Generic script to mount partitions of an image file

I posted yesterday about a new EasyOS image file, with 'vmlinuz' and 'initrd' in the boot-partition, and 'easy.sfs' in the working-partition:

https://bkhome.org/news/202206/fast-first-time-bootup.html

The current documentation to update an installation, by the manual method, is to click on the new 'easy*.img' file, and then copy across the new 'vmlinuz', 'initrd' and 'easy.sfs', for example here:

https://easyos.org/user/easy-version-upgrade-and-downgrade.html

However, clicking on a 'easy*.img' file only mounts the first, vfat, boot-partition. The second ext4 working-partition also needs to be mounted, to get at the new 'easy.sfs'.

I have rewritten the image file mounting script, so that it can handle any .img file. It is /usr/sbin/mount-img and this is it:

#!/bin/sh
#passed in 1st param "mount" or "unmount"
#for mount, passed in 2nd param name of .img file. may include path.

Maction="$1"
[ "$Maction" != "mount" -a "$Maction" != "unmount" ] && exit

if [ "$Maction" == "mount" ];then
 ESPEC="$2"
 [ "$ESPEC" == "" ] && exit
 [ ! -f "$ESPEC" ] && exit
 
 xESPEC="$(echo -n "$ESPEC" | sed -e 's%-%\\-%g' -e 's%\.%\\.%g' -e 's%\+%\\+%g')"
 PARTS="$(fdisk -l --bytes ${ESPEC} | grep "^${xESPEC}" | tr -d '*' | tr -s ' ')"
 #ex: offset in sectors, size in bytes. before the pipe operations...
 #                      Boot Start   End    Sectors  Size    Id  Type
 #easy-4.0.3-amd64.img1 *     2048   32767   30720  15728640 ef EFI (FAT-12/16/32)
 #easy-4.0.3-amd64.img2      32768 1638399 1605632 822083584 83 Linux
 
 OFFs="$(echo "$PARTS" | cut -f 2 -d ' ' | tr '\n' ' ')"
 
 CNT=1
 for aOFFs in ${OFFs}
 do
  aOFFb=$(($aOFFs*512)) #assumption, 512 bytes per sector.
  LOOPn="$(losetup -f)"
  losetup -o ${aOFFb} ${LOOPn} ${ESPEC}
  aFS="$(blkid ${LOOPn} | tr ' ' '\n' | grep '^TYPE' | cut -f 2 -d '"' | grep -E 'vfat|ext|f2fs')"
  [ "$aFS" == "" ] && continue
  mkdir -p /tmp/mount-img-${CNT}-${aFS}-${LOOPn##*/}
  busybox mount -t ${aFS} ${LOOPn} /tmp/mount-img-${CNT}-${aFS}-${LOOPn##*/}
  rox -x -d /tmp/mount-img-${CNT}-${aFS}-${LOOPn##*/}
  CNT=$(($CNT+1))
 done
 exit
fi

#unmount...
for aMNT in `ls -d /tmp/mount-img-[1-9]-*`
do
 [ "$aMNT" == "" ] && continue
 [ ! -d "$aMNT" ] && continue
 aDIR="${aMNT##*/}"
 rox -D "$aMNT"
 sync
 busybox umount "$aMNT"
 rm -rf /tmp/$aDIR
 losetup -d /dev/${aDIR/*-/}
done

Works great, brings up two ROX-Filer windows, with both partitions. Next, have to do the association, so it will run when click on an img file in ROX-Filer. As before, the plan is can click on the .img file again to unmount.    

Tags: easy