diff --git a/Documentation/riscv/boot-image-header.txt b/Documentation/riscv/boot-image-header.txt index 1b73fea23b39..14b1492f689b 100644 --- a/Documentation/riscv/boot-image-header.txt +++ b/Documentation/riscv/boot-image-header.txt @@ -18,7 +18,7 @@ The following 64-byte header is present in decompressed Linux kernel image. 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 magic2 = 0x56534905; /* Magic number 2, little endian, "RSC\x05" */ u32 res4; /* Reserved for PE COFF offset */ This header format is compliant with PE/COFF header and largely inspired from @@ -37,13 +37,14 @@ Notes: Bits 16:31 - Major version This preserves compatibility across newer and older version of the header. - The current version is defined as 0.1. + The current version is defined as 0.2. -- 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. +- The "magic" field is deprecated as of version 0.2. In a future + release, it may be removed. This originally should have matched up + with the ARM64 header "magic" field, but unfortunately does not. + The "magic2" field replaces it, matching up with the ARM64 header. -- In current header, the flag field has only one field. +- In current header, the flags 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 diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h index ef28e106f247..344db5244547 100644 --- a/arch/riscv/include/asm/image.h +++ b/arch/riscv/include/asm/image.h @@ -3,7 +3,8 @@ #ifndef __ASM_IMAGE_H #define __ASM_IMAGE_H -#define RISCV_IMAGE_MAGIC "RISCV" +#define RISCV_IMAGE_MAGIC "RISCV\0\0\0" +#define RISCV_IMAGE_MAGIC2 "RSC\x05" #define RISCV_IMAGE_FLAG_BE_SHIFT 0 #define RISCV_IMAGE_FLAG_BE_MASK 0x1 @@ -23,7 +24,7 @@ #define __HEAD_FLAGS (__HEAD_FLAG(BE)) #define RISCV_HEADER_VERSION_MAJOR 0 -#define RISCV_HEADER_VERSION_MINOR 1 +#define RISCV_HEADER_VERSION_MINOR 2 #define RISCV_HEADER_VERSION (RISCV_HEADER_VERSION_MAJOR << 16 | \ RISCV_HEADER_VERSION_MINOR) @@ -39,9 +40,8 @@ * @version: version * @res1: reserved * @res2: reserved - * @magic: Magic number - * @res3: reserved (will be used for additional RISC-V specific - * header) + * @magic: Magic number (RISC-V specific; deprecated) + * @magic2: Magic number 2 (to match the ARM64 'magic' field pos) * @res4: reserved (will be used for PE COFF offset) * * The intention is for this header format to be shared between multiple @@ -58,7 +58,7 @@ struct riscv_image_header { u32 res1; u64 res2; u64 magic; - u32 res3; + u32 magic2; u32 res4; }; #endif /* __ASSEMBLY__ */ diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 0f1ba17e476f..52eec0c1bf30 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -39,9 +39,9 @@ ENTRY(_start) .word RISCV_HEADER_VERSION .word 0 .dword 0 - .asciz RISCV_IMAGE_MAGIC - .word 0 + .ascii RISCV_IMAGE_MAGIC .balign 4 + .ascii RISCV_IMAGE_MAGIC2 .word 0 .global _start_kernel