- Make it actually work
- Split text/data/reloc/rodata sections
- Move hash sections to past end of image
(un-needed in PE)
- Correct section & file alignment
- Correct image size
- rename .reloc to .areloc within ELF
as only on ARM32 does this name cause
it to be marked as REL and subsequently
mistakenly added to RELSZ
Builds correctly & tested working in QEMU
Signed-off-by: Callum Farmer <gmbr3@opensuse.org>
This makes setup and teardown functions defined with
__attribute__((__constructor__) and __attribute__((__destructor__)) work
in normal circumstances in EFI binaries.
A couple of notes:
- it implements both the old-style .ctors/.dtors methods and the newer
style .init_array/.fini_array ELF constructor and destructor arrays,
processed in the order:
.init_array[]
.ctors[]
efi_main()
.dtors[]
.fini_array[]
- Destructors will only be called if efi_main() exits using "return";
any call to Exit() will still longjmp() past them.
- InitializeLib() has already been called before constructors run, so
they don't need to call it (and neither does anything else.) For
compatibility, it has been altered so calling it more than once is
safe.
- No attempt is made to handle any constructor or destructor with a
prototype other than "void func(void);", but note that InitializeLib
has been called, so LibImageHandle, ST, BS, and RT are set.
- The init_array/ctor/dtor/fini_array lists aren't the using the GNU
"CONSTRUCTOR" output section command, so they don't start with a size.
- The lists are individually sorted during the link stage via
SORT_BY_NAME() in the linker script.
- The default (empty) init_array/ctor/dtor/fini_array lists are padded
out to 8-byte alignment with ".p2align 3, 0", and each list always has
at least one ".long 0" at the end of it (even if it's completely
empty). As a result, they can have NULLs that need to be skipped.
The sections they're in are mergeable, so the NULLs don't have to be
exclusively at the end.
- The ia64 and mips64el arches have not been tested.
Signed-off-by: Peter Jones <pjones@redhat.com>
Objcopy sometimes generates .rela.plt and .rela.data
sections for which their names are longer than the 8
characters limit of PE32
Signed-off-by: Callum Farmer <gmbr3@opensuse.org>
Some newer versions of binutils can set invalid COMMONPAGESIZE
and MAXPAGESIZE values on these architectures
Signed-off-by: Callum Farmer <gmbr3@opensuse.org>
Use ld commands DATA_SEGMENT_ALIGN and DATA_SEGMENT_END
Fixes binutils 2.39 warning:
/usr/bin/ld: warning: efi/fwup.so has a LOAD segment with RWX
permissions
Signed-off-by: Callum Farmer <gmbr3@opensuse.org>
decide to stick stuff we don't explicitly mention at 0,
no matter what else has already explicitly been located there.
A debian/ubuntu builder noted:
gcc -O0 -g3 -fpic -Wall -fshort-wchar -fno-strict-aliasing \
-fno-merge-constants -ffreestanding -fno-stack-protector \
-fno-stack-check --std=c11 -DCONFIG_aarch64 -D__KERNEL__ \
-I/usr/include/efi/ -I/usr/include/efi/aarch64/ \
-iquote/«PKGBUILDDIR»/include "-DDEBUGDIR=L\"/\"" \
-ffreestanding -I/usr/lib/gcc/aarch64-linux-gnu/4.9/include \
-c -o fakeesrt2.o fakeesrt2.c
ld -nostdlib --warn-common --no-undefined --fatal-warnings -shared \
-Bsymbolic -L/usr/lib -L/usr/lib --build-id=sha1 \
/usr/lib/crt0-efi-aarch64.o --defsym=EFI_SUBSYSTEM=0xa \
-o fakeesrt2.so fakeesrt2.o -lefi -lgnuefi \
/usr/lib/gcc/aarch64-linux-gnu/4.9/libgcc.a \
-T elf_aarch64_efi.lds
ld: section .note.gnu.build-id loaded at [00000000,00000023] overlaps section .text loaded at [00000000,0000668f]
This shouldn't be a problem if we explicitly tell it where to put them.
Ard added a patch to do this on Arm and aarch64 targets in 16409cad4cb,
but it needs to be everywhere.
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Nigel Croxon <nigel.croxon@hpe.com>
On arm, the linker script is missing section collection for data and
bss. This causes some symbols (notably static array symbols) not to
get relocated correctly and the resulting efi binary to crash. Fix
this by correctly collecting all the data and bss sections.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Nigel Croxon <nigel.croxon@hpe.com>
Subject: [PATCH] Add ARM .note.gnu.build-id input section to
a dedicated output section
This fixes the builds for ARM and AARCH64, which currently fail at link
time with an error like this:
arm-linux-gnueabi-ld: section .note.gnu.build-id loaded at
[0000000000000000,0000000000000023] overlaps section .text loaded at
[0000000000000000,00000000000064cf]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Nigel Croxon <nigel.croxon@hpe.com>
all of our linker scripts:
_text
_etext
_text_size
_data
_edata
_data_size
There are various things that are slightly different (positions of
.rela*, .dynamic, and similar in relation to .data), but _text and _data
are now always at the beginning of their respective sections with regard
to how a debuger would reference the debug info, and _etext and _edata
are now always extant and guaranteed to be after any of the respective
kind of data the debugger would look for in that section.
This also adds an application example of how it might be used, and a
makefile target for %.efi.debug which will generate a separate debuginfo
file for that example.
This also enables debugging by default (i.e. -g is in CFLAGS) and adds
.note.gnu.build-id sections to our .so files (i.e. --build-id=sha1 is in
LDFLAGS).
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Nigel Croxon <nigel.croxon@hp.com>
