Instead of having a GCC specific routine to perform self-relocation
based on ELF metadata, use the PE/COFF metadata and the existing
PeCoff library routines. This reduces the amount of bespoke assembler
code that is a burden to maintain, and is not portable across the set
of toolchains we support.
This does require some special care, as we have no control over how
the C code references global symbols, so we need to emit these
references from the calling assembler code. Otherwise, they may be
emitted as absolute references, in which case they need to be fixed
up themselves, leading to a circular dependency.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Sami Mujawar <Sami.Mujawar@arm.com>
In some cases, the CLANG38 toolchain profile in LTO mode emits GOT
based relocations in spite of our attempts to avoid this, by using
hidden visibility, -Bsymbolic etc.
On AARCH64, we managed to work around this by processing the GOT
based relocations in GenFw. As it turns out, the same issue exists
on 32-bit ARM, but unfortunately, we cannot use a similar trick to
get rid of the GOT entry, and the relocation metadata is insufficient
to locate the GOT entry in the binary.
Note that in this particular case, we are interested in PIE linking
only (i.e., producing a .rela section containing dynamic relocations
that the startup code can process directly), and not in position
independent code generation, and by passing the -pie option to the
linker directly using -Wl,-pie (and dropping -shared), we can coerce
the GOLD linker into doing only the former rather than both when it
performs its LTO code generation.
Acked-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
The PcdCoreCount dependency in the "ArmVirtPrePiUniCoreRelocatable.inf"
file is false; the module doesn't consume the PCD. Clean up the INF.
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Julien Grall <julien.grall@linaro.org>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
The self-relocating PrePi module that is used by the ArmVirtQemuKernel
and ArmVirtXen targets runs the linker in PIE mode so that it emits
dynamic relocations into the final image in a way that permits the
module to relocate itself into place before calling into the C code.
When building these targets using the CLANG38 toolchain, we switch
from the BFD to the GOLD linker, which behaves a bit differently when
building PIE executables, and insists on emitting GOT indirected symbol
references throughout, which means a) that we end up with absolute
addresses (which need to be fixed up at load time) for no good reason,
and b) we have to add support for handling GOT entries to GenFw if we
want to convert them into PE/COFF.
So instead, let's emit a shared library. Since the ELF image only serves
as the input to GenFw, this does not lead to any loss of functionality,
although it does require the -Bsymbolic linker option to be added to
ensure that no symbol based dynamic relocations are emitted (which
would, e.g., permit lazy binding for shared libraries). So for all
other toolchains, the linker option changes are a no-op.
Then, we have to convince CLANG38/GOLD that there is no need to refer
to symbols via a GOT entry. This is done by forcing hidden visibility
for all symbols in all components that make up the PrePi SEC module:
this informs the linker that a symbol is never exported or preempted,
making it safe to refer to it directly from anywhere in the code,
rather than indirectly via a GOT entry.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Derive the size of the GCD memory space map directly from the CPU's
information registers rather than from the PcdPrePiCpuMemorySize PCD,
which will be removed.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Among other things, the header file declares the ArchInitialize()
function, which is called from "PrePi.c", and implemented (dependent on
architecture) in "AArch64/ArchPrePi.c" and "Arm/ArchPrePi.c".
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Julien Grall <julien.grall@linaro.org>
Suggested-by: Michael Kinney <michael.d.kinney@intel.com>
Ref: http://mid.mail-archive.com/E92EE9817A31E24EB0585FDF735412F56327F7D3@ORSMSX113.amr.corp.intel.com
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
The PrePi code we inherited from ArmPlatformPkg contains a rather
obscure optimization, where entry points of the PE/COFF and LZMA
handling routines are recorded in special HOBs, allowing DXE core
to call into that code directly rather than carry its own copy of
these libraries.
Given that no ArmVirtPkg platforms actually include the library
resolutions* that take advantage of these optimizations, let's not
bother with them, and remove the associated code.
* EmbeddedPkg/Library/LzmaHobCustomDecompressLib/LzmaHobCustomDecompressLib.inf
EmbeddedPkg/Library/DxeHobPeCoffLib/DxeHobPeCoffLib.inf
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>
PrePi doesn't use anything defined by this package so drop the bogus
dependency.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
ArmPlatformStackLib has hooks into primary/secondary core PCDs and
other ArmPlatformLib related junk, so let's simply set the stack
pointer directly. This is trivial given that our PrePi is unicore
only.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Remove the pointless dependency on ArmPlatformLib: none of the code we
call from it actually does anything useful.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
ArmVirtQemuKernel and ArmVirtXen use essentially the same code to
retrieve DRAM information from the DT /memory node at early boot,
and invoke it via the ArmPlatformPeiBootAction () hook exposed by
ArmPlatformLib. Let's move this code into the PrePi implementation
these platforms share between them (and not with any other platforms)
so we can eliminate another dependency on the messy ArmPlatformLib.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>
To accommodate upcoming GCCx toolchain versions that require 'gcc' to
be used as the linker in order to support LTO, switch GCC44 and later
(including CLANG35) to a new DLINK build rule that invokes 'gcc' as the
linker instead of 'ld'. Since gcc expects its command line arguments in
a different format, and expects arguments that it needs to pass to the
linker to be prefixed with '-Wl,', this involves changes to most of the
DLINK_FLAGS definitions in tools_def.template, as well as some changes to
module .INF files that set their own linker options.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
This adds support to the self relocating PrePi instance that is built
as a PIE ET_DYN executable. It primarily involves porting the relocation
routine to use ELF32 REL entries instead of ELF64 RELA entries which is
what AArch64 uses.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19331 6f19259b-4bc3-4df7-8a09-765794883524
Now that we dropped all ArmPlatformGlobalVariableLib dependencies,
there is no longer a need to allocate and clear out the global
variable region in the PrePi init code. So remove it.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18991 6f19259b-4bc3-4df7-8a09-765794883524
Ard Biesheuvel
Ard Biesheuvel
Michael D Kinney
Laszlo Ersek
Olivier Martin