1 /*
2 * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include <assert.h>
8 #include <debug.h>
9 #include <gpt.h>
10 #include <io_storage.h>
11 #include <mbr.h>
12 #include <partition.h>
13 #include <platform.h>
14 #include <string.h>
15
16 static uint8_t mbr_sector[PARTITION_BLOCK_SIZE];
17 partition_entry_list_t list;
18
19 #if LOG_LEVEL >= LOG_LEVEL_VERBOSE
dump_entries(int num)20 static void dump_entries(int num)
21 {
22 char name[EFI_NAMELEN];
23 int i, j, len;
24
25 VERBOSE("Partition table with %d entries:\n", num);
26 for (i = 0; i < num; i++) {
27 len = snprintf(name, EFI_NAMELEN, "%s", list.list[i].name);
28 for (j = 0; j < EFI_NAMELEN - len - 1; j++) {
29 name[len + j] = ' ';
30 }
31 name[EFI_NAMELEN - 1] = '\0';
32 VERBOSE("%d: %s %lx-%lx\n", i + 1, name, list.list[i].start,
33 list.list[i].start + list.list[i].length - 4);
34 }
35 }
36 #else
37 #define dump_entries(num) ((void)num)
38 #endif
39
40 /*
41 * Load the first sector that carries MBR header.
42 * The MBR boot signature should be always valid whether it's MBR or GPT.
43 */
load_mbr_header(uintptr_t image_handle,mbr_entry_t * mbr_entry)44 static int load_mbr_header(uintptr_t image_handle, mbr_entry_t *mbr_entry)
45 {
46 size_t bytes_read;
47 uintptr_t offset;
48 int result;
49
50 assert(mbr_entry != NULL);
51 /* MBR partition table is in LBA0. */
52 result = io_seek(image_handle, IO_SEEK_SET, MBR_OFFSET);
53 if (result != 0) {
54 WARN("Failed to seek (%i)\n", result);
55 return result;
56 }
57 result = io_read(image_handle, (uintptr_t)&mbr_sector,
58 PARTITION_BLOCK_SIZE, &bytes_read);
59 if (result != 0) {
60 WARN("Failed to read data (%i)\n", result);
61 return result;
62 }
63
64 /* Check MBR boot signature. */
65 if ((mbr_sector[PARTITION_BLOCK_SIZE - 2] != MBR_SIGNATURE_FIRST) ||
66 (mbr_sector[PARTITION_BLOCK_SIZE - 1] != MBR_SIGNATURE_SECOND)) {
67 return -ENOENT;
68 }
69 offset = (uintptr_t)&mbr_sector + MBR_PRIMARY_ENTRY_OFFSET;
70 memcpy(mbr_entry, (void *)offset, sizeof(mbr_entry_t));
71 return 0;
72 }
73
74 /*
75 * Load GPT header and check the GPT signature.
76 * If partiton numbers could be found, check & update it.
77 */
load_gpt_header(uintptr_t image_handle)78 static int load_gpt_header(uintptr_t image_handle)
79 {
80 gpt_header_t header;
81 size_t bytes_read;
82 int result;
83
84 result = io_seek(image_handle, IO_SEEK_SET, GPT_HEADER_OFFSET);
85 if (result != 0) {
86 return result;
87 }
88 result = io_read(image_handle, (uintptr_t)&header,
89 sizeof(gpt_header_t), &bytes_read);
90 if ((result != 0) || (sizeof(gpt_header_t) != bytes_read)) {
91 return result;
92 }
93 if (memcmp(header.signature, GPT_SIGNATURE,
94 sizeof(header.signature)) != 0) {
95 return -EINVAL;
96 }
97
98 /* partition numbers can't exceed PLAT_PARTITION_MAX_ENTRIES */
99 list.entry_count = header.list_num;
100 if (list.entry_count > PLAT_PARTITION_MAX_ENTRIES) {
101 list.entry_count = PLAT_PARTITION_MAX_ENTRIES;
102 }
103 return 0;
104 }
105
load_gpt_entry(uintptr_t image_handle,gpt_entry_t * entry)106 static int load_gpt_entry(uintptr_t image_handle, gpt_entry_t *entry)
107 {
108 size_t bytes_read;
109 int result;
110
111 assert(entry != NULL);
112 result = io_read(image_handle, (uintptr_t)entry, sizeof(gpt_entry_t),
113 &bytes_read);
114 if (sizeof(gpt_entry_t) != bytes_read)
115 return -EINVAL;
116 return result;
117 }
118
verify_partition_gpt(uintptr_t image_handle)119 static int verify_partition_gpt(uintptr_t image_handle)
120 {
121 gpt_entry_t entry;
122 int result, i;
123
124 for (i = 0; i < list.entry_count; i++) {
125 result = load_gpt_entry(image_handle, &entry);
126 assert(result == 0);
127 result = parse_gpt_entry(&entry, &list.list[i]);
128 if (result != 0) {
129 break;
130 }
131 }
132 if (i == 0) {
133 return -EINVAL;
134 }
135 /*
136 * Only records the valid partition number that is loaded from
137 * partition table.
138 */
139 list.entry_count = i;
140 dump_entries(list.entry_count);
141
142 return 0;
143 }
144
load_partition_table(unsigned int image_id)145 int load_partition_table(unsigned int image_id)
146 {
147 uintptr_t dev_handle, image_handle, image_spec = 0;
148 mbr_entry_t mbr_entry;
149 int result;
150
151 result = plat_get_image_source(image_id, &dev_handle, &image_spec);
152 if (result != 0) {
153 WARN("Failed to obtain reference to image id=%u (%i)\n",
154 image_id, result);
155 return result;
156 }
157
158 result = io_open(dev_handle, image_spec, &image_handle);
159 if (result != 0) {
160 WARN("Failed to access image id=%u (%i)\n", image_id, result);
161 return result;
162 }
163
164 result = load_mbr_header(image_handle, &mbr_entry);
165 if (result != 0) {
166 WARN("Failed to access image id=%u (%i)\n", image_id, result);
167 return result;
168 }
169 if (mbr_entry.type == PARTITION_TYPE_GPT) {
170 result = load_gpt_header(image_handle);
171 assert(result == 0);
172 result = io_seek(image_handle, IO_SEEK_SET, GPT_ENTRY_OFFSET);
173 assert(result == 0);
174 result = verify_partition_gpt(image_handle);
175 } else {
176 /* MBR type isn't supported yet. */
177 result = -EINVAL;
178 goto exit;
179 }
180 exit:
181 io_close(image_handle);
182 return result;
183 }
184
get_partition_entry(const char * name)185 const partition_entry_t *get_partition_entry(const char *name)
186 {
187 int i;
188
189 for (i = 0; i < list.entry_count; i++) {
190 if (strcmp(name, list.list[i].name) == 0) {
191 return &list.list[i];
192 }
193 }
194 return NULL;
195 }
196
get_partition_entry_list(void)197 const partition_entry_list_t *get_partition_entry_list(void)
198 {
199 return &list;
200 }
201
partition_init(unsigned int image_id)202 void partition_init(unsigned int image_id)
203 {
204 load_partition_table(image_id);
205 }
206