \ in string constants similar as in the C language.
|
|
|
|
@item -F<fmt>
|
|
Use module <fmt> as output driver. See the chapter on output
|
|
drivers for available formats and options.
|
|
|
|
@item -I<path>
|
|
Define another include path. They are searched in the order of
|
|
occurence on the command line.
|
|
|
|
@item -ignore-mult-inc
|
|
When the same file is included multiple times with the same path
|
|
this is silently ignored, causing the file to be processed only
|
|
once. Note that you can still include the same file twice when
|
|
using different paths to access it.
|
|
|
|
@item -L <listfile>
|
|
Enables generation of a listing file and directs the output into
|
|
the file <listfile>.
|
|
|
|
@item -Ll<lines>
|
|
Set the number of lines per listing file page to <lines>.
|
|
|
|
@item -Lnf
|
|
Do not emit any form feed code into the listing file, for starting
|
|
a new page.
|
|
|
|
@item -Lns
|
|
Do not include symbols in the listing file.
|
|
|
|
@item -maxerrors=<n>
|
|
Defines the maximum number of errors to display before assembly
|
|
is aborted. When <n> is 0 then there is no limit. Defaults to 5.
|
|
|
|
@item -maxmacrecurs=<n>
|
|
Defines the maximum of number of recursions within a macro.
|
|
Defaults to 1000.
|
|
|
|
@item -nocase
|
|
Disables case-sensitivity for everything - identifiers, directives
|
|
and instructions. Note that directives and instructions may already
|
|
be case-insensitive by default in some modules.
|
|
|
|
@item -noesc
|
|
No escape character sequences. This will make vasm treat the
|
|
escape character \ as any other character. Might be useful for
|
|
compatibility.
|
|
|
|
@item -noialign
|
|
Perform no automatic alignment for instructions. Note that
|
|
unaligned instructions make your code crash when executed!
|
|
Only set when you know what you do!
|
|
|
|
@item -nosym
|
|
Strips all local symbols from the output file and doesn't include
|
|
any other symbols than those which are required for external
|
|
linkage.
|
|
|
|
@item -nowarn=<n>
|
|
Disable warning message <n>. <n> has to be the number of a valid
|
|
warning message, otherwise an error is generated.
|
|
|
|
@item -o <ofile>
|
|
Write the generated assembler output to <ofile> rather than
|
|
@file{a.out}.
|
|
|
|
@item -pad=<value>
|
|
The given padding value can be one of multiple bytes (up to the
|
|
cpu-backend's address size). It is used for alignment purposes
|
|
and to fill gaps between absolute @code{ORG} sections in the
|
|
binary output module. Defaults to a zero-byte.
|
|
|
|
@item -pic
|
|
Try to generate position independant code. Every relocation is
|
|
flagged by an error message.
|
|
|
|
@item -quiet
|
|
Do not print the copyright notice and the final statistics.
|
|
|
|
@item -unnamed-sections
|
|
Sections are no longer distinguished by their name, but only by
|
|
their attributes. This has the effect that when defining a second
|
|
section with a different name but same attributes as a first one,
|
|
it will switch to the first, instead of starting a new section.
|
|
Is set automatically, when using an output-module which doesn't
|
|
support section names. For example: aout, tos, xfile.
|
|
|
|
@item -unsshift
|
|
The shift-right operator (@code{>>}) treats the value to shift as
|
|
unsigned, which has the effect that 0-bits are inserted on the
|
|
left side. The number of bits in a value depend on the target
|
|
address type (refer to the appropriate cpu module documentation).
|
|
|
|
@item -w
|
|
Hide all warning messages.
|
|
|
|
@item -wfail
|
|
The return code of vasm will no longer be 0 (success), when there
|
|
was a warning. Errors always make the return code fail.
|
|
|
|
@item -x
|
|
Show an error message, when referencing an undefined symbol.
|
|
The default behaviour is to declare this symbol as externally
|
|
defined.
|
|
|
|
@end table
|
|
|
|
Note that while most options allow an argument without any separating blank,
|
|
some others require it (e.g. @option{-o} and @option{-L}).
|
|
|
|
@section Expressions
|
|
|
|
Standard expressions are usually evaluated by the main part of vasm
|
|
rather than by one of the modules (unless this is necessary).
|
|
|
|
All expressions evaluated by the frontend are calculated in terms
|
|
of target address values, i.e. the range depends on the backend.
|
|
|
|
The available operators include all those which are common in assembler as
|
|
well as in C expressions.
|
|
|
|
C like operators:
|
|
@itemize
|
|
@item Unary: @code{+ - ! ~}
|
|
@item Arithmetic: @code{+ - * / % << >>}
|
|
@item Bitwise: @code{& | ^}
|
|
@item Logical: @code{&& ||}
|
|
@item Comparative: @code{< > <= >= == !=}
|
|
@end itemize
|
|
|
|
Assembler like operators:
|
|
@itemize
|
|
@item Unary: @code{+ - ~}
|
|
@item Arithmetic: @code{+ - * / // << >>}
|
|
@item Bitwise: @code{& ! ~}
|
|
@item Comparative: @code{< > <= >= = <>}
|
|
@end itemize
|
|
|
|
Up to version 1.4b the operators had the same precedence and associativity as
|
|
in the C language. Newer versions have changed the operator priorities to
|
|
comply with the common assembler behaviour. The expression evaluation
|
|
priorities, from highest to lowest, are:
|
|
|
|
@enumerate 1
|
|
@item @code{+ - ! ~} (unary +/- sign, not, complement)
|
|
@item @code{<< >>} (shift left, shift right)
|
|
@item @code{&} (bitwise and)
|
|
@item @code{^ ~} (bitwise exclusive-or)
|
|
@item @code{| !} (bitwise inclusive-or)
|
|
@item @code{* / % //} (multiply, divide, modulo)
|
|
@item @code{+ -} (plus, minus)
|
|
@item @code{< > <= >=} (less, greater, less or equal, greater or equal)
|
|
@item @code{== != = <>} (equality, inequality)
|
|
@item @code{&&} (logical and)
|
|
@item @code{||} (logical or)
|
|
@end enumerate
|
|
|
|
Operands are integral values of the target address type. They can either be
|
|
specified as integer constants of different bases (see the documentation
|
|
on the syntax module to see how the base is specified) or character
|
|
constants. Character constants are introduced by @code{'} or @code{"}
|
|
and have to be terminated by the same character that started them.
|
|
|
|
Multiple characters are allowed and a constant is built according to the
|
|
endianess of the target.
|
|
|
|
When the @option{-esc} option was specified, or automatically enabled by
|
|
a syntax module, vasm interprets escape character sequences as in the
|
|
C language:
|
|
|
|
@table @code
|
|
|
|
@item \\
|
|
Produces a single @code{\}.
|
|
|
|
@item \b
|
|
The bell character.
|
|
|
|
@item \f
|
|
Form feed.
|
|
|
|
@item \n
|
|
Line feed.
|
|
|
|
@item \r
|
|
Carriage return.
|
|
|
|
@item \t
|
|
Tabulator.
|
|
|
|
@item \"
|
|
Produces a single @code{"}.
|
|
|
|
@item \'
|
|
Produces a single @code{'}.
|
|
|
|
@item \e
|
|
Escape character (27).
|
|
|
|
@item \<octal-digits>
|
|
One character with the code specified by the digits
|
|
as octal value.
|
|
|
|
@item \x<hexadecimal-digits>
|
|
One character with the code specified by the digits
|
|
as hexadecimal value.
|
|
|
|
@item \X<hexadecimal-digits>
|
|
Same as @code{\x}.
|
|
|
|
@end table
|
|
|
|
Note, that the default behaviour of vasm has changed since V1.7! Escape
|
|
sequence handling has been the default in older versions. This has been
|
|
changed to increase compatibility with other assemblers. Use @option{-esc}
|
|
to assemble sources with escape character sequences. It is still the
|
|
default in the @code{std} syntax module, though.
|
|
|
|
@section Symbols
|
|
|
|
You can define as many symbols as your available memory permits. A symbol
|
|
may have any length and can be of global or local scope. Internally, there
|
|
are three types of symbols:
|
|
@table @code
|
|
@item Expression
|
|
These symbols are usually not visible outside the
|
|
source, unless they are explicitely exported.
|
|
@item Label
|
|
Labels are always addresses inside a program section. By
|
|
default they have local scope for the linker.
|
|
@item Imported
|
|
These symbols are externally defined and must be
|
|
resolved by the linker.
|
|
@end table
|
|
|
|
Beginning with vasm V1.5c one expression symbol is always defined to allow
|
|
conditional assembly depending on the assembler being used: @code{__VASM}.
|
|
Its value depends on the selected cpu module. There may be other symbols which
|
|
are pre-defined by the syntax- or by the cpu module.
|
|
|
|
@section Include Files
|
|
|
|
Vasm supports include files and defining include paths. Whether this
|
|
functionality is available depends on the syntax module, which has to
|
|
provide the appropriate directives.
|
|
|
|
On startup vasm will define at least one default include path: the
|
|
current working directory, where the assembler program was launched from.
|
|
When the input file is loaded from a different directory, i.e. the input
|
|
file is a relative or absolute path and not a single file name, then the
|
|
path to the input file name will be added as another include path.
|
|
|
|
Include paths are searched in the following order:
|
|
@enumerate 1
|
|
@item Current work directory.
|
|
@item Paths specified by @option{-I} in the order of occurence on the
|
|
command line.
|
|
@item Path to the input source file.
|
|
@item Paths specified by directives inside the source text (in the order
|
|
of occurence).
|
|
@end enumerate
|
|
|
|
@section Macros
|
|
|
|
Macros are supported by vasm, but the directives for defining them have
|
|
to be implemented in the syntax module. The assembler core supports 9
|
|
macro arguments by default to be passed in the operand field,
|
|
which can be extended to any number by the syntax module.
|
|
They can be referenced inside the macro either by name (@code{\name}) or by
|
|
number (@code{\1} to @code{\9}), or both, depending on the syntax module.
|
|
Recursions and early exits are supported.
|
|
|
|
Refer to the selected syntax module for more details.
|
|
|
|
@section Structures
|
|
|
|
Vasm supports structures, but the directives for defining them
|
|
have to be implemented in the syntax module.
|
|
|
|
@section Conditional Assembly
|
|
|
|
Has to be provided completely by the syntax module.
|
|
|
|
@section Known Problems
|
|
|
|
Some known module-independent problems of @command{vasm} at the moment:
|
|
|
|
@itemize @minus
|
|
|
|
@item None.
|
|
|
|
@end itemize
|
|
|
|
@section Credits
|
|
|
|
All those who wrote parts of the @command{vasm} distribution, made suggestions,
|
|
answered my questions, tested @command{vasm}, reported errors or were otherwise
|
|
involved in the development of @command{vasm} (in descending alphabetical order,
|
|
under work, not complete):
|
|
|
|
@itemize
|
|
@item Jordan Zebor
|
|
@item Joseph Zatarski
|
|
@item Frank Wille
|
|
@item Jim Westfall
|
|
@item Jens Sch"onfeld
|
|
@item Henryk Richter
|
|
@item Sebastian Pachuta
|
|
@item Esben Norby
|
|
@item Gunther Nikl
|
|
@item George Nakos
|
|
@item Timm S. Mueller
|
|
@item Gareth Morris
|
|
@item Dominic Morris
|
|
@item Garry Marshall
|
|
@item Jean-Paul Mari
|
|
@item Mauricio Mu@~noz Lucero
|
|
@item J@"org van de Loo
|
|
@item Robert Leffmann
|
|
@item Andreas Larsson
|
|
@item Miro Kropacek
|
|
@item Olav Kr"omeke
|
|
@item Mikael Kalms
|
|
@item Mark Jones
|
|
@item Bert Jahn
|
|
@item Daniel Illgen
|
|
@item Matthew Hey
|
|
@item Philippe Guichardon
|
|
@item Romain Giot
|
|
@item Francois Galea
|
|
@item Tom Duin
|
|
@item Fernando Cabrera
|
|
@item Patrick Bricout
|
|
@item Karoly Balogh
|
|
@end itemize
|
|
|
|
@section Error Messages
|
|
|
|
The frontend has the following error messages:
|
|
|
|
@itemize @minus
|
|
@item 1: illegal operand types
|
|
@item 2: unknown mnemonic <%s>
|
|
@item 3: unknown section <%s>
|
|
@item 4: no current section specified
|
|
@item 5: internal error %d in line %d of %s
|
|
@item 6: symbol <%s> redefined
|
|
@item 7: %c expected
|
|
@item 8: cannot resolve section <%s>, maximum number of passes reached
|
|
@item 9: instruction not supported on selected architecture
|
|
@item 10: number or identifier expected
|
|
@item 11: could not initialize %s module
|
|
@item 12: multiple input files
|
|
@item 13: could not open <%s> for input
|
|
@item 14: could not open <%s> for output
|
|
@item 15: unknown option <%s>
|
|
@item 16: no input file specified
|
|
@item 17: could not initialize output module <%s>
|
|
@item 18: out of memory
|
|
@item 19: symbol <%s> recursively defined
|
|
@item 20: fail: %s
|
|
@item 21: section offset is lower than current pc
|
|
@item 22: target data type overflow (%d bits)
|
|
@item 23: undefined symbol <%s>
|
|
@item 24: trailing garbage after option -%c
|
|
@item 25: missing pacro parameters
|
|
@item 26: missing end directive for macro "%s"
|
|
@item 27: macro definition inside macro "%s"
|
|
@item 28: maximum number of %d macro arguments exceeded
|
|
@item 29: option %s was specified twice
|
|
@item 30: read error on <%s>
|
|
@item 31: expression must be constant
|
|
@item 32: initialized data in bss
|
|
@item 33: missing end directive in repeat-block
|
|
@item 34: #%d is not a valid warning message
|
|
@item 35: relocation not allowed
|
|
@item 36: illegal escape sequence \%c
|
|
@item 37: no current macro to exit
|
|
@item 38: internal symbol %s redefined by user
|
|
@item 39: illegal relocation
|
|
@item 40: label name conflicts with mnemonic
|
|
@item 41: label name conflicts with directive
|
|
@item 42: division by zero
|
|
@item 43: illegal macro argument
|
|
@item 44: reloc org is already set
|
|
@item 45: reloc org was not set
|
|
@item 46: address space overflow
|
|
@item 47: bad file-offset argument
|
|
@item 48: assertion "%s" failed: %s
|
|
@item 49: cannot declare structure within structure
|
|
@item 50: no structure
|
|
@item 51: instruction has been auto-aligned
|
|
@item 52: macro name conflicts with mnemonic
|
|
@item 53: macro name conflicts with directive
|
|
@item 54: non-relocatable expression in equate <%s>
|
|
@item 55: initialized data in offset section
|
|
@item 56: illegal structure recursion
|
|
@item 57: maximum number of macro recursions (%d) reached
|
|
@item 58: data has been auto-aligned
|
|
@item 59: register symbol <%s> redefined
|
|
@item 60: cannot evaluate constant huge integer expression
|
|
@item 61: cannot evaluate floating point expression
|
|
@item 62: imported symbol <%s> was not referenced
|
|
@item 63: symbol <%s> already defined with %s scope
|
|
@item 64: unexpected "else" without "if"
|
|
@item 65: unexpected "endif" without "if"
|
|
@item 66: maximum if-nesting depth exceeded (%d levels)
|
|
@item 67: "endif" missing for conditional block started at %s line %d
|
|
@item 68: repeatedly defined symbol <%s>
|
|
@item 69: macro <%s> does not exist
|
|
@item 70: register <%s> does not exist
|
|
@item 71: register symbol <%s> has wrong type
|
|
@item 72: cannot mix positional and keyword arguments
|
|
@item 73: undefined macro argument name
|
|
@item 74: required macro argument %d was left out
|
|
@item 75: label <%s> redefined
|
|
|
|
@end itemize
|