binutils-gdb/ld
Andre Vieira 2c9d089c90 arm, objdump: Make objdump use bfd's machine detection to drive disassembly
For any arm elf target, disable an old piece of code that forced disassembly to
disassemble for 'unknown architecture' which once upon a time meant it would
disassemble ANY arm instruction.  This is no longer true with the addition of
Armv8.1-M Mainline, as there are conflicting encodings for different thumb
instructions.

BFD however can detect what architecture the object file was assembled for
using information in the notes section.  So if available, we use that,
otherwise we default to the old 'unknown' behaviour.

With the changes above code, a mode changing 'bx lr' assembled for armv4 with
the option --fix-v4bx will result in an object file that is recognized by bfd
as one for the armv4 architecture.  The disassembler now disassembles this
encoding as a BX even for Armv4 architectures, but warns the user when
disassembling for Armv4 that this instruction is only valid from Armv4T
onwards.

Remove the unused and wrongfully defined ARM_ARCH_V8A_CRC, and
define and use a ARM_ARCH_V8R_CRC to make sure instructions enabled by
-march=armv8-r+crc are disassembled correctly.

Patch up some of the tests cases, see a brief explanation for each below.

inst.d:
This test checks the assembly & disassembly of basic instructions in armv3m. I
changed the expected behaviour for teqp, cmnp cmpp and testp instructions to
properly print p when disassembling, whereas before, in the 'unknown' case it
would disassemble these as UNPREDICTABLE as they were changed in later
architectures.

nops.d:
Was missing an -march, added one to make sure we were testing the right
behavior of NOP<c> instructions.

unpredictable.d:
Was missing an -march, added armv6 as that reproduced the behaviour being
tested.
2024-11-08 10:06:38 +00:00
..
emulparams
emultempl
po
scripttempl
testsuite arm, objdump: Make objdump use bfd's machine detection to drive disassembly 2024-11-08 10:06:38 +00:00
.gitignore
aclocal.m4
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config.in
configure
configure.ac
configure.host
configure.tgt
deffile.h
deffilep.y
dep-in.sed
elf-hints-local.h
fdl.texi
gen-doc.texi
genscrba.sh
genscripts.sh
h8-doc.texi
ld.h
ld.texi
ldbuildid.c
ldbuildid.h
ldcref.c
ldctor.c
ldctor.h
ldelf.c
ldelf.h
ldelfgen.c
ldelfgen.h
ldemul.c
ldemul.h
ldexp.c
ldexp.h
ldfile.c
ldfile.h
ldgram.y
ldint.texi
ldlang.c
ldlang.h
ldlex-wrapper.c
ldlex.h
ldlex.l
ldmain.c
ldmain.h
ldmisc.c
ldmisc.h
ldver.c
ldver.h
ldwrite.c
ldwrite.h
lexsup.c
libdep_plugin.c
MAINTAINERS
Makefile.am
Makefile.in
mri.c
mri.h
NEWS
pdb.c
pdb.h
pe-dll.c
pe-dll.h
pep-dll-aarch64.c
pep-dll-x86_64.c
pep-dll.c
pep-dll.h
plugin.c
plugin.h
README
sysdep.h
testplug2.c
testplug3.c
testplug4.c
testplug.c
TODO

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		README for LD

This is the GNU linker.  It is distributed with other "binary
utilities" which should be in ../binutils.  See ../binutils/README for
more general notes, including where to send bug reports.

There are many features of the linker:

* The linker uses a Binary File Descriptor library (../bfd)
  that it uses to read and write object files.  This helps
  insulate the linker itself from the format of object files.

* The linker supports a number of different object file
  formats.  It can even handle multiple formats at once:
  Read two input formats and write a third.

* The linker can be configured for cross-linking.

* The linker supports a control language.

* There is a user manual (ld.texi), as well as the
  beginnings of an internals manual (ldint.texi).

Installation
============

See ../binutils/README.

If you want to make a cross-linker, you may want to specify
a different search path of -lfoo libraries than the default.
You can do this by setting the LIB_PATH variable in ./Makefile
or using the --with-lib-path configure switch.

To build just the linker, make the target all-ld from the top level
directory (one directory above this one).

Porting to a new target
=======================

See the ldint.texi manual.

Reporting bugs etc
===========================

See ../binutils/README.

Known problems
==============

The Solaris linker normally exports all dynamic symbols from an
executable.  The GNU linker does not do this by default.  This is
because the GNU linker tries to present the same interface for all
similar targets (in this case, all native ELF targets).  This does not
matter for normal programs, but it can make a difference for programs
which try to dlopen an executable, such as PERL or Tcl.  You can make
the GNU linker export all dynamic symbols with the -E or
--export-dynamic command line option.

HP/UX 9.01 has a shell bug that causes the linker scripts to be
generated incorrectly.  The symptom of this appears to be "fatal error
- scanner input buffer overflow" error messages.  There are various
workarounds to this:
  * Build and install bash, and build with "make SHELL=bash".
  * Update to a version of HP/UX with a working shell (e.g., 9.05).
  * Replace "(. ${srcdir}/scripttempl/${SCRIPT_NAME}.sc)" in
    genscripts.sh with "sh ${srcdir}..." (no parens) and make sure the
    emulparams script used exports any shell variables it sets.

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