Recent versions of the GNU assembler (observed with GNU as 2.35 on
Fedora 33) will produce a warning message
Warning: no instruction mnemonic suffix given and no register
operands; using default for `bts'
The operand size affects only the potential range for the bit number.
Since we pass the bit number as an unsigned int, it is already
constrained to 32 bits for both i386 and x86_64.
Silence the assembler warning by specifying an explicit 32-bit operand
size (and thereby matching the choice that the assembler would
otherwise make automatically).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Assume that preservation of the %xmm registers is unnecessary during
installation of iPXE into memory, since this is an operation that by
its nature substantially disrupts large portions of the system anyway
(such as the E820 memory map). This assumption allows us to utilise
the existing CPUID code to check that FXSAVE/FXRSTOR are supported.
Test for support during the call to init_librm and store the flag for
use during subsequent calls to virt_call.
Reduce the scope of TIVOLI_VMM_WORKAROUND to affecting only the call
to check_fxsr(), to reduce #ifdef pollution in the remaining code.
Debugged-by: Johannes Heimansberg <git@jhe.dedyn.io>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The __asmcall declaration has no effect on a void function with no
parameters, but should be included for completeness since the function
is called directly from assembly code.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide a generic raw image prefix, which assumes that the iPXE image
has been loaded in its entirety on a paragraph boundary.
The resulting .raw image can be loaded via RPL using an rpld.conf file
such as:
HOST {
ethernet = 00:00:00:00:00:00/6;
FILE {
path="ipxe.raw";
load=0x2000;
};
execute=0x2000;
};
Debugged-by: Johannes Heimansberg <git@jhe.dedyn.io>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
A zero-length initrd file will currently cause an endless loop during
reshuffling as the empty image is repeatedly swapped with itself.
Fix by terminating the inner loop before considering an image as a
candidate to be swapped with itself.
Reported-by: Pico Mitchell <pico@randomapplications.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Split out the portions of cachedhcp.c that can be shared between BIOS
and UEFI (both of which can provide a buffer containing a previously
obtained DHCP packet, and neither of which provide a means to
determine the length of this DHCP packet).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some versions of GNU ld (observed with binutils 2.36 on Arch Linux)
introduce a .note.gnu.property section marked as loadable at a high
address and with non-empty contents. This adds approximately 128MB of
garbage to the BIOS .usb disk images.
Fix by using a custom linker script for the prefix-only binaries such
as the USB disk partition table and MBR, in order to allow unwanted
sections to be explicitly discarded.
Reported-by: Christian Hesse <mail@eworm.de>
Tested-by: Christian Hesse <mail@eworm.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The semantics of the assembler's .align directive vary by CPU
architecture. For the ARM builds, it specifies a power of two rather
than a number of bytes. This currently leads to the .einfo entries
(which do not appear in the final binary) having an alignment of 256
bytes for the ARM builds.
Fix by switching to the GNU-specific directive .balign, which is
consistent across architectures
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>
Add a few more ABSOLUTE() expressions to convince the FreeBSD linker
that already-absolute symbols are, in fact, absolute.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some versions of objcopy will spuriously complain when asked to
extract the .zinfo section since doing so will nominally alter the
load addresses of the (non-loadable) .bss.* sections.
Avoid these warnings by placing the .zinfo section at the very end of
the load memory address space.
Allocate non-overlapping load memory addresses for the (non-loadable)
.bss.* sections, in the hope of avoiding spurious warnings about
overlapping load addresses.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Consolidate the remaining logic common to initrd_init() and imgmem()
into a shared image_memory() function.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Generalise util/geniso, util/gensdsk, and util/genefidsk to create a
single script util/genfsimg that can be used to build either FAT
filesystem images or ISO images.
Extend the functionality to allow for building multi-architecture UEFI
bootable ISO images and combined BIOS+UEFI images.
For example:
./util/genfsimg -o combined.iso \
bin-x86_64-efi/ipxe.efi \
bin-arm64-efi/ipxe.efi \
bin/ipxe.lkrn
would generate a hybrid image that could be used as a CDROM (or hard
disk or USB key) on legacy BIOS, x86_64 UEFI, or ARM64 UEFI.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The malloc_dma() function allocates memory with specified physical
alignment, and is typically (though not exclusively) used to allocate
memory for DMA.
Rename to malloc_phys() to more closely match the functionality, and
to create name space for functions that specifically allocate and map
DMA-capable buffers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Define pci_ioremap() as a wrapper around ioremap() that could allow
for a non-zero address translation offset.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
This change fixes the offset used when retrieving the iPXE stack
pointer after a COM32 binary returns. The iPXE stack pointer is saved
at the top of the available memory then the the top of the stack for
the COM32 binary is set just below it. However seven more items are
pushed on the COM32 stack before the entry point is invoked so when
the COM32 binary returns the location of the iPXE stack pointer is 28
(and not 24) bytes above the current stack pointer.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
This caused iPXE to reject images even when enough memory was
available.
Signed-off-by: David Decotigny <ddecotig@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The only remaining use case in iPXE for the CPU direction flag is in
__memcpy_reverse() where it is set to allow the use of "rep movsb" to
perform the memory copy. This matches the equivalent functionality in
the EDK2 codebase, which has functions such as InternalMemCopyMem that
also temporarily set the direction flag in order to use "rep movsb".
As noted in commit d2fb317 ("[crypto] Avoid temporarily setting
direction flag in bigint_is_geq()"), some UEFI implementations are
known to have buggy interrupt handlers that may reboot the machine if
a timer interrupt happens to occur while the direction flag is set.
Work around these buggy UEFI implementations by using the
(unoptimised) generic_memcpy_reverse() on i386 or x86_64 UEFI
platforms.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The UEFI specification states that the calling convention for IA-32
and x64 includes "Direction flag in EFLAGS is clear". This
specification covers only the calling convention used at the point of
calling functions annotated with EFIAPI. The specification explicitly
states that other functions (such as private functions or static
library calls) are not required to follow the UEFI calling
conventions.
The reference EDK2 implementation follows this specification. In
particular, the EDK2 interrupt handlers will clear the direction flag
before calling any EFIAPI functions, and will restore the direction
flag when returning from the interrupt handler. Some EDK2 private
library functions (most notably InternalMemCopyMem) may set the
direction flag temporarily in order to make efficient use of CPU
string operations.
The current implementation of iPXE's bigint_is_geq() for i386 and
x86_64 will similarly set the direction flag temporarily in order to
make efficient use of CPU string operations.
On some UEFI implementations (observed with a Getac RX10 tablet), a
timer interrupt that happens to occur while the direction flag is set
will reboot the machine. This very strongly indicates that the UEFI
timer interrupt handler is failing to clear the direction flag before
performing an affected operation (such as copying a block of memory).
Work around such buggy UEFI implementations by rewriting
bigint_is_geq() to avoid the use of string operations and so obviate
the requirement to temporarily set the direction flag.
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>
Reduce the size of the USB disk image in the common case that
CONSOLE_INT13 is not enabled.
Originally-implemented-by: Romain Guyard <romain.guyard@mujin.co.jp>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
It is currently not possible to build the all-drivers iPXE binaries
for ARM, since there is no implementation for inb(), outb(), etc.
There is no common standard for accessing I/O space on ARM platforms,
and there are almost no ARM-compatible peripherals that actually
require I/O space accesses.
Provide dummy implementations that behave as though no device is
present (i.e. ignore writes, return all bits high for reads). This is
sufficient to allow the all-drivers binaries to link, and should cause
drivers to behave as though no I/O space peripherals are present in
the system.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
PCI Configuration Space contains fields prog-if at the offset 0x09,
sub-class at the offset 0x0a and base-class at the offset 0x0b (it
respects little endian). PCIR structure uses these fields in the same
order.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow the subsystem IDs to be used when checking for PXE stacks with
broken interrupt support.
Suggested-by: Levi Hsieh <Levi.Hsieh@dell.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Commit 6149e0a ("[librm] Provide symbols for inline code placed into
other sections") may cause build failures due to duplicate label names
if the compiler chooses to duplicate inline assembly code.
Fix by using the "%=" special format string to include a
guaranteed-unique number within the label name.
The "%=" will be expanded only if constraints exist for the inline
assembly. This fix therefore requires that all REAL_CODE() fragments
use a (possibly empty) constraint list.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide symbols constructed from the object name and line number for
code fragments placed into alternative sections, such as inline
REAL_CODE() assembly placed into .text16. This simplifies the
debugging task of finding the source code corresponding to a given
instruction pointer.
Note that we cannot use __FUNCTION__ since it is not a preprocessor
macro and so cannot be concatenated with string literals.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
If the underlying PXE stack reports an invalid IRQ number (above
IRQ_MAX), treat this as equivalent to an empty IRQ number and fall
back to using polling mode.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The existence of MMX and SSE is required by the System V x86_64 ABI
and so is assumed by gcc, but these registers are not preserved by our
own interrupt handlers and are unlikely to be preserved by other
context switch handlers in a boot firmware environment.
Explicitly prevent gcc from using MMX or SSE registers to avoid
potential problems due to silent register corruption.
We must remove the %xmm0-%xmm5 clobbers from the x86_64 version of
hv_call() since otherwise gcc will complain about unknown register
names. Theoretically, we should probably add code to explicitly
preserve the %xmm0-%xmm5 registers across a hypercall, in order to
guarantee to external code that these registers remain unchanged. In
practice this is difficult since SSE registers are disabled by
default: for background information see commits 71560d1 ("[librm]
Preserve FPU, MMX and SSE state across calls to virt_call()") and
dd9a14d ("[librm] Conditionalize the workaround for the Tivoli VMM's
SSE garbling").
Signed-off-by: Michael Brown <mcb30@ipxe.org>
We currently perform various min-entropy calculations using build-time
floating-point arithmetic. No floating-point code ends up in the
final binary, since the results are eventually converted to integers
and asserted to be compile-time constants.
Though this mechanism is undoubtedly cute, it inhibits us from using
"-mno-sse" to prevent the use of SSE registers by the compiler.
Fix by using fixed-point arithmetic instead.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow the ACPI power management timer to be used if enabled via
TIMER_ACPI in config/timer.h. This provides an alternative timer on
systems where the standard 8254 PIT is unavailable or unreliable.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When DEBUG=librm_mgmt is enabled, intercept CPU exceptions and provide
a register and stack dump, then drop to an emergency shell. Exiting
from the shell will almost certainly not work, but this provides an
opportunity to view the register and stack dump and carry out some
basic debugging.
Note that we can intercept only the first 8 CPU exceptions, since a
PXE ROM is not permitted to rebase the PIC.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Using "ld --oformat binary" for mbr.bin and usbdisk.bin seems to cause
segmentation faults on some versions of binutils (observed on Fedora
27). Work around this problem by using ld to create an intermediate
ELF object, followed by objcopy (via the existing %.tmp -> %.bin rule)
to create the final binary.
Note that we cannot simply use a single-stage "objcopy -O binary"
since this will not process the relocation records for x86_64: see
commit 1afcccd ("[build] Do not use "objcopy -O binary" for objects
with relocation records").
Reported-by: Brent S <bts@square-r00t.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add missing FILE_LICENCE declarations to x86_64 headers based on the
corresponding i386 headers (from which the x86_64 headers were
originally derived).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Ensure that all headers (PCI, UNDI, PnP, iPXE) are aligned to at least
four bytes, so that all accesses to header fields will be correctly
aligned even when reading directly from the expansion ROM BAR.
Reported-by: Peter von Konigsmark <peter@exablaze.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
We must not steal ownership from the Gen 2 UEFI firmware, since doing
so will cause an immediate system crash (most likely in the form of a
reboot).
This problem was masked before commit a0f6e75 ("[hyperv] Do not fail
if guest OS ID MSR is already set"), since prior to that commit we
would always fail if we found any non-zero guest OS identity. We now
accept a non-zero previous guest OS identity in order to allow for
situations such as chainloading from iPXE to another iPXE, and as a
prerequisite for commit b91cc98 ("[hyperv] Cope with Windows Server
2016 enlightenments").
A proper fix would be to reverse engineer the UEFI protocols exposed
within the Hyper-V Gen 2 firmware and use these to bind to the VMBus
device representing the network connection, (with the native Hyper-V
driver moved to become a BIOS-only feature).
As an interim solution, fail to initialise the native Hyper-V driver
if we detect the guest OS identity known to be used by the Gen 2 UEFI
firmware. This will cause the standard all-drivers build (ipxe.efi)
to fall back to using the SNP driver.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
EDK2 commit 6440385 ("MdePkg/Include: Add enumeration size checks to
Base.h") enforced the UEFI specification mandate that enums should
always be 32 bits. This revealed a latent bug in iPXE, which does not
build with -fno-short-enums.
Fix by adding -fno-short-enums to CFLAGS for ARM32 EFI builds.
Reported-by: Benjamin S. Allen <bsallen@alcf.anl.gov>
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>
For some CPUID leaves (e.g. %eax=0x00000004), the result depends on
the input value of %ecx. Allow this subfunction number to be
specified as a parameter to the cpuid() wrapper.
The subfunction number is exposed via the ${cpuid/...} settings
mechanism using the syntax
${cpuid/<subfunction>.0x40.<register>.<function>}
e.g.
${cpuid/0.0x40.0.0x0000000b}
${cpuid/1.0x40.0.0x0000000b}
to retrieve the CPU topology information.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some distributions patch gcc to generate position independent
executables by default. We currently include a workaround to check
for this and to add -fno-PIE -nopie to CFLAGS if required.
Newer patched versions of gcc require -fno-PIE -no-pie instead. Check
for both variants.
Reported-by: Nathan Rennie-Waldock <nathan.renniewaldock@gmail.com>
Originally-fixed-by: Markos Chandras <mchandras@suse.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When booting from a hard disk image (e.g. bin/ipxe.usb) within an
emulator such as QEMU, the disk may not exist beyond the end of the
image. Limit all reads to the length of the image to avoid spurious
errors when loading the iPXE image.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
An "enlightened" external bootloader (such as Windows Server 2016's
winload.exe) may take ownership of the Hyper-V connection before all
INT 13 operations have been completed. When this happens, all VMBus
devices are implicitly closed and we are left with a non-functional
network connection.
Detect when our Hyper-V connection has been lost (by checking the
SynIC message page MSR). Reclaim ownership of the Hyper-V connection
and reestablish any VMBus devices, without disrupting any existing
iPXE state (such as IPv4 settings attached to the network device).
Windows Server 2016 will not cleanly take ownership of an active
Hyper-V connection. Experimentation shows that we can quiesce by
resetting only the SynIC message page MSR; this results in a
successful SAN boot (on a Windows 2012 R2 physical host). Choose to
quiesce by resetting (almost) all MSRs, in the hope that this will be
more robust against corner cases such as a stray synthetic interrupt
occurring during the handover.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown
Dentcho Ludmilov Bankov
David Decotigny
Petr Borsodi