1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <errno.h>
18 #include <fcntl.h>
19 #include <inttypes.h>
20 #include <stdio.h>
21 #include <string.h>
22 #include <sys/stat.h>
23 #include <sys/types.h>
24 #include <unistd.h>
25
26 #include <fs_mgr.h>
27
28 #include "bootloader.h"
29 #include "common.h"
30 #include "mtdutils/mtdutils.h"
31 #include "roots.h"
32 #include "unique_fd.h"
33
34 static int get_bootloader_message_mtd(bootloader_message* out, const Volume* v);
35 static int set_bootloader_message_mtd(const bootloader_message* in, const Volume* v);
36 static int get_bootloader_message_block(bootloader_message* out, const Volume* v);
37 static int set_bootloader_message_block(const bootloader_message* in, const Volume* v);
38
get_bootloader_message(bootloader_message * out)39 int get_bootloader_message(bootloader_message* out) {
40 Volume* v = volume_for_path("/misc");
41 if (v == nullptr) {
42 LOGE("Cannot load volume /misc!\n");
43 return -1;
44 }
45 if (strcmp(v->fs_type, "mtd") == 0) {
46 return get_bootloader_message_mtd(out, v);
47 } else if (strcmp(v->fs_type, "emmc") == 0) {
48 return get_bootloader_message_block(out, v);
49 }
50 LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
51 return -1;
52 }
53
set_bootloader_message(const bootloader_message * in)54 int set_bootloader_message(const bootloader_message* in) {
55 Volume* v = volume_for_path("/misc");
56 if (v == nullptr) {
57 LOGE("Cannot load volume /misc!\n");
58 return -1;
59 }
60 if (strcmp(v->fs_type, "mtd") == 0) {
61 return set_bootloader_message_mtd(in, v);
62 } else if (strcmp(v->fs_type, "emmc") == 0) {
63 return set_bootloader_message_block(in, v);
64 }
65 LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
66 return -1;
67 }
68
69 // ------------------------------
70 // for misc partitions on MTD
71 // ------------------------------
72
73 static const int MISC_PAGES = 3; // number of pages to save
74 static const int MISC_COMMAND_PAGE = 1; // bootloader command is this page
75
get_bootloader_message_mtd(bootloader_message * out,const Volume * v)76 static int get_bootloader_message_mtd(bootloader_message* out,
77 const Volume* v) {
78 size_t write_size;
79 mtd_scan_partitions();
80 const MtdPartition* part = mtd_find_partition_by_name(v->blk_device);
81 if (part == nullptr || mtd_partition_info(part, nullptr, nullptr, &write_size)) {
82 LOGE("failed to find \"%s\"\n", v->blk_device);
83 return -1;
84 }
85
86 MtdReadContext* read = mtd_read_partition(part);
87 if (read == nullptr) {
88 LOGE("failed to open \"%s\": %s\n", v->blk_device, strerror(errno));
89 return -1;
90 }
91
92 const ssize_t size = write_size * MISC_PAGES;
93 char data[size];
94 ssize_t r = mtd_read_data(read, data, size);
95 if (r != size) LOGE("failed to read \"%s\": %s\n", v->blk_device, strerror(errno));
96 mtd_read_close(read);
97 if (r != size) return -1;
98
99 memcpy(out, &data[write_size * MISC_COMMAND_PAGE], sizeof(*out));
100 return 0;
101 }
set_bootloader_message_mtd(const bootloader_message * in,const Volume * v)102 static int set_bootloader_message_mtd(const bootloader_message* in,
103 const Volume* v) {
104 size_t write_size;
105 mtd_scan_partitions();
106 const MtdPartition* part = mtd_find_partition_by_name(v->blk_device);
107 if (part == nullptr || mtd_partition_info(part, nullptr, nullptr, &write_size)) {
108 LOGE("failed to find \"%s\"\n", v->blk_device);
109 return -1;
110 }
111
112 MtdReadContext* read = mtd_read_partition(part);
113 if (read == nullptr) {
114 LOGE("failed to open \"%s\": %s\n", v->blk_device, strerror(errno));
115 return -1;
116 }
117
118 ssize_t size = write_size * MISC_PAGES;
119 char data[size];
120 ssize_t r = mtd_read_data(read, data, size);
121 if (r != size) LOGE("failed to read \"%s\": %s\n", v->blk_device, strerror(errno));
122 mtd_read_close(read);
123 if (r != size) return -1;
124
125 memcpy(&data[write_size * MISC_COMMAND_PAGE], in, sizeof(*in));
126
127 MtdWriteContext* write = mtd_write_partition(part);
128 if (write == nullptr) {
129 LOGE("failed to open \"%s\": %s\n", v->blk_device, strerror(errno));
130 return -1;
131 }
132 if (mtd_write_data(write, data, size) != size) {
133 LOGE("failed to write \"%s\": %s\n", v->blk_device, strerror(errno));
134 mtd_write_close(write);
135 return -1;
136 }
137 if (mtd_write_close(write)) {
138 LOGE("failed to finish \"%s\": %s\n", v->blk_device, strerror(errno));
139 return -1;
140 }
141
142 LOGI("Set boot command \"%s\"\n", in->command[0] != 255 ? in->command : "");
143 return 0;
144 }
145
146
147 // ------------------------------------
148 // for misc partitions on block devices
149 // ------------------------------------
150
wait_for_device(const char * fn)151 static void wait_for_device(const char* fn) {
152 int tries = 0;
153 int ret;
154 do {
155 ++tries;
156 struct stat buf;
157 ret = stat(fn, &buf);
158 if (ret == -1) {
159 printf("failed to stat \"%s\" try %d: %s\n", fn, tries, strerror(errno));
160 sleep(1);
161 }
162 } while (ret && tries < 10);
163
164 if (ret) {
165 printf("failed to stat \"%s\"\n", fn);
166 }
167 }
168
get_bootloader_message_block(bootloader_message * out,const Volume * v)169 static int get_bootloader_message_block(bootloader_message* out,
170 const Volume* v) {
171 wait_for_device(v->blk_device);
172 FILE* f = fopen(v->blk_device, "rb");
173 if (f == nullptr) {
174 LOGE("failed to open \"%s\": %s\n", v->blk_device, strerror(errno));
175 return -1;
176 }
177 bootloader_message temp;
178 int count = fread(&temp, sizeof(temp), 1, f);
179 if (count != 1) {
180 LOGE("failed to read \"%s\": %s\n", v->blk_device, strerror(errno));
181 return -1;
182 }
183 if (fclose(f) != 0) {
184 LOGE("failed to close \"%s\": %s\n", v->blk_device, strerror(errno));
185 return -1;
186 }
187 memcpy(out, &temp, sizeof(temp));
188 return 0;
189 }
190
set_bootloader_message_block(const bootloader_message * in,const Volume * v)191 static int set_bootloader_message_block(const bootloader_message* in,
192 const Volume* v) {
193 wait_for_device(v->blk_device);
194 unique_fd fd(open(v->blk_device, O_WRONLY | O_SYNC));
195 if (fd.get() == -1) {
196 LOGE("failed to open \"%s\": %s\n", v->blk_device, strerror(errno));
197 return -1;
198 }
199
200 size_t written = 0;
201 const uint8_t* start = reinterpret_cast<const uint8_t*>(in);
202 size_t total = sizeof(*in);
203 while (written < total) {
204 ssize_t wrote = TEMP_FAILURE_RETRY(write(fd.get(), start + written, total - written));
205 if (wrote == -1) {
206 LOGE("failed to write %" PRId64 " bytes: %s\n",
207 static_cast<off64_t>(written), strerror(errno));
208 return -1;
209 }
210 written += wrote;
211 }
212
213 if (fsync(fd.get()) == -1) {
214 LOGE("failed to fsync \"%s\": %s\n", v->blk_device, strerror(errno));
215 return -1;
216 }
217 return 0;
218 }
219