If you want to install via SDcard , first save the packages to the SDcard FAT Partition (I used /Packages/ dir).
Then, plug the SDcard into the DominoIO, and run the command below (opkg install):
cd /mnt/SDP1_FAT/Packages
root@domino:/mnt/SDP1_FAT/Packages# opkg install e2fsprogs_1.42.4-1_ar71xx.ipk libext2fs_1.42.4-1_ar71xx.ipk libcom_err_1.42.4-1_ar71xx.ipk
Installing e2fsprogs (1.42.4-1) to root...
Installing libext2fs (1.42.4-1) to root...
Installing libcom_err (1.42.4-1) to root...
Package libext2fs (1.42.4-1) installed in root is up to date.
Package libcom_err (1.42.4-1) installed in root is up to date.
Configuring libcom_err.
Configuring libext2fs.
Configuring e2fsprogs.
But, I could not find libcom_err.so.0 - so I linked it:
root@domino:/mnt# ln -s /usr/lib/libcom_err.so.2 /usr/lib/libcom_err.so.0
This gave me mke2fs, so now, with fdisk, I can make 2 partitions on the SDCard: FAT and Linux.