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      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 
     29 static int get_bootloader_message_mtd(struct bootloader_message *out, const Volume* v);
     30 static int set_bootloader_message_mtd(const struct bootloader_message *in, const Volume* v);
     31 static int get_bootloader_message_block(struct bootloader_message *out, const Volume* v);
     32 static int set_bootloader_message_block(const struct bootloader_message *in, const Volume* v);
     33 
     34 int 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 
     49 int 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 
     68 static const int MISC_PAGES = 3;         // number of pages to save
     69 static const int MISC_COMMAND_PAGE = 1;  // bootloader command is this page
     70 
     71 static 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 }
     97 static 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 
    146 static 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 
    163 static 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 
    185 static 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