Installing on an ARM mini (7in) netbook.

[dogboy]

8/21/2011

I have an ARM (WM8505 SOC based ) 7 inch "netbook" and I was able to
get Arch Linux running on it. I thought I would describe how to do
that here in case others are interested in the same thing.

The only tricky part was getting the kernel for it. The mainline
kernel.org code doesn't have all the support in it yet for these type of
netbooks so I had to get it from elsewhere. Plus other supporting
pieces had to be put together to get it running.

Briefly, an SD card will be used to contain the Linux install. The
first partition of the SD card will be used to contain the boot
'scripts' and the kernel. The netbook firmware looks on the first
SD card partition and if it finds the proper script files there, it will
execute them and this will start the kernel running.

========================================================================
What is needed:

0) An SDHC card (plain SD might work -- but didn't try one...). Mine is
4Gig and I partitioned and formatted it as follows:

Command (m for help): p

Disk /dev/sdc: 3951 MB, 3951034368 bytes
122 heads, 57 sectors/track, 1109 cylinders
Units = cylinders of 6954 * 512 = 3560448 bytes
Disk identifier: 0x1feeeff9

Device Boot Start End Blocks Id System
/dev/sdc1 1 9 31264+ b W95 FAT32
/dev/sdc2 10 572 1957551 83 Linux
/dev/sdc3 573 798 785802 82 Linux swap / Solaris
/dev/sdc4 799 1109 1081347 83 Linux

Formatted partition 1 as FAT, 2 as ext2, 3 as swap and 4 as ext3


1) fatpart.tgz: wget http://crux-arm.nu/files/devices/wm8505/fatpart.tgz

This provides the boot script files needed to boot Linux on the device. The
firmware on the netbook looks for these script files on the first
(needs to be FAT FS) partition of the SD card and, if found, executes
them. The commands in these scripts load the kernel and start it running.

There is also a kernel (uzImage.bin) in this tarball. However it
is old, doesn't work for this, and I replace it with a more current one.

2) Kernel code from http://gitorious.org/linux-on-via-vt8500

The site has work in progress kernel code for the wm8505/vt8500 netbooks.
It's tarball naming implies it is 2.6.35 based but I found that it is actually
looks like it is kept reasonably current with the mainline kernel code.

3) kernel config file. (mine is attached).

This config works with my flavor netbook but may not on others. Adapt it
for your specific HW or just roll your own however you like.

4) The Arch Linux ARM 'tarball':
wget http://archlinuxarm.org/os/ArchLinuxARM ... est.tar.gz

I did an install with both the 'latest' and June 2011 versions of the
tarball. Both worked ok.

========================================================================
What to do:

1) (Cross) Build the initial kernel.

The tricky part to getting it running is that there is no kernel
for the netbook in the Arch tarball. So, I initially used the
ELDK-5.0 tool kit to cross build a kernel (used 'make uImage') using
the kernel source from gitorious and my kernel config file. Once the netbook
was booting, I then rebuilt the kernel natively on my netbook and
began using a native built kernel instead.

After build, the needed kernel file is found in ./arch/arm/boot/uImage.

2) Load SD card partition 1 (boot partition)

On host machine, mkdir /mnt/loadit and then mount partition 1
of the SD card as /mnt/loadit and cd to /mnt/loadit.

Extract the fatpart.tgz file into the partition... tar xvfzp fatpart.tgz
(from wherever it is). cd down to the script directory and
then mv uzImage.bin orig.uzImage.bin (just in case you want it later...)
and then cp uImage uzImage.bin (from wherever your kernel uImage file is.)

cd out of /mnt/loadit and unmount it.

3) Load SD card partition 2 (root partition)

Again, do on host machine...

Mount SD card partition 2 (root partition) as /mnt/loadit and
cd to /mnt/loadit.

Then extract the Arch Linux tarball:
tar xvfzp ArchLinuxARM-armv5te-latest.tar.gz (from wherever it lives).

(My kernel doesn't have any crucial modules so I just skipped installing
modules until later when I built it natively.)

Edit /mnt/loadit/etc/fstab and modify it to match the SD card partitions:

#
# /etc/fstab: static file system information
#
# <file system> <dir> <type> <options> <dump> <pass>
/dev/mmcblk0p1 /boot vfat defaults 0 0
/dev/mmcblk0p2 / ext2 defaults 0 0
/dev/mmcblk0p3 swap swap defaults 0 0
/dev/mmcblk0p4 /home ext3 defaults 0 0
devpts /dev/pts devpts defaults 0 0
none /sys sysfs defaults 0 0
none /proc proc defaults 0 0
#tmp /tmp tmpfs defaults 0 0
shm /dev/shm tmpfs defaults 0 0
#usb /proc/bus/usb usbfs defaults 0 0


Edit /mnt/loadit/etc/inittab. I shut off the ttyS0 agetty since
my netbook does not have a serial port.

cd out of /mnt/loadit and umount it.

4) Transfer SD card to netbook.

Make sure all SD card partitions are unmounted and then put the
SD card into the netbook SD card slot. Connect the netbook ethernet
port to the network and power the netbook on.

Should boot to a prompt. Will complain about missing modules but
will boot ok.

Login as root. Then install the needed compile tools by doing:

pacman -Sy base-devel file which linux-api-headers uboot-mkimage

Numerous things are updated. I rebooted it after the updates finished
(rebooting is probably not needed but I'm paranoid so I do.)

Get a copy of the kernel code tarball and config file onto the
netbook. Unpack the kernel tarball and cd into it. Do a
'make mrproper' and then copy the config file to '.config'. Do
'make oldconfig' and then 'make uImage' and then 'make modules_install'.

Then 'cp -f arch/arm/boot/uImage /boot/script/uzImage.bin' (SD card
partition 1 should be mounted as /boot...)

It took about 4 hours to rebuild the kernel natively on the netbook
(it's a slow 300Mhz...).

Then reboot and it will restart on the native built kernel.

Done.

Networking, USB flash sticks, USB keyboard all work....
I don't know if sound and wireless work cause I don't use those.

The only oddity that I've found is that the RTC seems to work
fine unless it gets out of whack (like if the netbook battery runs completely
out...). Then linux doesn't seem to be able to set the date. In that
situation, I've had to reboot into Windows CE and reset the RTC with it
for it to work again with Linux.

The netbooks come with Windows CE pre-installed in the netbooks builtin
storage. Linux runs from the SD card, and this install does not
displace CE. So, (unless you do something that corrupts the CE storage
device) you can get back into CE by powering down, removing
the SD card and then starting it back up.

[dogboy]

My config file attachment didn't work.... If someone wants a copy, PM me and I'll email it.

[rewind]

Hi there, I'll be very grateful if you send me your kernel configuration file. As a complete newbie with arm maybe a small how-to cross build the kernel for wm8505/vt8500 will be very helpful. If you have already built it for Jaytech 9901 or similar netbook can you upload the uzlimage.bin somewhere ?

[OdinJones]

Out of curiosity, could you link where you purchased this netbook?

[rewind]

A friend of mine asked me to try to get rid of the German Windows CE 6, because he didn't know a word in Deutsch. It's definitely not bought from around here /I'm in Bulgaria/.

[dogboy]

Ok, attaching it as a .gz file worked. So, my config file is now attached to this post.

I bought it off ebay a while back. I don't remember the specific vendor but it was similar to this item:

http://www.ebay.com/itm/NEW-7-Mini-Netb ... 3cbb713d02

And I'm not advocating buying one. They are too slow.... But I bought one so I thought I might as well use it for some experimenting....

To cross compile, you need to install cross compile tools. I used ELDK 5.0 but there are a number of them that should work. Add the cross compile tool bin directory to your $PATH and then in the top of your kernel source directory do:

make mrproper
make copy the config file as the file ".config"
make ARCH=arm oldconfig
if you want to change any of the config settings, do: 'make ARCH=arm menuconfig'
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi-

[asiekierka]

For those of you who don't want to bother, have a precompiled 3.0.0 kernel. Put it in the FAT partition, put the Arch Linux .tar.gz in the EXT partition, and it should just work out of the box.

http://code.google.com/p/yus-repo/downloads/detail?name=wm8505-kernel-3.0-fatpart.tar.gz&can=2&q=

[wkt]

With the yus 3.0.0 kernel above the arch linux now boots on my wm8505 netbook.
I made the changes/additions described above in the /etc/fstab file.

Kernel compilation is just now toooooo hard for me - I am no(t yet a) system expert.

But as an advanced user I now installed with pacman the xfce4 group/package
( and also xorg-server ). But startxfce4 does report errors.
It says that "no screens" are found and "fbcon" module is missing (?).

So I think I have the usual problem with xorg.conf (?). I tried also the version on my Debian
system running on wm8505 but this didnt help either.

Also I know about the fbcon.ko module which is available in the Debian distribution
deep down under /lib/modules/kernel......... But this kernel is something like 2.6.29
I already had problems with its modules on yus 3.0.0 when it reported an invalid format
of the module(s) ( WiFi e.g. )

Any help in this situation ?

[wkt]

I got xfce4 to run : simply had to install

pacman -Sy xf86-video-fbdev xdbr sudo

Now I can at least run with the 3.0.0-yus kernel and also use LAN internet.
No idea how WiFi could work though.

I also made some tests with kernel compilation but fail with a dark/blank screen
when I boot the compiled kernel.
The kernel which I downloaded is of version 2.6.37.3. But I dont know how I get
the matching modules... There are also remarks in the net that kernels perhaps
cant read the root filesystem from SD ( only from USB ) ???
If I run make modules_install I get an error message which says that in
/usr/lib/modules the 2.6.37.3 dir is missing.

Any hint what to do ?

[wkt]

A short remark on the WiFi :

I put a LogiLink USB WiFi stick ( WL0049A, Made in China ) into the
USB port and had the wicd Network Manager installed.

This way WiFi works ( have a tested wpa_supplicant.conf file
and ran wpa_supplicant... )