Month: April 2008

I wanted try something other than JFFS2 as the rootfs and decided to go with UBIFS. Thanks to GIT’s brilliance I had no trouble pulling the UBIFS kernel patches from their tree to mine.

It seems that the UBIFS hasn’t had many NOR flash users before me and it needed some fixes. Artem Bityutskiy was extremely helpful in fixing the deficiencies and helping me out. After a few debug rounds I now have UBIFS root on my Gumstix.

I created the UBIFS image with the following commands:


sudo mkfs.ubifs --compr=zlib -r /tmp/rootfs -m 1 -e 130944 -c 120 -o ubifs.img
ubinize -o ubi.img -m 1 -p 128KiB -v ubinize.cfg


With this ubinize.cfg:


[ubifs]
mode=ubi
image=ubifs.img
vol_id=0
vol_size=13MiB
vol_type=dynamic
vol_name=rootfs
vol_alignment=1
vol_flags=autoresize


Note that I have reserved 2MiB for the kernel partition.

I had to add one extra parameter to the kernel args to specify what MTD partition I wanted to use:

console=ttyS0,115200n8 root=ubi0:rootfs rootfstype=ubifs reboot=cold,hard ubi.mtd=1


Now my Gumstix boots with simplified kernel to busybox shell in roughly 4.2 seconds (counted from the bootm command in U-Boot).

I had to add a new category after all: gumstix. The embedded word has too broad a meaning.

Updating the kernel wasn’t such a big thing after all, even for a kernel n00b like me. I git cloned the vanilla tree from kernel.org and patched the generic (and one bluetooth) Gumstix patches from OE: arch-config.patch, board-init.patch, header.patch, mach-types-fix.patch, modular-init-bluetooth.patch, tsc2003-config.diff, tsc2003.c, and uImage-in-own-partition.patch. Most of them applied fine, I just had to manually apply simple Makefile patches and change pxa_init_irq call to pxa27x_init_irq.

I don’t know if it really works, but at least it booted:


root@gumstix-custom-verdex:~$ uname -a
Linux gumstix-custom-verdex 2.6.25-rc8-00151-gdc41023 #2 Fri Apr 4 23:43:25 EEST 2008 armv5tel unknown