Parsing ELF data is simpler if we don't have to build a single binary
to handle both 32-bit and 64-bit ELF formats.
Allow for separate 32-bit and 64-bit binaries built from util/zbin.c
(as is already done for util/elf2efi.c).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Expose the effective carry (or borrow) out flag from big integer
addition and subtraction, and use this to elide an explicit bit test
when performing x25519 reduction.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Every architecture uses the same implementation for bigint_is_set(),
and there is no reason to suspect that a future CPU architecture will
provide a more efficient way to implement this operation.
Simplify the code by providing a single architecture-independent
implementation of bigint_is_set().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The big integer shift operations are misleadingly described as
rotations since the original x86 implementations are essentially
trivial loops around the relevant rotate-through-carry instruction.
The overall operation performed is a shift rather than a rotation.
Update the function names and descriptions to reflect this.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
An n-bit multiplication product may be added to up to two n-bit
integers without exceeding the range of a (2n)-bit integer:
(2^n - 1)*(2^n - 1) + (2^n - 1) + (2^n - 1) = 2^(2n) - 1
Exploit this to perform big integer multiplication in constant time
without requiring the caller to provide temporary carry space.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
All consumers of profile_timestamp() currently treat the value as an
unsigned long. Only the elapsed number of ticks is ever relevant: the
absolute value of the timestamp is not used. Profiling is used to
measure short durations that are generally fewer than a million CPU
cycles, for which an unsigned long is easily large enough.
Standardise the return type of profile_timestamp() as unsigned long
across all CPU architectures. This allows 32-bit architectures such
as i386 and riscv32 to omit all logic associated with retrieving the
upper 32 bits of the 64-bit hardware counter, which simplifies the
code and allows riscv32 and riscv64 to share the same implementation.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Big integer multiplication currently performs immediate carry
propagation from each step of the long multiplication, relying on the
fact that the overall result has a known maximum value to minimise the
number of carries performed without ever needing to explicitly check
against the result buffer size.
This is not a constant-time algorithm, since the number of carries
performed will be a function of the input values. We could make it
constant-time by always continuing to propagate the carry until
reaching the end of the result buffer, but this would introduce a
large number of redundant zero carries.
Require callers of bigint_multiply() to provide a temporary carry
storage buffer, of the same size as the result buffer. This allows
the carry-out from the accumulation of each double-element product to
be accumulated in the temporary carry space, and then added in via a
single call to bigint_add() after the multiplication is complete.
Since the structure of big integer multiplication is identical across
all current CPU architectures, provide a single shared implementation
of bigint_multiply(). The architecture-specific operation then
becomes the multiplication of two big integer elements and the
accumulation of the double-element product.
Note that any intermediate carry arising from accumulating the lower
half of the double-element product may be added to the upper half of
the double-element product without risk of overflow, since the result
of multiplying two n-bit integers can never have all n bits set in its
upper half. This simplifies the carry calculations for architectures
such as RISC-V and LoongArch64 that do not have a carry flag.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
As of commit 79c0173 ("[build] Create util/genfsimg for building
filesystem-based images"), the EFI boot file name for each CPU
architecture is defined within the genfsimg script itself, rather than
being passed in as a Makefile parameter.
Remove the now-redundant Makefile definitions for EFI_BOOT_FILE.
Reported-by: Christian I. Nilsson <nikize@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The definitions of the setjmp() and longjmp() functions are common to
all architectures, with only the definition of the jump buffer
structure being architecture-specific.
Move the architecture-specific portions to bits/setjmp.h and provide a
common setjmp.h for the function definitions.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Move the <gdbmach.h> file to <bits/gdbmach.h>, and provide a common
dummy implementation for all architectures that have not yet
implemented support for GDB.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Big integer multiplication is currently used only as part of modular
exponentiation, where both multiplicand and multiplier will be the
same size.
Relax this requirement to allow for the use of big integer
multiplication in other contexts.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Over the years, the undocumented operand modifier used to produce the
unprefixed constant values in __einfo_error() has varied from "%c0" to
"%a0" in commit 1a77466 ("[build] Fix use of inline assembly on GCC
4.8 ARM64 builds") and back to "%c0" in commit 3fb3ffc ("[build] Fix
use of inline assembly on GCC 8 ARM64 builds"), according to the
evolving demands of the toolchain.
LoongArch64 suffers from a similar issue: GCC 13 will allow either,
but the currently released GCC 12 allows only the "%a0" form.
Introduce a macro ASM_NO_PREFIX, defined in bits/compiler.h, to
abstract away this difference and allow different architectures to use
different operand modifiers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add support for building as a Linux userspace binary for AArch64.
This allows the self-test suite to be more easily run for the 64-bit
ARM code. For example:
# On a native AArch64 system:
#
make bin-arm64-efi/tests.linux && ./bin-arm64-efi/tests.linux
# On a non-AArch64 system (e.g. x86_64) via cross-compilation,
# assuming that kernel and glibc headers are present within
# /usr/aarch64-linux-gnu/sys-root/:
#
make bin-arm64-linux/tests.linux CROSS=aarch64-linux-gnu- && \
qemu-aarch64 -L /usr/aarch64-linux-gnu/sys-root/ \
./bin-arm64-linux/tests.linux
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Move the platform-specific DHCP client architecture definitions to
header files of the form <ipxe/$(PLATFORM)/dhcparch.h>. This
simplifies the directory structure and allows the otherwise unused
arch/$(ARCH)/include/$(PLATFORM) to be removed from the include
directory search path, which avoids the confusing situation in which a
header file may potentially be accessed through more than one path.
For Linux userspace binaries on any architecture, use the EFI values
for that architecture by delegating to the EFI header file. This
avoids the need to explicitly select values for Linux userspace
binaries for each architecture.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Several distributions include versions of gcc that are patched to
create position-independent executables by default. These have caused
multiple problems over the years: see e.g. commits fe61f6d ("[build]
Fix compilation when gcc is patched to default to -fPIE -Wl,-pie"),
5de1346 ("[build] Apply the "-fno-PIE -nopie" workaround only to i386
builds"), 7c395b0 ("[build] Use -no-pie on newer versions of gcc"),
and decee20 ("[build] Disable position-independent code for ARM64 EFI
builds").
The build system currently attempts to work around these mildly broken
patched versions of gcc for the i386 and arm64 architectures. This
misses the relatively obscure bin-x86_64-pcbios build platform, which
turns out to also require the same workaround.
Attempt to preempt the next such required workaround by moving the
existing i386 version to apply to all platforms and all architectures,
unless -fpie has been requested explicitly by another Makefile (as is
done by arch/x86_64/Makefile.efi).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some versions of gcc (observed with the cross-compiling gcc 9.3.0 in
Ubuntu 20.04) default to enabling -fPIE. Experimentation shows that
this results in the emission of R_AARCH64_ADR_GOT_PAGE relocation
records for __stack_chk_guard. These relocation types are not
supported by elf2efi.c.
Fix by explicitly disabling position-independent code for ARM64 EFI
builds.
Debugged-by: Antony Messerli <antony@mes.ser.li>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The -mabi option was added in GCC 4.9. Test for the existence of this
option to allow for building with earlier versions of GCC.
Reported-by: Benjamin S. Allen <bsallen@alcf.anl.gov>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The vendor class identifier strings in DHCP_ARCH_VENDOR_CLASS_ID are
out of sync with the (correct) client architecture values in
DHCP_ARCH_CLIENT_ARCHITECTURE.
Fix by removing all definitions of DHCP_ARCH_VENDOR_CLASS_ID, and
instead generating the vendor class identifier string automatically
based on DHCP_ARCH_CLIENT_ARCHITECTURE and DHCP_ARCH_CLIENT_NDI.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
DHCPv4 and DHCPv6 share some values in common for the architecture-
specific options (such as the client system architecture type), but
use different encapsulations: DHCPv4 has a single byte for the option
length while DHCPv6 has a 16-bit field for the option length.
Move the containing DHCP_OPTION() and related wrappers from the
individual dhcp_arch.h files to dhcp.c, thus allowing for the
architecture-specific values to be reused in dhcpv6.c.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The raw cycle counter at PMCCNTR_EL0 works in qemu but seems to always
read as zero on physical hardware (tested on Juno r1 and Cavium
ThunderX), even after ensuring that PMCR_EL0.E and PMCNTENSET_EL0.C
are both enabled.
Use CNTVCT_EL0 instead; this seems to count at a lower resolution
(tens of CPU cycles), but is usable for profiling.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
