NetBoot/vasm-1/doc/output_aout.texi

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2020-06-20 01:33:04 +00:00
This chapter describes the a.out output module which can be
selected with the @option{-Faout} option.
@section Legal
This module is written in 2008-2012 by Frank Wille and
is covered by the vasm copyright without modifications.
@section Additional options for this module
@table @option
@item -mid=<machine id>
Sets the MID field of the a.out header to the specified value.
The MID defaults to 2 (Sun020 big-endian) for M68k and to 100
(PC386 little-endian) for x86.
@end table
@section General
This output module outputs the @code{a.out} (assembler output)
format, which is an older 32-bit format for Unix-like operating systems,
originally invented by AT&T.
@section Restrictions
The @code{a.out} output format, as implemented in vasm, currently supports
the following architectures:
@itemize @minus
@item M68k
@item i386
@end itemize
The following standard relocations are supported by default:
@itemize @minus
@item absolute, 8, 16, 32 bits
@item pc-relative, 8, 16, 32 bits
@item base-relative
@end itemize
Standard relocations occupy 8 bytes and don't include an addend, so they
are not suitable for most RISC CPUs. The extended relocations format occupies
12 bytes and also allows more relocation types.
@section Known Problems
Some known problems of this module at the moment:
@itemize @minus
@item Support for stab debugging symbols is still missing.
@item The extended relocation format is not supported.
@end itemize
@section Error Messages
This module has the following error messages:
@itemize @minus
@item 3004: section attributes <attr> not supported
@item 3008: output module doesn't allow multiple sections of the same type
@item 3010: section <%s>: alignment padding (%lu) not a multiple of %lu at 0x%llx
@end itemize