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-rw-r--r--Documentation/riscv/boot-image-header.txt13
1 files changed, 7 insertions, 6 deletions
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