From: Ahmad Fatoum <[email protected]> Linux kernels built with CONFIG_EFI_ZBOOT are EFI applications that decompress the actual kernel and hand it to the EFI stub. They carry "zimg" at offset 4 and LINUX_PE_MAGIC at offset 0x38, but none of the architecture-specific magics barebox looks for, so they have been detected as plain MS-DOS executables so far.
bootm thus started them like any other EFI application: The Linux bootargs weren't passed as load options and, as EFI payload, barebox provided neither initrd nor device tree and didn't shut itself down. Let's add a filetype for them, count it as Linux EFI image and register image handlers and a binfmt hook, so they are booted the same way as the EFI-stubbed kernels barebox already knows. Tested with an arm64 Linux v7.2 zboot kernel and initrd on barebox as EFI loader and as EFI payload running on top of it. Assisted-by: Claude:opus-5.5 Signed-off-by: Ahmad Fatoum <[email protected]> --- common/filetype.c | 5 ++++- efi/loader/bootm.c | 7 +++++++ efi/payload/bootm.c | 7 +++++++ efi/payload/image.c | 6 ++++++ include/filetype.h | 8 ++++++++ 5 files changed, 32 insertions(+), 1 deletion(-) diff --git a/common/filetype.c b/common/filetype.c index a25be6e2fc7e..439f0529be69 100644 --- a/common/filetype.c +++ b/common/filetype.c @@ -92,6 +92,7 @@ static const struct filetype_str filetype_str[] = { [filetype_x86_linux_image] = { "x86 Linux image", "x86-linux" }, [filetype_x86_efi_linux_image] = { "x86 Linux/EFI image", "x86-efi-linux" }, [filetype_pxa_ntim] = { "Marvell PXA3xx NTIM image", "pxa-ntim" }, + [filetype_zboot_efi_linux_image] = { "Linux/EFI zboot image", "zboot-efi-linux" }, }; static const char *file_type_to_nr_string(enum filetype f) @@ -460,7 +461,8 @@ enum filetype file_detect_type(const void *_buf, size_t bufsize) return is_dos_exe(buf8) ? filetype_arm_efi_zimage : filetype_arm_zimage; if (is_dos_exe(buf8)) - return filetype_exe; + return is_zboot_efi_linux_image(buf) ? + filetype_zboot_efi_linux_image : filetype_exe; if (bufsize < 256) return filetype_unknown; @@ -605,6 +607,7 @@ bool filetype_is_linux_efi_image(enum filetype ft) case filetype_arm64_efi_linux_image: case filetype_riscv_efi_linux_image: case filetype_x86_efi_linux_image: + case filetype_zboot_efi_linux_image: return true; default: return false; diff --git a/efi/loader/bootm.c b/efi/loader/bootm.c index a68db742e173..4129441a47de 100644 --- a/efi/loader/bootm.c +++ b/efi/loader/bootm.c @@ -353,6 +353,12 @@ static struct image_handler arm32_linux_efi_handler = { .filetype = filetype_arm_efi_zimage, }; +static struct image_handler zboot_linux_efi_handler = { + .name = "Linux/EFI zboot image", + .bootm = efi_loader_bootm, + .filetype = filetype_zboot_efi_linux_image, +}; + static struct image_handler efi_image_loader = { .name = "EFI Application", .bootm = efi_loader_bootm, @@ -367,6 +373,7 @@ static int efiloader_bootm_register(void) register_image_handler(&aarch64_linux_efi_handler); if (IS_ENABLED(CONFIG_RISCV)) register_image_handler(&riscv_linux_efi_handler); + register_image_handler(&zboot_linux_efi_handler); return register_image_handler(&efi_image_loader); } late_initcall(efiloader_bootm_register); diff --git a/efi/payload/bootm.c b/efi/payload/bootm.c index 2f9cc3cbf76b..d074709e3975 100644 --- a/efi/payload/bootm.c +++ b/efi/payload/bootm.c @@ -258,12 +258,19 @@ static struct image_handler efi_arm64_handle_tr = { .filetype = filetype_arm64_efi_linux_image, }; +static struct image_handler efi_zboot_handle_tr = { + .name = "EFI zboot Linux kernel", + .bootm = do_bootm_efi_stub, + .filetype = filetype_zboot_efi_linux_image, +}; + BAREBOX_MAGICVAR(global.linux.efi.handover, "Use legacy x86 handover protocol instead of StartImage BootService"); static int efi_register_bootm_handler(void) { register_image_handler(&efi_app_handle_tr); + register_image_handler(&efi_zboot_handle_tr); if (IS_ENABLED(CONFIG_X86)) { if (IS_ENABLED(CONFIG_EFI_HANDOVER_PROTOCOL)) diff --git a/efi/payload/image.c b/efi/payload/image.c index c5a04d7967a9..76aca1c43cec 100644 --- a/efi/payload/image.c +++ b/efi/payload/image.c @@ -200,9 +200,15 @@ static struct binfmt_hook binfmt_x86_efi_hook = { .hook = efi_execute, }; +static struct binfmt_hook binfmt_zboot_efi_hook = { + .type = filetype_zboot_efi_linux_image, + .hook = efi_execute, +}; + static int efi_register_image_handler(void) { binfmt_register(&binfmt_efi_hook); + binfmt_register(&binfmt_zboot_efi_hook); if (IS_ENABLED(CONFIG_X86)) { register_image_handler(&non_efi_handle_linux_x86); diff --git a/include/filetype.h b/include/filetype.h index 91dc37b71c13..281f467abcb2 100644 --- a/include/filetype.h +++ b/include/filetype.h @@ -73,6 +73,7 @@ enum filetype { filetype_x86_linux_image, filetype_x86_efi_linux_image, filetype_pxa_ntim, + filetype_zboot_efi_linux_image, filetype_max, }; @@ -182,6 +183,13 @@ static inline bool is_barebox_riscv_head(const void *header) !memcmp(header + 48, "barebox", 8); } +/* "zimg" image type and LINUX_PE_MAGIC, see Linux zboot-header.S */ +static inline bool is_zboot_efi_linux_image(const void *header) +{ + return !memcmp(header + 4, "zimg", 4) && + le32_to_cpup(header + 56) == 0x818223cd; +} + static inline bool is_x86_linux_bootimage(const void *header) { return get_unaligned_le32(header + 0x202) == 0x53726448; -- 2.47.3
