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 <fs_mgr.h>
18#include "bootloader.h"
19#include "common.h"
20#include "mtdutils/mtdutils.h"
21#include "roots.h"
22
23#include <errno.h>
24#include <stdio.h>
25#include <string.h>
26#include <sys/stat.h>
27#include <unistd.h>
28
29static int get_bootloader_message_mtd(struct bootloader_message *out, const Volume* v);
30static int set_bootloader_message_mtd(const struct bootloader_message *in, const Volume* v);
31static int get_bootloader_message_block(struct bootloader_message *out, const Volume* v);
32static int set_bootloader_message_block(const struct bootloader_message *in, const Volume* v);
33
34int get_bootloader_message(struct bootloader_message *out) {
35    Volume* v = volume_for_path("/misc");
36    if (v == NULL) {
37      LOGE("Cannot load volume /misc!\n");
38      return -1;
39    }
40    if (strcmp(v->fs_type, "mtd") == 0) {
41        return get_bootloader_message_mtd(out, v);
42    } else if (strcmp(v->fs_type, "emmc") == 0) {
43        return get_bootloader_message_block(out, v);
44    }
45    LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
46    return -1;
47}
48
49int set_bootloader_message(const struct bootloader_message *in) {
50    Volume* v = volume_for_path("/misc");
51    if (v == NULL) {
52      LOGE("Cannot load volume /misc!\n");
53      return -1;
54    }
55    if (strcmp(v->fs_type, "mtd") == 0) {
56        return set_bootloader_message_mtd(in, v);
57    } else if (strcmp(v->fs_type, "emmc") == 0) {
58        return set_bootloader_message_block(in, v);
59    }
60    LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
61    return -1;
62}
63
64// ------------------------------
65// for misc partitions on MTD
66// ------------------------------
67
68static const int MISC_PAGES = 3;         // number of pages to save
69static const int MISC_COMMAND_PAGE = 1;  // bootloader command is this page
70
71static int get_bootloader_message_mtd(struct bootloader_message *out,
72                                      const Volume* v) {
73    size_t write_size;
74    mtd_scan_partitions();
75    const MtdPartition *part = mtd_find_partition_by_name(v->blk_device);
76    if (part == NULL || mtd_partition_info(part, NULL, NULL, &write_size)) {
77        LOGE("Can't find %s\n", v->blk_device);
78        return -1;
79    }
80
81    MtdReadContext *read = mtd_read_partition(part);
82    if (read == NULL) {
83        LOGE("Can't open %s\n(%s)\n", v->blk_device, strerror(errno));
84        return -1;
85    }
86
87    const ssize_t size = write_size * MISC_PAGES;
88    char data[size];
89    ssize_t r = mtd_read_data(read, data, size);
90    if (r != size) LOGE("Can't read %s\n(%s)\n", v->blk_device, strerror(errno));
91    mtd_read_close(read);
92    if (r != size) return -1;
93
94    memcpy(out, &data[write_size * MISC_COMMAND_PAGE], sizeof(*out));
95    return 0;
96}
97static int set_bootloader_message_mtd(const struct bootloader_message *in,
98                                      const Volume* v) {
99    size_t write_size;
100    mtd_scan_partitions();
101    const MtdPartition *part = mtd_find_partition_by_name(v->blk_device);
102    if (part == NULL || mtd_partition_info(part, NULL, NULL, &write_size)) {
103        LOGE("Can't find %s\n", v->blk_device);
104        return -1;
105    }
106
107    MtdReadContext *read = mtd_read_partition(part);
108    if (read == NULL) {
109        LOGE("Can't open %s\n(%s)\n", v->blk_device, strerror(errno));
110        return -1;
111    }
112
113    ssize_t size = write_size * MISC_PAGES;
114    char data[size];
115    ssize_t r = mtd_read_data(read, data, size);
116    if (r != size) LOGE("Can't read %s\n(%s)\n", v->blk_device, strerror(errno));
117    mtd_read_close(read);
118    if (r != size) return -1;
119
120    memcpy(&data[write_size * MISC_COMMAND_PAGE], in, sizeof(*in));
121
122    MtdWriteContext *write = mtd_write_partition(part);
123    if (write == NULL) {
124        LOGE("Can't open %s\n(%s)\n", v->blk_device, strerror(errno));
125        return -1;
126    }
127    if (mtd_write_data(write, data, size) != size) {
128        LOGE("Can't write %s\n(%s)\n", v->blk_device, strerror(errno));
129        mtd_write_close(write);
130        return -1;
131    }
132    if (mtd_write_close(write)) {
133        LOGE("Can't finish %s\n(%s)\n", v->blk_device, strerror(errno));
134        return -1;
135    }
136
137    LOGI("Set boot command \"%s\"\n", in->command[0] != 255 ? in->command : "");
138    return 0;
139}
140
141
142// ------------------------------------
143// for misc partitions on block devices
144// ------------------------------------
145
146static void wait_for_device(const char* fn) {
147    int tries = 0;
148    int ret;
149    struct stat buf;
150    do {
151        ++tries;
152        ret = stat(fn, &buf);
153        if (ret) {
154            printf("stat %s try %d: %s\n", fn, tries, strerror(errno));
155            sleep(1);
156        }
157    } while (ret && tries < 10);
158    if (ret) {
159        printf("failed to stat %s\n", fn);
160    }
161}
162
163static int get_bootloader_message_block(struct bootloader_message *out,
164                                        const Volume* v) {
165    wait_for_device(v->blk_device);
166    FILE* f = fopen(v->blk_device, "rb");
167    if (f == NULL) {
168        LOGE("Can't open %s\n(%s)\n", v->blk_device, strerror(errno));
169        return -1;
170    }
171    struct bootloader_message temp;
172    int count = fread(&temp, sizeof(temp), 1, f);
173    if (count != 1) {
174        LOGE("Failed reading %s\n(%s)\n", v->blk_device, strerror(errno));
175        return -1;
176    }
177    if (fclose(f) != 0) {
178        LOGE("Failed closing %s\n(%s)\n", v->blk_device, strerror(errno));
179        return -1;
180    }
181    memcpy(out, &temp, sizeof(temp));
182    return 0;
183}
184
185static int set_bootloader_message_block(const struct bootloader_message *in,
186                                        const Volume* v) {
187    wait_for_device(v->blk_device);
188    FILE* f = fopen(v->blk_device, "wb");
189    if (f == NULL) {
190        LOGE("Can't open %s\n(%s)\n", v->blk_device, strerror(errno));
191        return -1;
192    }
193    int count = fwrite(in, sizeof(*in), 1, f);
194    if (count != 1) {
195        LOGE("Failed writing %s\n(%s)\n", v->blk_device, strerror(errno));
196        return -1;
197    }
198    if (fclose(f) != 0) {
199        LOGE("Failed closing %s\n(%s)\n", v->blk_device, strerror(errno));
200        return -1;
201    }
202    return 0;
203}
204