root@am64xx-evm:~# uname -a
Linux am64xx-evm 5.10.41-g4c2eade9f7 #1 SMP PREEMPT Tue Aug 10 21:52:40 UTC 2021 aarch64 aarch64 aarch64 GNU/Linux
root@am64xx-evm:~# ls -l /dev/mmcblk*
brw-rw---- 1 root disk 179, 32 Aug 10 22:07 /dev/mmcblk0
brw-rw---- 1 root disk 179, 64 Aug 10 22:10 /dev/mmcblk0boot0
brw-rw---- 1 root disk 179, 96 Aug 10 22:07 /dev/mmcblk0boot1
brw-rw---- 1 root disk 179, 33 Aug 10 22:07 /dev/mmcblk0p1
crw------- 1 root root 237,  0 Aug 10 22:07 /dev/mmcblk0rpmb
brw-rw---- 1 root disk 179,  0 Aug 10 22:07 /dev/mmcblk1
brw-rw---- 1 root disk 179,  1 Aug 10 22:07 /dev/mmcblk1p1
brw-rw---- 1 root disk 179,  2 Aug 10 22:07 /dev/mmcblk1p2
root@am64xx-evm:~# lsblk -b /dev/mmcblk0p1
NAME      MAJ:MIN RM        SIZE RO TYPE MOUNTPOINT
mmcblk0p1 179:33   0 15913155072  0 part /run/media/mmcblk0p1
root@am64xx-evm:~# lsblk -b /dev/mmcblk0boot0
NAME         MAJ:MIN RM     SIZE RO TYPE MOUNTPOINT
mmcblk0boot0 179:64   0 33030144  1 disk 
root@am64xx-evm:~# cat /sys/block/mmcblk0boot0/force_ro
1
root@am64xx-evm:~# echo 0 > /sys/block/mmcblk0boot0/force_ro
root@am64xx-evm:~# cat /sys/block/mmcblk0boot0/force_ro
0
root@am64xx-evm:~# lsblk -b /dev/mmcblk0boot0
NAME         MAJ:MIN RM     SIZE RO TYPE MOUNTPOINT
mmcblk0boot0 179:64   0 33030144  0 disk 
root@am64xx-evm:~# echo 1 > /sys/block/mmcblk0boot0/force_ro
root@am64xx-evm:~# cat /sys/block/mmcblk0boot0/force_ro
1
root@am64xx-evm:~# lsblk -b /dev/mmcblk0boot0
NAME         MAJ:MIN RM     SIZE RO TYPE MOUNTPOINT
mmcblk0boot0 179:64   0 33030144  1 disk 
root@am64xx-evm:~#