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Diffstat (limited to 'Documentation/riscv/boot-image-header.txt')
| -rw-r--r-- | Documentation/riscv/boot-image-header.txt | 50 |
1 files changed, 0 insertions, 50 deletions
diff --git a/Documentation/riscv/boot-image-header.txt b/Documentation/riscv/boot-image-header.txt deleted file mode 100644 index 1b73fea23b39..000000000000 --- a/Documentation/riscv/boot-image-header.txt +++ /dev/null @@ -1,50 +0,0 @@ - Boot image header in RISC-V Linux - ============================================= - -Author: Atish Patra <atish.patra@wdc.com> -Date : 20 May 2019 - -This document only describes the boot image header details for RISC-V Linux. -The complete booting guide will be available at Documentation/riscv/booting.txt. - -The following 64-byte header is present in decompressed Linux kernel image. - - u32 code0; /* Executable code */ - u32 code1; /* Executable code */ - u64 text_offset; /* Image load offset, little endian */ - u64 image_size; /* Effective Image size, little endian */ - u64 flags; /* kernel flags, little endian */ - u32 version; /* Version of this header */ - u32 res1 = 0; /* Reserved */ - u64 res2 = 0; /* Reserved */ - u64 magic = 0x5643534952; /* Magic number, little endian, "RISCV" */ - u32 res3; /* Reserved for additional RISC-V specific header */ - u32 res4; /* Reserved for PE COFF offset */ - -This header format is compliant with PE/COFF header and largely inspired from -ARM64 header. Thus, both ARM64 & RISC-V header can be combined into one common -header in future. - -Notes: -- This header can also be reused to support EFI stub for RISC-V in future. EFI - specification needs PE/COFF image header in the beginning of the kernel image - in order to load it as an EFI application. In order to support EFI stub, - code0 should be replaced with "MZ" magic string and res5(at offset 0x3c) should - point to the rest of the PE/COFF header. - -- version field indicate header version number. - Bits 0:15 - Minor version - Bits 16:31 - Major version - - This preserves compatibility across newer and older version of the header. - The current version is defined as 0.1. - -- res3 is reserved for offset to any other additional fields. This makes the - header extendible in future. One example would be to accommodate ISA - extension for RISC-V in future. For current version, it is set to be zero. - -- In current header, the flag field has only one field. - Bit 0: Kernel endianness. 1 if BE, 0 if LE. - -- Image size is mandatory for boot loader to load kernel image. Booting will - fail otherwise. |