Note: In the following code, the shell commands that start with # are the shell commands to be executed, and the others are the printed results. #Represents that you need to use ROOT permission (su) to execute, so if you want to modify a directory on your android phone to be mounted as read and write, you first need ROOT permission!
First get the full name of the system partition
#adb shell
# mount
rootfs / rootfs ro 0 0
tmpfs /dev tmpfs rw,mode=755 0 0
devpts /dev/pts devpts rw,mode=600 0 0
proc /proc proc rw 0 0
sysfs /sys sysfs rw 0 0
tmpfs /sqlite_stmt_journals tmpfs rw,size=4096k 0 0
none /dev/cpuctl cgroup rw,cpu 0 0
/dev/block/mtdblock0 /system yaffs2 ro 0 0 /dev/block/mtdblock1 /data yaffs2 rw,nosuid,nodev 0 0 /dev/block/mtdblock2 /cache yaffs2 rw,nosuid,nodev 0 0 /dev/block//vold/179:0 /sdcard vfat rw,dirsync,nosuid,nodev,noexec,uid=1000 ,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0It can be seen from the red part above/ The authority of the system is ro, which means read only.
# mount -o remount /dev/block/mtdblock0 /system
# mount
rootfs / rootfs ro 0 0
tmpfs /dev tmpfs rw,mode=755 0 0
devpts /dev/pts devpts rw,mode=600 0 0
proc /proc proc rw 0 0
sysfs /sys sysfs rw 0 0
tmpfs /sqlite_stmt_journals tmpfs rw,size=4096k 0 0
none /dev/cpuctl cgroup rw,cpu 0 0
/dev/block/mtdblock0 /system yaffs2 rw 0 0/dev/block/mtdblock1 /data yaffs2 rw,nosuid,nodev 0 0 /dev/block/mtdblock2 /cache yaffs2 rw,nosuid,nodev 0 0 /dev/block//vold/179:0 /sdcard vfat rw,dirsync,nosuid,nodev,noexec,uid=1000,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0 已经修改完成 如果要改回去ro
#mount -o remount,ro /dev/block/mtdblock0 /system
当/system 目录为RW权限后，您就可以随意删除或者替换系统应用了。可能您替换程序后还需要执行
$chmod 644 /system/app/您的程序.apk
$代表一般权限，无需ROOT权限即可执行的命令。执行此命令后您的APK才能获得执行权限，否则默认是无法执行的，程序在system/app目录不显示图标，那说明它没有执行权限