客户预置了一些资源在内置的/data/media/0/目录下，但是恢复出厂设置会把data给清掉，需要在恢复出厂设置时不删除掉/data/media/0/的特定文件:

大致有两种思路：

1.将需要保留的目录在删除前复制到另外一个分区，比如cache分区，格式化完data分区再移动回来。

2.恢复出厂设置的操作不要执行格式化，而是执行命令rm，只删除需要删除的目录，其他目录保留。

由于abc目录文件较大，差不多2G，思路1由于找不到分区暂存，故现采用思路2。

修改bootable/recovery/recovery.c里面对data分区清除的代码：

static bool wipe_data(int should_confirm, Device* device) {

if (should_confirm && !yes_no(device, "Wipe all user data?", " THIS CAN NOT BE UNDONE!")) {

return false;

}

modified_flash = true;

ui->Print("\n-- Wiping data...\n");

bool success =

device->PreWipeData() &&

erase_volume("/data") &&

erase_volume("/cache") &&

device->PostWipeData();

ui->Print("Data wipe %s.\n", success ? "complete" : "failed");

return success;

}

static bool erase_volume(const char* volume) {

bool is_cache = (strcmp(volume, CACHE_ROOT) == 0);

...

ensure_path_unmounted(volume);

result = format_volume(volume);改成：

int result = 0;

if(is_cache) {

ensure_path_unmounted(volume);

result = format_volume(volume);

} else {

ensure_path_mounted(volume);

system("cd /data/media/; busybox mv 0/abc/ ./; busybox rm -rf `busybox ls -a | busybox egrep -v abc`");//reserve abc

//system("cd /data/media/; busybox rm -rf `busybox ls -a | busybox egrep -v 0`");//reserve 0

system("cd /data/; busybox rm -rf `busybox ls -a | busybox egrep -v media`");//reserve media

}备注：

刚开始代码是这样写的：

int result = 0;

if(is_cache) {

ensure_path_unmounted(volume);

result = format_volume(volume);

} else {

ensure_path_mounted(volume);

system("cd /data/media/0/; busybox rm -rf `busybox ls -a | busybox egrep -v abc`");//reserve abc

system("cd /data/media/; busybox rm -rf `busybox ls -a | busybox egrep -v 0`");//reserve 0

system("cd /data/; busybox rm -rf `busybox ls -a | busybox egrep -v media`");//reserve media

}后来发现系统起来后会自动把/data/media/0/abc变成/data/media/0/0/abc，也就是多了一层0，后来改成了：

int result = 0;

if(is_cache) {

ensure_path_unmounted(volume);

result = format_volume(volume);

} else {

ensure_path_mounted(volume);

system("cd /data/media/; busybox mv 0/abc/ ./; busybox rm -rf `busybox ls -a | busybox egrep -v abc`");//reserve abc

//system("cd /data/media/; busybox rm -rf `busybox ls -a | busybox egrep -v 0`");//reserve 0

system("cd /data/; busybox rm -rf `busybox ls -a | busybox egrep -v media`");//reserve media

}

测试又发现system函数在recovery里面好像执行不成功，查了一下system函数，有以下介绍：

The system() library function uses fork(2) to create a child process that executes the shell command specified in command using execl(3) as follows:

execl("/bin/sh", "sh", "-c", command, (char *) 0);

应该是由于recovery模式下没有/bin/sh这个指令导致的，所以又改成以下方式：

ensure_path_mounted(volume);

//system("cd /data/media/; busybox mv 0/abc/ ./; busybox rm -rf `busybox ls -a | busybox egrep -v abc`");//reserve abc

//system("cd /data/; busybox rm -rf `busybox ls -a | busybox egrep -v media`");//reserve media

result = rename("/data/media/0/abc", "/data/media/abc");

if(result) {

ui->Print("rename : %s", strerror(errno));

result = 0;

}

remove_files("/data/media", "abc");

remove_files("/data", "media");

其中remove_files函数如下：

void remove_files(const char *dir, const char *except_dir)

{

DIR *dp;

struct dirent *entry;

struct stat s;

// check the parameter !

if( NULL == dir )

{

ui->Print(" dir is null ! ");

return;

}

// check if dir_name is a valid dir

lstat( dir , &s );

if( ! S_ISDIR( s.st_mode ) )

{

ui->Print("dir is not a valid directory !");

return;

}

//ui->Print("%s", dir);

if((dp = opendir(dir)) == NULL)

{

ui->Print("can't open dir.");

return;

}

chdir (dir);

while((entry = readdir(dp)) != NULL)

{

//ui->Print("%s : %d", entry->d_name, entry->d_type);

if(strcmp(entry->d_name,".")==0 || strcmp(entry->d_name,"..")==0)

continue;

if(strcmp(entry->d_name, except_dir) == 0)

continue;

//ui->Print("%s : %d", entry->d_name, entry->d_type);

if(remove(entry->d_name))

ui->Print("remove %s : %s.\n", entry->d_name, strerror(errno));

}

chdir("..");

closedir(dp);

}

又发现remove函数无法删除非空目录，最后代码又做了调整：

void remove_files(const char *dir, const char *except_dir)

{

DIR *dp;

struct dirent *entry;

struct stat s;

pid_t pid;

//char cmd[128];

// check the parameter !

if( NULL == dir )

{

ui->Print(" dir is null ! ");

return;

}

// check if dir_name is a valid dir

lstat( dir , &s );

if( ! S_ISDIR( s.st_mode ) )

{

ui->Print("dir is not a valid directory !");

return;

}

//ui->Print("%s", dir);

if((dp = opendir(dir)) == NULL)

{

ui->Print("can't open dir.");

return;

}

chdir (dir);

while((entry = readdir(dp)) != NULL)

{

//ui->Print("%s : %d", entry->d_name, entry->d_type);

if(strcmp(entry->d_name,".")==0 || strcmp(entry->d_name,"..")==0)

continue;

if(strcmp(entry->d_name, except_dir) == 0)

continue;

//ui->Print("%s : %d", entry->d_name, entry->d_type);

if(remove(entry->d_name))

{

ui->Print("remove %s : %s.\n", entry->d_name, strerror(errno));

//snprintf(cmd, sizeof(cmd), "rm -rf %s", entry->d_name);

//printf("cmd: %s\n", buf);

if ((pid = fork()) < 0) {

printf("fork error\n");

} else if (pid == 0) {

execl("/sbin/busybox", "rm", "-rf", entry->d_name, (char *)0);

exit(127);

}

}

}

chdir("..");

closedir(dp);

}

实测OK。