This is a minimal respin of the RFC patch I sent out a few week ago. No
changes were applied except the /0x30/0x38 typo fix and some additional
wording in the commit log. I also added a patch to make the command line
initrd loader always built-in.
The purpose of all of this is to create *and document* a common baseline
for EFI booting of Linux. (I know I promised some documentation myself,
but I simply don't have time for that, so if anyone feels so inclined,
please go ahead).
The idea is that EFI images with the LINUX_PE_MAGIC number are
guaranteed to support:
- initrd loading via LoadFile2
- initrd loading via the command line
- (on x86) mixed mode boot via the .compat entry point
- other things I missed?
Architectures such as arm64 and RISC-V already have their own magic
numbers, in which case the PE/COFF major/minor image version should be
inspected, where 1.1 corresponds with the set described above.
If other architectures want to create hybrid images as well, it would be
better to use a different offset to store the magic number, so that the
generic EFI one can be carried as well. The reason for deviating from
this for arm64 and RISC-V is the simple fact that existing images
already exist, so for those architectures, we have to consider both
anyway.
Cc: Huacai Chen <chenhuacai@xxxxxxxxxx>
Cc: Atish Patra <atishp@xxxxxxxxxxxx>
Cc: Heinrich Schuchardt <heinrich.schuchardt@xxxxxxxxxxxxx>
Cc: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
Cc: Leif Lindholm <quic_llindhol@xxxxxxxxxxx>
Ard Biesheuvel (2):
efi: libstub: Always enable initrd command line loader and bump
version
efi: Put Linux specific magic number in the DOS header
arch/loongarch/kernel/head.S | 3 ++-
arch/x86/boot/header.S | 3 ++-
drivers/firmware/efi/Kconfig | 15 ---------------
drivers/firmware/efi/libstub/efi-stub-helper.c | 3 +--
drivers/firmware/efi/libstub/zboot-header.S | 3 ++-
include/linux/pe.h | 9 ++++++++-
6 files changed, 15 insertions(+), 21 deletions(-)
--
2.35.1
