1 /* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
2  * Use of this source code is governed by a BSD-style license that can be
3  * found in the LICENSE file.
4  *
5  * Defines UEFI related structure. See more details in the UEFI spec.
6  *
7  * To download UEFI standard, please visit UEFI homepage:
8  *    http://www.uefi.org/
9  */
10 #ifndef VBOOT_REFERENCE_CGPTLIB_GPT_H_
11 #define VBOOT_REFERENCE_CGPTLIB_GPT_H_
12 #include <stdint.h>
13 
14 /* From the specification */
15 #define GPT_HEADER_SIGNATURE_SIZE 8
16 #define GPT_HEADER_REVISION 0x00010000
17 #define GPT_HEADER_SIGNATURE  "EFI PART"
18 
19 /* From https://chromium-review.googlesource.com/31264 */
20 #define GPT_HEADER_SIGNATURE2 "CHROMEOS"
21 
22 /*
23  * The first 3 numbers should be stored in network-endian format according to
24  * the GUID RFC.  The UEFI spec appendix A claims they should be stored in
25  * little-endian format.  But they need to be _displayed_ in network-endian
26  * format, which is also how they're documented in the specs.
27  *
28  * Since what we have here are little-endian constants, they're byte-swapped
29  * from the normal display order.
30  */
31 #define GPT_ENT_TYPE_UNUSED \
32 	{{{0x00000000,0x0000,0x0000,0x00,0x00,{0x00,0x00,0x00,0x00,0x00,0x00}}}}
33 #define GPT_ENT_TYPE_EFI \
34 	{{{0xc12a7328,0xf81f,0x11d2,0xba,0x4b,{0x00,0xa0,0xc9,0x3e,0xc9,0x3b}}}}
35 #define GPT_ENT_TYPE_CHROMEOS_FIRMWARE \
36 	{{{0xcab6e88e,0xabf3,0x4102,0xa0,0x7a,{0xd4,0xbb,0x9b,0xe3,0xc1,0xd3}}}}
37 #define GPT_ENT_TYPE_CHROMEOS_KERNEL \
38 	{{{0xfe3a2a5d,0x4f32,0x41a7,0xb7,0x25,{0xac,0xcc,0x32,0x85,0xa3,0x09}}}}
39 #define GPT_ENT_TYPE_CHROMEOS_ROOTFS \
40 	{{{0x3cb8e202,0x3b7e,0x47dd,0x8a,0x3c,{0x7f,0xf2,0xa1,0x3c,0xfc,0xec}}}}
41 #define GPT_ENT_TYPE_CHROMEOS_RESERVED \
42 	{{{0x2e0a753d,0x9e48,0x43b0,0x83,0x37,{0xb1,0x51,0x92,0xcb,0x1b,0x5e}}}}
43 #define GPT_ENT_TYPE_LINUX_DATA \
44 	{{{0xebd0a0a2,0xb9e5,0x4433,0x87,0xc0,{0x68,0xb6,0xb7,0x26,0x99,0xc7}}}}
45 #define GPT_ENT_TYPE_LINUX_FS \
46 	{{{0x0fc63daf,0x8483,0x4772,0x8e,0x79,{0x3d,0x69,0xd8,0x47,0x7d,0xe4}}}}
47 
48 #define UUID_NODE_LEN 6
49 #define GUID_SIZE 16
50 
51 /* GUID definition. Defined in appendix A of UEFI standard. */
52 typedef struct {
53 	union {
54 		struct {
55 			uint32_t time_low;
56 			uint16_t time_mid;
57 			uint16_t time_high_and_version;
58 			uint8_t clock_seq_high_and_reserved;
59 			uint8_t clock_seq_low;
60 			uint8_t node[UUID_NODE_LEN];
61 		} Uuid;
62 		uint8_t raw[GUID_SIZE];
63 	} u;
64 } __attribute__((packed)) Guid;
65 
66 #define GUID_EXPECTED_SIZE GUID_SIZE
67 
68 /*
69  * GPT header defines how many partitions exist on a drive and sectors managed.
70  * For every drive device, there are 2 headers, primary and secondary.  Most of
71  * the fields are duplicates except my_lba and entries_lba.
72  *
73  * You may find more details in chapter 5 of the UEFI standard.
74  */
75 typedef struct {
76 	char signature[GPT_HEADER_SIGNATURE_SIZE];
77 	uint32_t revision;
78 	uint32_t size;
79 	uint32_t header_crc32;
80 	uint32_t reserved_zero;
81 	uint64_t my_lba;
82 	uint64_t alternate_lba;
83 	uint64_t first_usable_lba;
84 	uint64_t last_usable_lba;
85 	Guid disk_uuid;
86 	uint64_t entries_lba;
87 	uint32_t number_of_entries;
88 	uint32_t size_of_entry;
89 	uint32_t entries_crc32;
90 	/* Remainder of sector is reserved and should be 0 */
91 } __attribute__((packed)) GptHeader;
92 
93 #define GPTHEADER_EXPECTED_SIZE 92
94 
95 /*
96  * GPT partition entry defines the starting and ending LBAs of a partition.  It
97  * also contains the unique GUID, type, and attribute bits.
98  *
99  * You may find more details in chapter 5 of the UEFI standard.
100  */
101 typedef struct {
102 	Guid type;
103 	Guid unique;
104 	uint64_t starting_lba;
105 	uint64_t ending_lba;
106 	union {
107 		struct {
108 			uint16_t reserved[3];
109 			uint16_t gpt_att;
110 		} __attribute__((packed)) fields;
111 		uint64_t whole;
112 	} attrs;
113 	uint16_t name[36];  /* UTF-16 encoded partition name */
114 	/* Remainder of entry is reserved and should be 0 */
115 } __attribute__((packed)) GptEntry;
116 
117 #define GPTENTRY_EXPECTED_SIZE 128
118 
119 #endif  /* VBOOT_REFERENCE_CGPTLIB_GPT_H_ */
120