How to write recovery command to misc.img at Android?

busybee

Do  a hexdump of misc.img, and you'll find the magic word:

1. $ hexdump -C rkst/Image/misc.img
   
2. 00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
   
3. *
   
4. 00004000  62 6f 6f 74 2d 72 65 63  6f 76 65 72 79 00 00 00  |boot-recovery...|
   
5. 00004010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
   
6. *
   
7. 00004040  72 65 63 6f 76 65 72 79  0a 2d 2d 77 69 70 65 5f  |recovery.--wipe_|
   
8. 00004050  61 6c 6c 00 00 00 00 00  00 00 00 00 00 00 00 00  |all.............|
   
9. 00004060  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
   
10. *
    
11. 0000c000

Copy the code

Please refer to https://bitbucket.org/T-Firefly/firefly ... 0462265ae6

There's a command to write misc partition:

1. (echo -n boot-recovery | busybox dd bs=16k seek=1 conv=sync; busybox dd if=/dev/zero bs=16k count=1) > /dev/block/mtd/by-name/misc
   

Copy the code

busybee

Check the commit already mensioned above.

https://bitbucket.org/T-Firefly/firefly ... 0462265ae6

This commit a based on the fact that misc partition is writable by all users:

diff --git a/system/core/init/devices.c b/system/core/init/devices.c
index 537627e..88287ef 100644
--- a/system/core/init/devices.c
+++ b/system/core/init/devices.c
@@ -188,7 +188,7 @@ static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid)
     /* Default if nothing found. */
     *uid = 0;
     *gid = 0;
-    return 0600;
+    return 0666;
}

static void make_device(const char *path,

It's somewhat ugly. Please follow the factory reset code in Setting.