Android Recovery 代码分析
Android Recovery 代码分析
1、调用main函数
在gingerbread/bootable/recovery/recovery.c最下面有个main(),这是recovery应用的主入口,当编译recovery的时候,会生成一个名为recovery的可执行文件,我这边是放在out/目录下recovery/文件系统的/sbin目录下,调用recovery可执行文件时会传入参数,这些参数就是main函数的参数,如下
- int
- main(int argc, char **argv)
- {
- char tmp[4];
- time_t start = time(NULL);
- #if RECOVERY_DBG
- log_init();
- #endif
- INFO(">>>>> Enter recovery <<<<<\n");
从这里开始了recovery...
2、获取commond
- static void
- get_args(int *argc, char ***argv) {
- // INFO("Enter get_args\n");
- struct bootloader_message boot;
- memset(&boot, 0, sizeof(boot));
3、获取默认升级固件路径和名称
int property_get(const char *key, char *value, const char *default_value);
包括U盘、SD卡和Flash升级
4、解析命令
int getopt_long(int, char * const *, const char *, const struct option *, int *);
如 case 's': send_intent = optarg; break;
optarg是取命令中等号后面字符串
注册一些命令,register_update_commands函数是注册在update-script和recovery-script使用的升级命令
初始化一个变量,int status = INSTALL_SUCCESS;这个变量是用来标识升级是否成功,在清除misc分区命令时候作为一个判断依据
5、升级、格式化、还原
接下来,有三种需求,一是factorytest;二是update、recover;三是wipe data
- if (update_image != NULL) {
- status = install_update(update_image);
- if (status != 0) {
- ui_set_background(BACKGROUND_ICON_ERROR);
- if(status==-1) g_enable_item_move = false;
- }
- }else if(recover_image != NULL){
- atus = recover_backup(recover_image);
- if (status != 0) {
- ui_set_background(BACKGROUND_ICON_ERROR);
- if(status==-1) g_enable_item_move = false;
- }
- }
- if (wipe_flags) {
- if( wipe_data(wipe_flags) != 0 )
- {
- status = INSTALL_ERROR;
- ui_print("Data wipe failed.\n");
- // 不擦除misc中的命令,重启后再次格式化
- g_reset_blmsg = false;
- g_enable_item_move = false;
- }
- }
- for (;;) {
- int key = 0;
- INFO("wait an key\n");
- key = ui_wait_key();
- INFO("end wait\n");
- // Reset the bootloader message to revert to a normal main system boot.
- if(g_reset_blmsg)
- {
- INFO("ready to clear cmd in misc \n");
- struct bootloader_message boot;
- memset(&boot, 0, sizeof(boot));
- set_bootloader_message(&boot);
- }
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