a mi al poner las lineas finales me deniega el acceso.
C:\Program Files\Xiaomi\MiPhone\Google\Android>adb shell
shell@cancro:/ $ su
su
/system/bin/sh: su: not found
127|shell@cancro:/ $ su
su
/system/bin/sh: su: not found
127|shell@cancro:/ $ dd if=/dev/block/mmcblk0p12 of=/sdcard/mmcblk0p12
dd if=/dev/block/mmcblk0p12 of=/sdcard/mmcblk0p12
/dev/block/mmcblk0p12: cannot open for read: Permission denied
1|shell@cancro:/ $ dd if=/dev/block/mmcblk0p13 of=/sdcard/mmcblk0p13
dd if=/dev/block/mmcblk0p13 of=/sdcard/mmcblk0p13
/dev/block/mmcblk0p13: cannot open for read: Permission denied
1|shell@cancro:/ $ dd if=/dev/block/mmcblk0p16 of=/sdcard/mmcblk0p16
dd if=/dev/block/mmcblk0p16 of=/sdcard/mmcblk0p16
/dev/block/mmcblk0p16: cannot open for read: Permission denied
1|shell@cancro:/ $