From d683bed5c76c54e6bc5c26eef2f8d7136a3c75c4 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 11 Aug 2022 16:51:57 +0200 Subject: [PATCH] loader/arm64/efi/linux: Remove magic number header field check The "ARM\x64" magic number in the file header identifies an image as one that implements the bare metal boot protocol, allowing the loader to simply move the file to a suitably aligned address in memory, with sufficient headroom for the trailing .bss segment (the required memory size is described in the header as well). Note of this matters for GRUB, as it only supports EFI boot. EFI does not care about this magic number, and nor should GRUB: this prevents us from booting other PE linux images, such as the generic EFI zboot decompressor, which is a pure PE/COFF image, and does not implement the bare metal boot protocol. So drop the magic number check. Signed-off-by: Ard Biesheuvel Reviewed-by: Daniel Kiper --- grub-core/loader/arm64/efi/linux.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/grub-core/loader/arm64/efi/linux.c b/grub-core/loader/arm64/efi/linux.c index 33df0e1fd..a9f5e05e4 100644 --- a/grub-core/loader/arm64/efi/linux.c +++ b/grub-core/loader/arm64/efi/linux.c @@ -57,9 +57,6 @@ static grub_addr_t initrd_end; static grub_err_t grub_arch_efi_linux_check_image (struct linux_arch_kernel_header * lh) { - if (lh->magic != GRUB_LINUX_ARMXX_MAGIC_SIGNATURE) - return grub_error(GRUB_ERR_BAD_OS, "invalid magic number"); - if ((lh->code0 & 0xffff) != GRUB_PE32_MAGIC) return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, N_("plain image kernel not supported - rebuild with CONFIG_(U)EFI_STUB enabled")); -- 2.43.0