Hybrid bzImage and UEFI binaries (such as wimboot) include a bzImage
header within a section starting at offset zero, with the PE header
effectively occupying unused space within this section. This section
should not appear as a named section in the resulting PE file.
Allow for the existence of hidden sections that do not result in a
section header being written to the PE file.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Hybrid 32-bit BIOS and 64-bit UEFI binaries (such as wimboot) may
include R_X86_64_32 relocation records for the 32-bit BIOS portions.
These should be ignored when generating PE relocation records, since
they apply only to code that cannot be executed within the context of
the 64-bit UEFI binary, and creating a 4-byte relocation record is
invalid in a binary that may be relocated anywhere within the 64-bit
address space (see commit 907cffb "[efi] Disallow R_X86_64_32
relocations").
Add a "--hybrid" option to elf2efi, which will cause R_X86_64_32
relocation records to be silently discarded.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Hybrid bzImage and UEFI binaries (such as wimboot) require the PE
header to be kept as small as possible, since the bzImage header
starts at a fixed offset 0x1f1.
The EFI_IMAGE_OPTIONAL_HEADER structures in PeImage.h define an
optional header containing 16 data directory entries, of which the
last eight are unused in binaries that we create. Shrink the data
directory to contain only the first eight entries, to minimise the
overall size of the PE header.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Hybrid bzImage and UEFI binaries (such as wimboot) require the PE
header to be kept as small as possible, since the bzImage header
starts at a fixed offset 0x1f1.
The PE header currently includes 128 bytes of zero padding between the
DOS and NT header portions. This padding has been present since
commit 81d92c6 ("[efi] Add EFI image format and basic runtime
environment") first added support for EFI images in iPXE, and was
included on the basis of matching the observed behaviour of the
Microsoft toolchain. There appears to be no requirement for this
padding to exist: EDK2 binaries built with gcc include only 64 bytes
of zero padding, Linux kernel binaries include 66 bytes of non-zero
padding, and wimboot binaries include no padding at all.
Remove the unnecessary padding between the DOS and NT header portions
to minimise the overall size of the PE header.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
We cannot rely on the EDK2 ProcessorBind.h headers when compiling a
binary for execution on the build host itself (e.g. elf2efi), since
the host's CPU architecture may not even be supported by EDK2.
Fix by skipping ProcessorBind.h when building a host binary, and
defining the bare minimum required to allow other EDK2 headers to
compile cleanly.
Reported-by: Michal Suchánek <msuchanek@suse.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
As of commit f1e9e2b ("[efi] Align EFI image sections by page size"),
the VirtualSize fields for the .reloc and .debug sections have been
rounded up to the (4kB) image alignment. This breaks the PE
relocation logic in the UEFI shim, which requires the VirtualSize
field to exactly match the size as recorded in the data directory.
Fix by setting the VirtualSize field to the unaligned size of the
section, as is already done for normal PE sections (i.e. those other
than .reloc and .debug).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
As of commit f1e9e2b ("[efi] Align EFI image sections by page size"),
our SectionAlignment has been increased to 4kB in order to allow for
page-level memory protection to be applied by the UEFI firmware, with
FileAlignment left at 32 bytes.
The PE specification states that the value for FileAlignment "should
be a power of 2 between 512 and 64k, inclusive", and that "if the
SectionAlignment is less than the architecture's page size, then
FileAlignment must match SectionAlignment".
Testing shows that signtool.exe will reject binaries where
FileAlignment is less than 512, unless FileAlignment is equal to
SectionAlignment. This indicates a somewhat zealous interpretation of
the word "should" in the PE specification.
Work around this interpretation by increasing FileAlignment from 32
bytes to 512 bytes, and add explanatory comments for both
FileAlignment and SectionAlignment.
Debugged-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
After a PE image is fully loaded and relocated, the loader code may
opt to zero discardable sections for security reasons. This includes
relocation and debug information, as both contain hints about specific
locations within the binary. Mark both generated sections as
discardable, which follows the PE specification.
Signed-off-by: Marvin Häuser <mhaeuser@posteo.de>
For optimal memory permission management, PE sections need to be
aligned by the platform's minimum page size. Currently, the PE
section alignment is fixed to 32 bytes, which is below the typical 4kB
page size. Align all sections to 4kB and adjust ELF to PE image
conversion accordingly.
Signed-off-by: Marvin Häuser <mhaeuser@posteo.de>
The elf.h on FreeBSD defines ELF_R_TYPE and ELF_R_SYM (based on the
host platform) and omits some but not all of the AArch64 relocation
types.
Fix by undefining ELF_R_TYPE and ELF_R_SYM in favour of our own
definitions, and by placing each potentially missing relocation type
within an individual #ifdef guard.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The WORKAROUND_CFLAGS list is constructed based on running tests on
the target compiler, and the results may not be valid for the host
compiler.
The only relevant workaround required for the host compiler is
-Wno-stringop-truncation, which is needed to avoid a spurious compiler
warning for a totally correct usage of strncpy() in util/elf2efi.c.
Duplicating the workaround tests for the host compiler is messy, as is
conditionally applying __attribute__((nonstring)). Fix instead by
disapplying WORKAROUND_CFLAGS for the host compiler, and using
memcpy() with an explicitly calculated length instead of strncpy() in
util/elf2efi.c.
Reported-by: Ignat Korchagin <ignat@cloudflare.com>
Reported-by: Christopher Clark <christopher.w.clark@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Starting from binutils 2.31.0 (commit bd7ab16b) x86-64 assembler
generates R_X86_64_PLT32 instead of R_X86_64_PC32.
Acked-by: John Jolly <jjolly@suse.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The relocation type R_ARM_REL32 is generated when building
bin-arm32-efi/snp.efi using gcc 6.3 and ld 2.28.
R_ARM_REL32 is a program counter (PC) relative 32 bit relocation so we
can ignore it like all other PC relative relocations.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Relocation type R_ARM_V4BX requires no computation. It marks the
location of an ARMv4 branch exchange instruction.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The x86_64 EDK2 headers include a #pragma to mark all subsequent
symbol declarations and references as hidden if position-independent
code is being generated. Since libgen.h is currently included only
after the EDK2 headers, this results in __xpg_basename() being
erroneously marked as having hidden visibility (if the compiler
defaults to building position-independent code); this eventually
results in a failure to link the elf2efi binary.
Fix by including libgen.h prior to including the EDK2 headers.
Originally-fixed-by: Doug Goldstein <cardoe@cardoe.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Parse the intermediate ELF file directly instead of using libbfd, in
order to allow for cross-compiled ELF objects.
As a side bonus, this eliminates libbfd as a build requirement.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The Microsoft PE/COFF specification defines the MajorLinkerVersion and
MinorLinkerVersion fields as "The linker major version number" and
"The linker minor version number" respectively, and has nothing more
to say on the matter. These fields have no significance: they do not
affect the interpretation of the remainder of the file, but merely
provide diagnostic information for interested humans to read.
Apparently, versions 2.4 and earlier of the Microsoft linker produced
binaries so incorrigibly cursed that even to attempt to parse such a
binary would risk summoning a plague of enraged spiders. To protect
users from unwanted arachnids, ImageHlp.dll's MapAndLoad() function
will helpfully fail to map and/or load a 32-bit binary unless the
linker version field indicates version 2.5 or later. (64-bit binaries
are exempt from such helpfulness.)
Work around the broken Microsoft ImageHlp.dll library by providing a
linker version number that will satisfy the arbitrary whims of the
MapAndLoad() function.
This mirrors wimboot commit 670c7e2 ("[efi] Work around broken 32-bit
PE executable parsing in ImageHlp.dll").
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Avoid dragging in unnecessary iPXE header files such as <ipxe/uuid.h>
and <ipxe/tables.h> when building host utilities, and ensure that
FILE_LICENCE() (present in the imported EDK2 headers) expands to a
no-op.
Reported-by: Michael Tautschnig <mt@debian.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The debug directory size specified in the data directory should cover
only the EFI_IMAGE_DEBUG_DIRECTORY_ENTRY structure, not the whole of
the .debug section.
Reported-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
At some point in the past few years, binutils became more aggressive
at removing unused symbols. To function as a symbol requirement, a
relocation record must now be in a section marked with @progbits and
must not be in a section which gets discarded during the link (either
via --gc-sections or via /DISCARD/).
Update REQUIRE_SYMBOL() to generate relocation records meeting these
criteria. To minimise the impact upon the final binary size, we use
existing symbols (specified via the REQUIRING_SYMBOL() macro) as the
relocation targets where possible. We use R_386_NONE or R_X86_64_NONE
relocation types to prevent any actual unwanted relocation taking
place. Where no suitable symbol exists for REQUIRING_SYMBOL() (such
as in config.c), the macro PROVIDE_REQUIRING_SYMBOL() can be used to
generate a one-byte-long symbol to act as the relocation target.
If there are versions of binutils for which this approach fails, then
the fallback will probably involve killing off REQUEST_SYMBOL(),
redefining REQUIRE_SYMBOL() to use the current definition of
REQUEST_SYMBOL(), and postprocessing the linked ELF file with
something along the lines of "nm -u | wc -l" to check that there are
no undefined symbols remaining.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
UEFI binaries may be relocated to any location within the 64-bit
address space. We compile as position-independent code with hidden
visibility, which should force all relocation records to be either
PC-relative (in which case no PE relocations are required) or full
64-bit relocations. There should be no R_X86_64_32 relocation
records, since that would imply an invalid assumption that code could
not be relocated above 4GB.
Remove support for R_X86_64_32 relocation records from util/elf2efi.c,
so that any such records result in a build failure rather than a
potential runtime failure.
Reported-by: Jan Kundrát <jkt@kde.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Newer versions of bfd.h require definitions for the PACKAGE and
PACKAGE_VERSION macros used by autotools. Work around this by
manually defining these macros before including bfd.h.
Originally-fixed-by: Brandon Penglase <bpenglase-ipxe@spaceservices.net>
Tested-by: Brandon Penglase <bpenglase-ipxe@spaceservices.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Authenticode requires that the size of the raw file must equal the
size of the OptionalHeader.SizeOfHeaders plus the sum of all sections'
SizeOfRawData.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Currently, if elf2efi.c is compiled using a 32-bit HOST_CC, then the
resulting elf2efi64 binary will generate 32-bit EFI binaries instead
of 64-bit EFI binaries.
The problem is that elf2efi.c uses the MDE_CPU_* definitions to decide
whether to output a 32-bit or 64-bit PE binary. However, MDE_CPU_*
gets defined in ProcessorBind.h, depending on the compiler's target
architecture. Overriding them on the command line doesn't work in the
expected way, and you can end up in cases where both MDE_CPU_IA32 and
MDE_CPU_X64 are defined.
Fix by using a separate definition, EFI_TARGET_IA32/EFI_TARGET_X64,
which is specified only on the command line.
Signed-off-by: Geoff Lywood <glywood@vmware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Currently, if you attempt to build 64-bit EFI binaries on a 32-bit
system without a suitable cross-compiling version of libbfd, the iPXE
build will die with a segmentation fault in elf2efi64.
Fix by properly handling the return value from bfd_check_format().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain. Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.
Also update README, LOG and COPYRIGHTS to remove obsolete information.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
elf2efi converts a suitable ELF executable (containing relocation
information, and with appropriate virtual addresses) into an EFI
executable. It is less tightly coupled with the gPXE build process
and, in particular, does not require the use of a hand-crafted PE
image header in efiprefix.S.
elf2efi correctly handles .bss sections, which significantly reduces
the size of the gPXE EFI executable.
Michael Brown
Xiaotian Wu
Marvin Häuser
Christian Hesse
Heinrich Schuchardt
Geoff Lywood
Michael Brown