Finally worked it out, thanks for
uboot and
j0534ng31's help.
Now I can replace any fonts of /ebook, including the system UI fonts.
Code:
#!/system/bin/sh
mkdir /data/altsd
mount -o noatime,utf8 -t vfat /dev/block/mmcblk2p4 /data/altsd
afd=/data/altsd/altfonts/
fts=`ls $afd`
for ft in $fts
do
mount -o bind $afd$ft /ebook/fonts/$ft
done
Why not mount to /mnt/sdcard directly? Because if mounted to /mnt/sdcard, sometime later, when the system do the mount procedure, will got faliure because /mnt/sdcard was already occupied, and some related action will not be done. To avoid this, I mount to another directory.
As to
VDC, I guess that it has not been initialized when the install-recovey.sh is running.