diff options
Diffstat (limited to 'Documentation/arm64/booting.txt')
| -rw-r--r-- | Documentation/arm64/booting.txt | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/Documentation/arm64/booting.txt b/Documentation/arm64/booting.txt index 9c4d388dadd..98df4a03807 100644 --- a/Documentation/arm64/booting.txt +++ b/Documentation/arm64/booting.txt @@ -45,9 +45,9 @@ sees fit.) Requirement: MANDATORY -The device tree blob (dtb) must be no bigger than 2 megabytes in size -and placed at a 2-megabyte boundary within the first 512 megabytes from -the start of the kernel image. This is to allow the kernel to map the +The device tree blob (dtb) must be placed on an 8-byte boundary within +the first 512 megabytes from the start of the kernel image and must not +cross a 2-megabyte boundary. This is to allow the kernel to map the blob using a single section mapping in the initial page tables. @@ -68,13 +68,23 @@ Image target is available instead. Requirement: MANDATORY -The decompressed kernel image contains a 32-byte header as follows: +The decompressed kernel image contains a 64-byte header as follows: - u32 magic = 0x14000008; /* branch to stext, little-endian */ - u32 res0 = 0; /* reserved */ + u32 code0; /* Executable code */ + u32 code1; /* Executable code */ u64 text_offset; /* Image load offset */ + u64 res0 = 0; /* reserved */ u64 res1 = 0; /* reserved */ u64 res2 = 0; /* reserved */ + u64 res3 = 0; /* reserved */ + u64 res4 = 0; /* reserved */ + u32 magic = 0x644d5241; /* Magic number, little endian, "ARM\x64" */ + u32 res5 = 0; /* reserved */ + + +Header notes: + +- code0/code1 are responsible for branching to stext. The image must be placed at the specified offset (currently 0x80000) from the start of the system RAM and called there. The start of the |