1 /* tools/mkbootimg/bootimg.h
2 **
3 ** Copyright 2007, The Android Open Source Project
4 **
5 ** Licensed under the Apache License, Version 2.0 (the "License");
6 ** you may not use this file except in compliance with the License.
7 ** You may obtain a copy of the License at
8 **
9 **     http://www.apache.org/licenses/LICENSE-2.0
10 **
11 ** Unless required by applicable law or agreed to in writing, software
12 ** distributed under the License is distributed on an "AS IS" BASIS,
13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 ** See the License for the specific language governing permissions and
15 ** limitations under the License.
16 */
17 
18 #include <stdint.h>
19 
20 #ifndef _BOOT_IMAGE_H_
21 #define _BOOT_IMAGE_H_
22 
23 typedef struct boot_img_hdr boot_img_hdr;
24 
25 #define BOOT_MAGIC "ANDROID!"
26 #define BOOT_MAGIC_SIZE 8
27 #define BOOT_NAME_SIZE 16
28 #define BOOT_ARGS_SIZE 512
29 #define BOOT_EXTRA_ARGS_SIZE 1024
30 
31 struct boot_img_hdr
32 {
33     uint8_t magic[BOOT_MAGIC_SIZE];
34 
35     uint32_t kernel_size;  /* size in bytes */
36     uint32_t kernel_addr;  /* physical load addr */
37 
38     uint32_t ramdisk_size; /* size in bytes */
39     uint32_t ramdisk_addr; /* physical load addr */
40 
41     uint32_t second_size;  /* size in bytes */
42     uint32_t second_addr;  /* physical load addr */
43 
44     uint32_t tags_addr;    /* physical addr for kernel tags */
45     uint32_t page_size;    /* flash page size we assume */
46     uint32_t unused;       /* reserved for future expansion: MUST be 0 */
47 
48     /* operating system version and security patch level; for
49      * version "A.B.C" and patch level "Y-M-D":
50      * ver = A << 14 | B << 7 | C         (7 bits for each of A, B, C)
51      * lvl = ((Y - 2000) & 127) << 4 | M  (7 bits for Y, 4 bits for M)
52      * os_version = ver << 11 | lvl */
53     uint32_t os_version;
54 
55     uint8_t name[BOOT_NAME_SIZE]; /* asciiz product name */
56 
57     uint8_t cmdline[BOOT_ARGS_SIZE];
58 
59     uint32_t id[8]; /* timestamp / checksum / sha1 / etc */
60 
61     /* Supplemental command line data; kept here to maintain
62      * binary compatibility with older versions of mkbootimg */
63     uint8_t extra_cmdline[BOOT_EXTRA_ARGS_SIZE];
64 } __attribute__((packed));
65 
66 /*
67 ** +-----------------+
68 ** | boot header     | 1 page
69 ** +-----------------+
70 ** | kernel          | n pages
71 ** +-----------------+
72 ** | ramdisk         | m pages
73 ** +-----------------+
74 ** | second stage    | o pages
75 ** +-----------------+
76 **
77 ** n = (kernel_size + page_size - 1) / page_size
78 ** m = (ramdisk_size + page_size - 1) / page_size
79 ** o = (second_size + page_size - 1) / page_size
80 **
81 ** 0. all entities are page_size aligned in flash
82 ** 1. kernel and ramdisk are required (size != 0)
83 ** 2. second is optional (second_size == 0 -> no second)
84 ** 3. load each element (kernel, ramdisk, second) at
85 **    the specified physical address (kernel_addr, etc)
86 ** 4. prepare tags at tag_addr.  kernel_args[] is
87 **    appended to the kernel commandline in the tags.
88 ** 5. r0 = 0, r1 = MACHINE_TYPE, r2 = tags_addr
89 ** 6. if second_size != 0: jump to second_addr
90 **    else: jump to kernel_addr
91 */
92 
93 #if 0
94 typedef struct ptentry ptentry;
95 
96 struct ptentry {
97     char name[16];      /* asciiz partition name    */
98     unsigned start;     /* starting block number    */
99     unsigned length;    /* length in blocks         */
100     unsigned flags;     /* set to zero              */
101 };
102 
103 /* MSM Partition Table ATAG
104 **
105 ** length: 2 + 7 * n
106 ** atag:   0x4d534d70
107 **         <ptentry> x n
108 */
109 #endif
110 
111 #endif
112