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| author | Ard Biesheuvel <ardb@kernel.org> | 2020-11-17 13:47:29 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-11-17 16:14:20 +0000 |
| commit | 7919385b9fb3cefe495310e5c44ca8a6d9c446e8 (patch) | |
| tree | 875d2aa41d96a4b68c68ed2b404791e636577c19 /arch/arm64/kernel/head.S | |
| parent | b50a3225cdffef43b76b294fa7fb3cd1f32f50d0 (diff) | |
| download | linux-7919385b9fb3cefe495310e5c44ca8a6d9c446e8.tar.bz2 | |
arm64: head: tidy up the Image header definition
Even though support for EFI boot remains entirely optional for arm64,
it is unlikely that we will ever be able to repurpose the image header
fields that the EFI loader relies on, i.e., the magic NOP at offset
0x0 and the PE header address at offset 0x3c.
So let's factor out the differences into a 'efi_signature_nop' macro and
a local symbol representing the PE header address, and move the
conditional definitions into efi-header.S, taking into account whether
CONFIG_EFI is enabled or not. While at it, switch to a signature NOP
that behaves more like a NOP, i.e., one that only clobbers the
flags.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201117124729.12642-4-ardb@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/head.S')
| -rw-r--r-- | arch/arm64/kernel/head.S | 19 |
1 files changed, 2 insertions, 17 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index d8d9caf02834..c1f8f2c5be47 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -58,21 +58,11 @@ * in the entry routines. */ __HEAD -_head: /* * DO NOT MODIFY. Image header expected by Linux boot-loaders. */ -#ifdef CONFIG_EFI - /* - * This add instruction has no meaningful effect except that - * its opcode forms the magic "MZ" signature required by UEFI. - */ - add x13, x18, #0x16 - b primary_entry -#else + efi_signature_nop // special NOP to identity as PE/COFF executable b primary_entry // branch to kernel start, magic - .long 0 // reserved -#endif .quad 0 // Image load offset from start of RAM, little-endian le64sym _kernel_size_le // Effective size of kernel image, little-endian le64sym _kernel_flags_le // Informative flags, little-endian @@ -80,14 +70,9 @@ _head: .quad 0 // reserved .quad 0 // reserved .ascii ARM64_IMAGE_MAGIC // Magic number -#ifdef CONFIG_EFI - .long pe_header - _head // Offset to the PE header. + .long .Lpe_header_offset // Offset to the PE header. -pe_header: __EFI_PE_HEADER -#else - .long 0 // reserved -#endif __INIT |