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 "bootloader.h"
18 #include "common.h"
19 #include "mtdutils/mtdutils.h"
20 #include "roots.h"
21
22 #include <errno.h>
23 #include <stdio.h>
24 #include <string.h>
25 #include <sys/stat.h>
26 #include <unistd.h>
27
28 static int get_bootloader_message_mtd(struct bootloader_message *out, const Volume* v);
29 static int set_bootloader_message_mtd(const struct bootloader_message *in, const Volume* v);
30 static int get_bootloader_message_block(struct bootloader_message *out, const Volume* v);
31 static int set_bootloader_message_block(const struct bootloader_message *in, const Volume* v);
32
get_bootloader_message(struct bootloader_message * out)33 int get_bootloader_message(struct bootloader_message *out) {
34 Volume* v = volume_for_path("/misc");
35 if (v == NULL) {
36 LOGE("Cannot load volume /misc!\n");
37 return -1;
38 }
39 if (strcmp(v->fs_type, "mtd") == 0) {
40 return get_bootloader_message_mtd(out, v);
41 } else if (strcmp(v->fs_type, "emmc") == 0) {
42 return get_bootloader_message_block(out, v);
43 }
44 LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
45 return -1;
46 }
47
set_bootloader_message(const struct bootloader_message * in)48 int set_bootloader_message(const struct bootloader_message *in) {
49 Volume* v = volume_for_path("/misc");
50 if (v == NULL) {
51 LOGE("Cannot load volume /misc!\n");
52 return -1;
53 }
54 if (strcmp(v->fs_type, "mtd") == 0) {
55 return set_bootloader_message_mtd(in, v);
56 } else if (strcmp(v->fs_type, "emmc") == 0) {
57 return set_bootloader_message_block(in, v);
58 }
59 LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
60 return -1;
61 }
62
63 // ------------------------------
64 // for misc partitions on MTD
65 // ------------------------------
66
67 static const int MISC_PAGES = 3; // number of pages to save
68 static const int MISC_COMMAND_PAGE = 1; // bootloader command is this page
69
get_bootloader_message_mtd(struct bootloader_message * out,const Volume * v)70 static int get_bootloader_message_mtd(struct bootloader_message *out,
71 const Volume* v) {
72 size_t write_size;
73 mtd_scan_partitions();
74 const MtdPartition *part = mtd_find_partition_by_name(v->device);
75 if (part == NULL || mtd_partition_info(part, NULL, NULL, &write_size)) {
76 LOGE("Can't find %s\n", v->device);
77 return -1;
78 }
79
80 MtdReadContext *read = mtd_read_partition(part);
81 if (read == NULL) {
82 LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
83 return -1;
84 }
85
86 const ssize_t size = write_size * MISC_PAGES;
87 char data[size];
88 ssize_t r = mtd_read_data(read, data, size);
89 if (r != size) LOGE("Can't read %s\n(%s)\n", v->device, strerror(errno));
90 mtd_read_close(read);
91 if (r != size) return -1;
92
93 memcpy(out, &data[write_size * MISC_COMMAND_PAGE], sizeof(*out));
94 return 0;
95 }
set_bootloader_message_mtd(const struct bootloader_message * in,const Volume * v)96 static int set_bootloader_message_mtd(const struct bootloader_message *in,
97 const Volume* v) {
98 size_t write_size;
99 mtd_scan_partitions();
100 const MtdPartition *part = mtd_find_partition_by_name(v->device);
101 if (part == NULL || mtd_partition_info(part, NULL, NULL, &write_size)) {
102 LOGE("Can't find %s\n", v->device);
103 return -1;
104 }
105
106 MtdReadContext *read = mtd_read_partition(part);
107 if (read == NULL) {
108 LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
109 return -1;
110 }
111
112 ssize_t size = write_size * MISC_PAGES;
113 char data[size];
114 ssize_t r = mtd_read_data(read, data, size);
115 if (r != size) LOGE("Can't read %s\n(%s)\n", v->device, strerror(errno));
116 mtd_read_close(read);
117 if (r != size) return -1;
118
119 memcpy(&data[write_size * MISC_COMMAND_PAGE], in, sizeof(*in));
120
121 MtdWriteContext *write = mtd_write_partition(part);
122 if (write == NULL) {
123 LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
124 return -1;
125 }
126 if (mtd_write_data(write, data, size) != size) {
127 LOGE("Can't write %s\n(%s)\n", v->device, strerror(errno));
128 mtd_write_close(write);
129 return -1;
130 }
131 if (mtd_write_close(write)) {
132 LOGE("Can't finish %s\n(%s)\n", v->device, strerror(errno));
133 return -1;
134 }
135
136 LOGI("Set boot command \"%s\"\n", in->command[0] != 255 ? in->command : "");
137 return 0;
138 }
139
140
141 // ------------------------------------
142 // for misc partitions on block devices
143 // ------------------------------------
144
wait_for_device(const char * fn)145 static void wait_for_device(const char* fn) {
146 int tries = 0;
147 int ret;
148 struct stat buf;
149 do {
150 ++tries;
151 ret = stat(fn, &buf);
152 if (ret) {
153 printf("stat %s try %d: %s\n", fn, tries, strerror(errno));
154 sleep(1);
155 }
156 } while (ret && tries < 10);
157 if (ret) {
158 printf("failed to stat %s\n", fn);
159 }
160 }
161
get_bootloader_message_block(struct bootloader_message * out,const Volume * v)162 static int get_bootloader_message_block(struct bootloader_message *out,
163 const Volume* v) {
164 wait_for_device(v->device);
165 FILE* f = fopen(v->device, "rb");
166 if (f == NULL) {
167 LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
168 return -1;
169 }
170 struct bootloader_message temp;
171 int count = fread(&temp, sizeof(temp), 1, f);
172 if (count != 1) {
173 LOGE("Failed reading %s\n(%s)\n", v->device, strerror(errno));
174 return -1;
175 }
176 if (fclose(f) != 0) {
177 LOGE("Failed closing %s\n(%s)\n", v->device, strerror(errno));
178 return -1;
179 }
180 memcpy(out, &temp, sizeof(temp));
181 return 0;
182 }
183
set_bootloader_message_block(const struct bootloader_message * in,const Volume * v)184 static int set_bootloader_message_block(const struct bootloader_message *in,
185 const Volume* v) {
186 wait_for_device(v->device);
187 FILE* f = fopen(v->device, "wb");
188 if (f == NULL) {
189 LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
190 return -1;
191 }
192 int count = fwrite(in, sizeof(*in), 1, f);
193 if (count != 1) {
194 LOGE("Failed writing %s\n(%s)\n", v->device, strerror(errno));
195 return -1;
196 }
197 if (fclose(f) != 0) {
198 LOGE("Failed closing %s\n(%s)\n", v->device, strerror(errno));
199 return -1;
200 }
201 return 0;
202 }
203