Change Kernel

[HenningA]

Hi,

I'm want to use a newer kernel than the one on the debian image. I added the cubieboard repository and downloaded the kernel package. It's version 3.4.79, and the modules have there own folder under /lib/modules

I'm going to replace the uimage on the sd-card with the new kernel. What I'm looking for is the config-file for uboot where the modules folder is specified so I can change it. Does anybody know where this file is on den olimex debian image?

Another nice thing would be to be able to choose the kernel on startup like with grub. Is there a way to do this?

Thx, Henning

[progmetalbg]

U-Boot is not like the boot loaders that you know from x86 Linux world such as grub or lilo.
You can check u-boot sunxi wiki for more info: https://github.com/linux-sunxi/u-boot-sunxi/wiki
and Olimex blog post about building your own image from scratch: http://olimex.wordpress.com/2013/09/18/7795/

[HenningA]

I figured it out.

I was looking for the uEnv.txt file, but  there wasn't any on the locations mentioned in the uboot wiki.

So I just tried to copy the uImage-File from the kernel-package to the boot partition of the sd-card. And tada it works. Kernel 3.4.79 is running.

Henning

[Tar]

Hi,

the uEnv file may be used to pass additional parameters to the kernel, like you would do with grub.

I tried the same to put my system into the NAND-Flash, but I lost the touchscreen capabilities and have no idea, why.

i`d love to combine both.

EDIT: i was too tired. the needed module sun4i-ts has to be loaded manually. Olimex compiled it in. But nevertheless - the UEXT patch is missing from patwoods kernel.

Tar

[HenningA]

How much faster is the system when running it from flash compared to the SD-card? I'm thinking of using the flash as root-partition.

[Tar]

Hi Henning,

just now, my Olinuxino runs from SD-Card. I also have a Cubietruck, which is running on Flash.

But for short - some rude values:
root@anor:/home/olimex# dd if=/dev/mmcblk0 of=/dev/null bs=4096 count=100k skip=100k
102400+0 records in
102400+0 records out
419430400 bytes (419 MB) copied, 22.412 s, 18.7 MB/s
root@anor:/home/olimex# dd if=/dev/nand of=/dev/null bs=4096 count=100k skip=100k
102400+0 records in
102400+0 records out
419430400 bytes (419 MB) copied, 37.7682 s, 11.1 MB/s

On the Cubie:
root@morgul:/home/cubie# dd if=/dev/mmcblk0 of=/dev/null bs=4096 count=100k skip=100k
102400+0 records in
102400+0 records out
419430400 bytes (419 MB) copied, 21.9496 s, 19.1 MB/s
root@morgul:/home/cubie# dd if=/dev/nand of=/dev/null bs=4096 count=100k skip=100k
102400+0 records in
102400+0 records out
419430400 bytes (419 MB) copied, 28.6027 s, 14.7 MB/s

The NAND is not always better..

[HenningA]

Hi Tar,

thank you for the infos. I expected the NAND would be much faster.

I tried on my 80gig 2.5" hard-disk (~6 years old):read speed is 40MB/s

So it's better to move the root file system to the hard disk...