Greg Ungerer [Thu, 4 Oct 2012 02:32:38 +0000 (02:32 +0000)]
From: Larry Baker <baker@usgs.gov>
The _stack_start symbol needs to be in the same flatmem memory region
as text/data/bss, otherwise it will not end up with the correct address.
Direct the section into the flatmem region.
The GNU linker uses -v as a shortcut to --version, not --verbose. So atm,
if you run `ld -v` to get the linker version, ld-elf2flt throws out a lot
of verbose debugging information. So drop the -v checking in ld-elf2flt
to keep from breaking systems that parse the linker version.
David McCullough [Thu, 16 Dec 2010 01:37:41 +0000 (01:37 +0000)]
The .note.ABI-tag section exists to indicate to other projects (like gdb
or library loaders) information about the target OS. It doesn't actually
contain anything that is used at runtime. So while the current linker
script gathers this into the .data section, the final FLAT doesn't include
anything from it. But tools expect to find a dedicated section in ELFs
which the current section merge prevents.^M
So give .note.ABI-tag its own output section so gdb can locate and use it.
This shouldn't change the FLAT files produced in any way.
David McCullough [Tue, 17 Aug 2010 04:25:26 +0000 (04:25 +0000)]
When we converted ld-elf2flt from the shell script to C, one small nuance
was missed: argv[0] contains the full path only when invoked with the full
path. This is not the same behavior for shell scripts as $0 is always the
full path to the script in question. Most of the time this isn't an issue
as gcc will invoke all of its tools (like the linker) with a full relative
path to itself. However, if we attempt to invoke the linker directly, we
can see misbehavior such as:
bfin-uclinux-ld.real: cannot open linker script file ./../lib/elf2flt.ld:
No such file or directory
So, to fix this, we lean on more libiberty functions. Specifically, the
make_relative_prefix() function. This function locates a full argv[0] by
scanning $PATH to see where it was invoked. This might sound a little
dodgy, but this is fundamental to how gcc and binutils implement support
for their runtime relocation, so it can't break ld-elf2flt without first
breaking every one else ;).
In the fall out of this fix, we can cull a bunch of local code that does
custom path parsing. So not only do we get to fix an annoying bug, we get
to shrink code in the process.
Signed-off-by: Steve Kilbane <steve@whitecrow.demon.co.uk> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
David McCullough [Tue, 22 Jun 2010 06:12:47 +0000 (06:12 +0000)]
The current code misses checking a few args in order to determine the
default "print" mode (ktrace/l1stack/...). Rather than update a list
that people easily forget, rework the code to generically detect that
no arguments have been specified.
The bflt loader in the kernel will, however, add a small extra data table
just before .data's content (cf. handling of MAX_SHARED_LIBS in
binfmt_flat.c:load_flat_file).
Now, if .text and .data are in the same segment, directly following each
other in the binary file, but have that extra data table added in the
run-time memory layout, GDB will get very confused when trying to access
items in the now-moved .data section. Without any kernel (loader) / GDB
changes, the solution is to tell the linker to always put .text and .data
into separate segments, which GDB will handle gracefully then.
Poor getopt() implementations as found in many BSD/Darwin systems will
stop processing options after a non-option is encountered. That means
ld-elf2flt has to be careful to not stick options after non-options when
executing sub children. In a default setup, it will invoke `elf2flt` with
the output followed by the -a option which subsequently fails:
elf2flt: Can't open '-a': No such file or directory
David McCullough [Tue, 14 Jul 2009 23:00:33 +0000 (23:00 +0000)]
the "all" target should not be depending on "ld-elf2flt"
anymore as this is handled through the PROG vars. it isnt a problem
for Linux systems, but when EXEEXT is set, things go boom.
David McCullough [Sun, 12 Jul 2009 23:28:58 +0000 (23:28 +0000)]
Due to shell portability issues (which is to say shell scripts are not
portable -- think Windows), convert elf2flt to C code.
I've updated this code base to the latest elf2flt tree and actually done
some basic tests -- building the three Blackfin tuples (ELF, FLAT, FDPIC)
and running programs on my Blackfin boards. This process found errors in
the original implementation as well as some of the cleanups I did.
Signed-off-by: Nathan Sidwell <nathan@codesourcery.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Unify the duplicated windows and other system fallback logic in stubs.h
and add some fatal() helper functions to standardize the error output when
falling over. This way we don't end up with obscure error messages with
no idea what util they are coming from.
This cleans up the Makefile handling of the different compiler flags such
that it uses standard names across the board as well as unifies the link
method.
Rather than putting the `rm` at the end of the script before the normal
exit point, create a trap to automatically delete the script when exiting.
This way the linker script gets cleaned up whenever there is an error as
well. Otherwise every link invocation that ends in a failure could leave
behind crap. On my system, i found almost 2 million of these suckers in
my /tmp dir.
David McCullough [Sun, 24 May 2009 23:33:48 +0000 (23:33 +0000)]
When the relocs are larger than 16bits, incorrect values are written when
the .H/.L loading are reversed. Normally this wouldn't happen because the
gcc compiler always outputs in the same order (first hi, then lo).
Signed-off-by: Jie Zhang <jie.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
David McCullough [Sun, 17 May 2009 23:14:54 +0000 (23:14 +0000)]
The header logic for pulling in ELF defines mixes common ELF headers and
target specific headers. In the Blackfin case, we always want to pull in
the bfin.h since most of the time, the common ELF headers do not have our
relocation defines. This fixes building for mingw targets.
The FLAT structure is all built on 32bit types, so make sure the elf2flt
code uses 32bit types rather than long's. This way we get correct
behavior when the host sizeof(long) is not 32bit as is on all 64bit
systems nowadays.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
GCC properly provides CTOR/DTOR END/LIST symbols already via the normal
crtbegin and crtend objects. Since it's been doing this for a while, add
a configure option to control the manual list found in the elf2flt linker
script and default it to off now.
Often build systems will use -shared when creating shared libraries, so
don't barf on the flag when we see it. This makes porting efforts easier.
As a sanity check, make sure we see the -shared-lib-id flag when creating
a shared library.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Some arches (like the Blackfin architecture) have an ABI where all symbols
get a symbol prefix. In our case, it's an underscore ("_"). So we set the
symbol prefix in the configure script and output it in the linker script and
all relevant files.
David McCullough [Thu, 27 Nov 2008 12:20:48 +0000 (12:20 +0000)]
When compiled with CVS binutils, busybox fails to execute properly.
That's because it's using --gc-sections, and the elf2flt linker script
allows the linker to remove parts of the .init and .fini sections. This
patch fixes it.
David McCullough [Thu, 27 Nov 2008 01:08:04 +0000 (01:08 +0000)]
Kazu Hirata wrote:
> Attached is a patch to fix elf2flt.ld so that C++ programs will link
> successfully.
>
> Nathan Sidwell says:
> nathan@codesourcery.com
>
> "The problem is the .eh_frame_hdr optimization. firstly that input
> section was not mentioned in the linker script and secondly, the
> linker requires .eh_frame_hdr and .eh_frame section in the output,
> so it can optimize them. I move gcc_except_table out of .data, for
> consistency."
I've been trying to get CVS binutils up and running on the Blackfin, and
after debugging a C++ link failure I eventually tracked it down to the
elf2flt linker script, and google pointed me at this thread which I'd
completely forgotten in the meantime. The patch is needed, please apply
to elf2flt.
David McCullough [Fri, 21 Nov 2008 11:35:07 +0000 (11:35 +0000)]
It is somewhat common for people to use the -s (strip) option to the
compiler when linking. Currently this breaks FLAT generation. There's no
real reason that I can see that we would bother keeping this, so just filter
it out to make compatibility / ease of use nicer.
We should link against -lc before any of the binutils libs (libiberty/bfd)
as those libs provide replacements for some common functions we don't really
care about (like getopt). Otherwise, if the C library does something wacky
in its API (like renaming symbols), we get a desync where some symbols are
provided by the binutils libs while others are provided by the C library.
For a concrete example, try building elf2flt on OS X 10.5. Their stupid
headers do this in unistd.h:
when debugging a flat loader problem involving relocs, i found it very
useful to compare what the loader was trying to do with what relocs
were actually in the binary
to that end, i add a '-P' flag to flthdr that will dump all the reloc
information found in a flat binary.
David McCullough [Wed, 29 Oct 2008 11:38:34 +0000 (11:38 +0000)]
Reserve a flag for the blackfin target (FLAT_FLAG_L1STK), no other platform
will use it, but for now we have plenty of bits left and we can always
re-use it later if needed.
David McCullough [Thu, 13 Mar 2008 04:38:28 +0000 (04:38 +0000)]
I'm lazy and having to set 4 configure options when I could just set 1 is a
pain. So --with-binutils-build-dir allows you to set the base tree of the
compiled binutils directory and will setup reasonable defaults for the flags
(if they haven't already been set):
David McCullough [Wed, 27 Feb 2008 11:41:32 +0000 (11:41 +0000)]
This patch allows elf2flt/flthdr's compression options to work in a wider
variety of environments (e.g. under MinGW/Win32), by linking with zlib
rather than by using external gzip/gunzip executables. The cp binary
isn't used any more either, and libiberty's make_temp_file() is used
instead of mkstemp() as a more portable way of creating a temporary file.
Also the compression logic is made somewhat clearer, IMO.
Signed-off-by: Julian Brown <julian@codesourcery.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
David McCullough [Sun, 24 Feb 2008 23:17:51 +0000 (23:17 +0000)]
When moving the xmalloc changes from the Blackfin elf2flt to the upstream
elf2flt repo, I accidentally dropped the libiberty.h include. Not a fatal
error, but having proper prototypes is always a good thing.
David McCullough [Thu, 21 Feb 2008 01:09:05 +0000 (01:09 +0000)]
I hit a random failure in elf2flt (not elf2flt's fault, I was screwing with
ELFs and LMAs/VMAs), but the resulting error message was useless:
malloc: Cannot allocate memory
Since I was executing `...-gcc` at the time, where exactly this error message
was coming from was hard to say. So instead of using malloc() and then doing
a simple 'perror("malloc"); exit(1);' in the elf2flt.c code, it'd be better
for everyone if we used the xmalloc() funcs from libiberty. We're already
linking elf2flt against libiberty, so there's no extra headers/libs to link
against.
Now the crash looks like:
bfin-uclinux-elf2flt: out of memory allocating 4221960244 bytes after a total of
135168 bytes
So much nicer! :)
This patch fixes two issues which are triggered when compiling for nios2:
* Typo in a goto label
* Misplaced switch statement which probably is left from an older revision.
David McCullough [Tue, 27 Nov 2007 22:51:30 +0000 (22:51 +0000)]
This patch is required to successfully link against libstdc++ on the Nios2
platform.
Signed-off-by: Atle Nissestad <atle@nissestad.no>
Also remove the duplicated data1 section and add the eh_frame_hdr section.
Source of these changes lost (sorry :-)
David McCullough [Thu, 11 Oct 2007 03:50:51 +0000 (03:50 +0000)]
the intl subdir in binutils may redirect some funcs with libintl_* prefixes
(like building for win32), so the attached patch adds a stub like the
existing one for dcgettect() ... this fixes building of elf2flt for me for
mingw targets
Greg Ungerer [Wed, 1 Aug 2007 03:40:12 +0000 (03:40 +0000)]
lf2flt crashes on Linux/amd64:
(gdb) run -a -o links -p links.gdb links.gdb
Starting program: /home/stsp/dslinux/toolchain/prefix/bin/arm-linux-elf-elf2flt -a -o links -p links.gdb links.gdb
Program received signal SIGSEGV, Segmentation fault.
_bfd_elf_canonicalize_reloc (abfd=<value optimized out>, section=0x5f6900,
relptr=0xffffffffa6360010, symbols=<value optimized out>)
at /home/stsp/dslinux/toolchain/src/binutils-2.17/bfd/elf.c:6367
6367 *relptr++ = tblptr++;
(gdb) bt
#0 _bfd_elf_canonicalize_reloc (abfd=<value optimized out>, section=0x5f6900,
relptr=0xffffffffa6360010, symbols=<value optimized out>)
at /home/stsp/dslinux/toolchain/src/binutils-2.17/bfd/elf.c:6367
#1 0x00000000004006dd in output_relocs (abs_bfd=0x5f5570,
symbols=0x2b30a5e99010, number_of_symbols=16585, n_relocs=0x7fff04c0fe58,
text=0x2b30a6102010 "", text_len=<value optimized out>, text_vma=0,
data=0x2b30a627b010 "", data_len=934480, data_vma=1541824,
rel_bfd=0x5f4400)
at /home/stsp/dslinux/toolchain/src/elf2flt-20051225/elf2flt.c:587
#2 0x0000000000401180 in main (argc=<value optimized out>,
argv=<value optimized out>)
at /home/stsp/dslinux/toolchain/src/elf2flt-20051225/elf2flt.c:1949
The problem seems to be that the one and only call to xmalloc()
in elf2flt.c does not return a valid pointer for some reason.
I'm wondering why xmalloc() is used exactly once in elf2flt.c.
All other heap allocations in elf2flt are done with plain malloc().
The attached patch fixes the segfault by replacing the call to xmalloc()
with a call to malloc(). It also makes elf2flt check for return
values of malloc() calls, providing the equivalent behaviour of
using xmalloc().
Patch submitted by Stefan Sperling <stsp@stsp.name>
David McCullough [Thu, 23 Nov 2006 22:42:07 +0000 (22:42 +0000)]
the install program is run with the '-s' option which makes `install` run the
host `strip` on the installed binary ... this certainly wont work when
cross-compiling and really, the standard is to leave stripping up to the
people doing the actual install
so attached patch simply drops the -s argument to install
as more-or-less definitive descriptions of how shared flat libraries
should be built and used. Please let me know if they aren't, and if
there's another recipe somewhere.
Anyway, the RFC is about two issues:
(1) Shared libraries usually have some symbols that are internally
STB_GLOBAL (because they are shared between more than one input
object) but which should nevertheless be treated as local to
the library as a whole; they shouldn't be exported to users
of the library. According to the article above, the usual
way to arrange this is to run:
objcopy -L <sym1> -L <sym2> ... foo.gdb
on the linked foo.gdb library. That certainly works, but
maintaining the list of symbols can be a bit cumbersome.
I think it would help a lot if ld-elf2flt automatically localised
symbols with hidden and internal visibility. This would allow
users to localise symbols in the library source code -- via gcc
attributes or assembly directives -- and would eliminate one
difference between shared flat libraries and shared ELF libraries.
If the library's source code hides all the appropriate symbols --
which the source code for many ELF-leaning libraries do, unless their
build system relies on something like "local:" directives in version
scripts -- then no separate -L list is needed.
(2) If a shared library and a user of a shared library both define
some symbol foo, you don't get a redefinition warning or error.
However, if the symbols are a different size, you _do_ get a warning
about that.
To me, this seems like the worst of both worlds. I can see cases
where the user would want to be told about any redefinition, and
would want a command-line option to enable that behaviour. That's
a separate issue that I'm not tackling here.
But when redefinitions are silently allowed, warning about changes
in size seems a little pointless. Shared flat libraries can't
really refer back to symbols defined by the user of the library
(such as the executable); all symbol references are resolved
when the library is statically linked. Shared flat libraries
act a lot like a restricted form of ELF -Bsymbolic libraries.
Thus having a different size of symbol S in shared library X and
user Y is very unlikely to be an issue unless the redefinition of
S is itself an issue. X is not going to refer directly to Y's
definition of S. And if you create, say, a shared C library that
includes all the C library functions needed by at least one
program on the system, it's likely that some programs will have
harmless symbol name clashes. For example, some programs might be
written with just standard C in mind, and use symbols that clash
with a POSIX, GNU or uClibc extension.
I think it would help if we weakened the exported symbols. This
would tell the linker that the symbols are only there if needed,
and that the user of the library is free to use the symbol for
something else. This wouldn't affect the redefinition diagnostic;
if that diagnostic is ever implemented, it should apply to both
global and weak symbols, because in both cases we'll have two
definitions of the same symbol.
Comments? Does this sound reasonable sane?
In case it does, the patch below implements both (1) and (2). (1) is
simple with CVS objcopy, which now has a --localize-hidden option:
Sadly, that option won't appear in an FSF release before 2.18, so I've
provided a fall-back that uses objdump and sed instead. (2) is easy
with the long-standing --weaken option.
FWIW, the patch has been tested fairly extensively on Coldfire with
shared C and C++ libraries, as well as with ad-hoc libraries. No
post-processing of these libraries was needed: you could just link with
ld-elf2flt and use the output directly.
I've tested both the --localize-hidden and fallback versions.
Richard
Signed-off-by: Richard Sandiford <richard@codesourcery.com>
David McCullough [Fri, 21 Jul 2006 13:11:04 +0000 (13:11 +0000)]
This patch adds elf2flt support for prioritised constructors and destructors,
but only when --enable-emit-relocs is in effect.
GCC puts prioritised constructors and destructors in special .ctor.N
and .dtor.N sections (where N encodes the priority). The constructors
and destructors in these sections have a lower priority than those
in the default .ctor and .dtor sections. However, we need to treat
the crtbegin.o's and crtend.o's sections specially; crtbegin.o's .[cd]tor
sections must come before all the other .[cd]tor* contents and crtend.o's
.[cd]tor sections must come after all other contents.
In --disable-emit-relocs links, it wasn't possible to treat crtbegin.o
and crtend.o specially. ld-elf2flt would do:
so all the input .[cd]tor sections would already be lumped together by the
time the script was used. This isn't a problem for --enable-emit-relocs as
it only links once.
The patch copies the [cd]tor support from the standard binutils linker
script. The question is: should the new lines be used unconditionally,
or only when --enable-emit-relocs is in effect?
We could use the new lines for --disable-emit-relocs without breaking
programs that don't use prioritised [cd]tors. However, it would be a user
interface regression for programs that _do_ use them. At the moment,
if you try to use prioritised [cd]tors with --disable-emit-relocs,
you get a linker error like this:
error: no memory region specified for loadable section `.ctors.60535'
With the new lines, the link would silently succeed, and you'd get a
runtime failure instead. I've therefore guarded the lines with
"SINGLE_LINK:", a bit like the "W_RODAT" stuff that's already there.
Tested on Coldfire, with both --enable-emit-relocs and
--disable-emit-relocs. It fixes the GCC ecos.exp tests.
Please install if OK.
Richard
Signed-off-by: Richard Sandiford <richard@codesourcery.com>
This patch adds m68k support for elf2flt -a. I've tested it with
load-to-RAM, -msep-data PIC-with-GOT and -mshared-library PIC-with-GOT.
Like ARM, but unlike V850, the new code errors out on relocs it doesn't
understand, rather than assuming that they're 32-bit fields.
It seems likely that every port that supports -a will want to print the
"reloc type not supported in this context" message; we've got two copies
already, and m68k would add a third. I've therefore moved the v850
"bad_v850_reloc_err:" code outside the #ifdef and renamed the label to
the more neutral "bad_resolved_reloc:". I've also changed the ARM code
to use this now-common code instead of its own copy.
In a similar vein, I've changed the default 32-bit field handling
so that it is the target of a new label, "good_32bit_resolved_reloc:".
The generic and v850 code can then jump to this code in their default
cases, while m68k can jump to it for R_68K_32 relocs.
The patch was written before Shaun Jackman made -p and -a work together:
I'd been using this hunk too, but as well as guarding:
q->address += got_size;
with "!use_resolved", I'd guarded the calculation of got_size itself,
as the value isn't otherwise used. I've kept this additional check
in the attached patch. Please apply if OK.
Signed-off-by: Richard Sandiford <richard@codesourcery.com>
projects / elf2flt.git / log