diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2022-09-16 19:48:53 +0200 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2022-09-27 13:22:49 +0200 |
| commit | 40cd01a9c324bd238e107d9d5ecb6824146a7836 (patch) | |
| tree | b7b4c48c8da21e7429e6aaded84fd6ad563fbad3 /arch/loongarch/Kconfig | |
| parent | 171539f5a90e3fdf7d17f5396fac79d7e44ad68e (diff) | |
| download | linux-40cd01a9c324bd238e107d9d5ecb6824146a7836.tar.bz2 | |
efi/loongarch: libstub: remove dependency on flattened DT
LoongArch does not use FDT or DT natively [yet], and the only reason it
currently uses it is so that it can reuse the existing EFI stub code.
Overloading the DT with data passed between the EFI stub and the core
kernel has been a source of problems: there is the overlap between
information provided by EFI which DT can also provide (initrd base/size,
command line, memory descriptions), requiring us to reason about which
is which and what to prioritize. It has also resulted in ABI leaks,
i.e., internal ABI being promoted to external ABI inadvertently because
the bootloader can set the EFI stub's DT properties as well (e.g.,
"kaslr-seed"). This has become especially problematic with boot
environments that want to pretend that EFI boot is being done (to access
ACPI and SMBIOS tables, for instance) but have no ability to execute the
EFI stub, and so the environment that the EFI stub creates is emulated
[poorly, in some cases].
Another downside of treating DT like this is that the DT binary that the
kernel receives is different from the one created by the firmware, which
is undesirable in the context of secure and measured boot.
Given that LoongArch support in Linux is brand new, we can avoid these
pitfalls, and treat the DT strictly as a hardware description, and use a
separate handover method between the EFI stub and the kernel. Now that
initrd loading and passing the EFI memory map have been refactored into
pure EFI routines that use EFI configuration tables, the only thing we
need to pass directly is the kernel command line (even if we could pass
this via a config table as well, it is used extremely early, so passing
it directly is preferred in this case.)
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/Kconfig')
| -rw-r--r-- | arch/loongarch/Kconfig | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index fca106a8b8af..14a2a1ec8561 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -104,8 +104,6 @@ config LOONGARCH select MODULES_USE_ELF_RELA if MODULES select NEED_PER_CPU_EMBED_FIRST_CHUNK select NEED_PER_CPU_PAGE_FIRST_CHUNK - select OF - select OF_EARLY_FLATTREE select PCI select PCI_DOMAINS_GENERIC select PCI_ECAM if ACPI @@ -311,7 +309,6 @@ config DMI config EFI bool "EFI runtime service support" select UCS2_STRING - select EFI_PARAMS_FROM_FDT select EFI_RUNTIME_WRAPPERS help This enables the kernel to use EFI runtime services that are |