to install ssh server on android https://play.google.com/store/apps/details?id=me.shkschneider.dropbears… first you need remount / as writable then manually create the the /usr/libexec directory and link /system/xbin/sftp-server. clean up by making / read only again.
root@android:/data/local # cat /proc/mounts rootfs / rootfs ro,relatime 0 0 tmpfs /dev tmpfs rw,nosuid,relatime,mode=755 0 0 .. snip .. root@android:/data/local # mount -o remount,rw rootfs / root@android:/data/local # mkdir /usr root@android:/data/local # mkdir /usr/libexec root@android:/data/local # ln -s /system/xbin/sftp-server /usr/libexec/ root@android:/data/local # mount -o remount,ro rootfs /
this will get nuked on reboot, so we need to put it in a script /data/local/userinit.sh (putting it in /data/local/userinit.d/ shold work but fails for unknow reason)
#!/system/xbin/bash mount -o remount,rw rootfs / mkdir -p /usr/libexec ln -s /system/xbin/sftp-server /usr/libexec/ mount -o remount,ro rootfs /