Pull EFI updates from Ard Biesheuvel:
"A bit more going on than usual in the EFI subsystem. The main driver
for this has been the introduction of the LoonArch architecture last
cycle, which inspired some cleanup and refactoring of the EFI code.
Another driver for EFI changes this cycle and in the future is
confidential compute.
The LoongArch architecture does not use either struct bootparams or DT
natively [yet], and so passing information between the EFI stub and
the core kernel using either of those is undesirable. And in general,
overloading DT has been a source of issues on arm64, so using DT for
this on new architectures is a to avoid for the time being (even if we
might converge on something DT based for non-x86 architectures in the
future). For this reason, in addition to the patch that enables EFI
boot for LoongArch, there are a number of refactoring patches applied
on top of which separate the DT bits from the generic EFI stub bits.
These changes are on a separate topich branch that has been shared
with the LoongArch maintainers, who will include it in their pull
request as well. This is not ideal, but the best way to manage the
conflicts without stalling LoongArch for another cycle.
Another development inspired by LoongArch is the newly added support
for EFI based decompressors. Instead of adding yet another
arch-specific incarnation of this pattern for LoongArch, we are
introducing an EFI app based on the existing EFI libstub
infrastructure that encapulates the decompression code we use on other
architectures, but in a way that is fully generic. This has been
developed and tested in collaboration with distro and systemd folks,
who are eager to start using this for systemd-boot and also for arm64
secure boot on Fedora. Note that the EFI zimage files this introduces
can also be decompressed by non-EFI bootloaders if needed, as the
image header describes the location of the payload inside the image,
and the type of compression that was used. (Note that Fedora's arm64
GRUB is buggy [0] so you'll need a recent version or switch to
systemd-boot in order to use this.)
Finally, we are adding TPM measurement of the kernel command line
provided by EFI. There is an oversight in the TCG spec which results
in a blind spot for command line arguments passed to loaded images,
which means that either the loader or the stub needs to take the
measurement. Given the combinatorial explosion I am anticipating when
it comes to firmware/bootloader stacks and firmware based attestation
protocols (SEV-SNP, TDX, DICE, DRTM), it is good to set a baseline now
when it comes to EFI measured boot, which is that the kernel measures
the initrd and command line. Intermediate loaders can measure
additional assets if needed, but with the baseline in place, we can
deploy measured boot in a meaningful way even if you boot into Linux
straight from the EFI firmware.
Summary:
- implement EFI boot support for LoongArch
- implement generic EFI compressed boot support for arm64, RISC-V and
LoongArch, none of which implement a decompressor today
- measure the kernel command line into the TPM if measured boot is in
effect
- refactor the EFI stub code in order to isolate DT dependencies for
architectures other than x86
- avoid calling SetVirtualAddressMap() on arm64 if the configured
size of the VA space guarantees that doing so is unnecessary
- move some ARM specific code out of the generic EFI source files
- unmap kernel code from the x86 mixed mode 1:1 page tables"
* tag 'efi-next-for-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits)
efi/arm64: libstub: avoid SetVirtualAddressMap() when possible
efi: zboot: create MemoryMapped() device path for the parent if needed
efi: libstub: fix up the last remaining open coded boot service call
efi/arm: libstub: move ARM specific code out of generic routines
efi/libstub: measure EFI LoadOptions
efi/libstub: refactor the initrd measuring functions
efi/loongarch: libstub: remove dependency on flattened DT
efi: libstub: install boot-time memory map as config table
efi: libstub: remove DT dependency from generic stub
efi: libstub: unify initrd loading between architectures
efi: libstub: remove pointless goto kludge
efi: libstub: simplify efi_get_memory_map() and struct efi_boot_memmap
efi: libstub: avoid efi_get_memory_map() for allocating the virt map
efi: libstub: drop pointless get_memory_map() call
efi: libstub: fix type confusion for load_options_size
arm64: efi: enable generic EFI compressed boot
loongarch: efi: enable generic EFI compressed boot
riscv: efi: enable generic EFI compressed boot
efi/libstub: implement generic EFI zboot
efi/libstub: move efi_system_table global var into separate object
...
#include <asm/loongarch.h>
#include <asm/stackframe.h>
+ #ifdef CONFIG_EFI_STUB
+
+ #include "efi-header.S"
+
+ __HEAD
+
+ _head:
+ .word MZ_MAGIC /* "MZ", MS-DOS header */
+ .org 0x3c /* 0x04 ~ 0x3b reserved */
+ .long pe_header - _head /* Offset to the PE header */
+
+ pe_header:
+ __EFI_PE_HEADER
+
+ SYM_DATA(kernel_asize, .long _end - _text);
+ SYM_DATA(kernel_fsize, .long _edata - _text);
+ SYM_DATA(kernel_offset, .long kernel_offset - _text);
+
+ #endif
+
__REF
+ .align 12
+
SYM_CODE_START(kernel_entry) # kernel entry point
/* Config direct window and set PG */
projects / linux-2.6-microblaze.git / commitdiff