Atmel AT91SAM9G20-EK can't boot ArchLinuxARM-armv5te-latest

[larrybaker]

I have a Glomation GESBC-9G20 (http://www.glomationinc.com), which is essentially an Atmel AT91SAM9G20-EK (it uses the AT91SAM9G20-EK default Kernel config and AT91SAM9G20-EK U-Boot). I have Glomation's Linux 3.2.6 kernel and the config file they used. Their kernel includes support for EABI. I have also updated to the latest Atmel AT91 bootloader and U-Boot 2013.07.

I am not able to boot using the Arch Linux ARM V5TE rootfs, ArchLinuxARM-armv5te-latest.tar.gz.

There was a thread with questions about a similar board titled "Atmel AT91SAM9G20 - Linux kernel 2.6.31 & Busybox 1.15", viewtopic.php?f=9&t=2491&p=13887&hilit=atmel#p13887. One of the responses made it sound like it should be relatively easy to run Arch Linux ARM with a vendor kernel:

$this->bbcode_second_pass_quote('', 'I')t looks like CPU in the SoC is an armv5 (ARM926EJ-S specifically) and there are sources for newer kernels out there. We ought to be able to run on it, if you bring your own kernel.

[moonman]

Check your kernel bootparams in U-Boot

$this->bbcode_second_pass_quote('', 'F')ailed to mount /dev

[larrybaker]

moonman,

The kernel bootargs are exactly the same for any USB stick rootfs. I have no trouble with the vendor's Debian squeeze rootfs.

See, for example, my post #5 at http://glomation.net/smf/index.php/topic,1382.0.html. From what I posted there, I think the rootfs mount has already succeeded when the "Failed to mount /dev" message occurs. (I'll double check for you when I get home -- that is where I am doing this development. I didn't cut and paste very many lines when I posted there.)

[moonman]

well then it must be in the kernel config. ArchLinux uses systemd, not sys V init so it needs these enabled:

REQUIREMENTS:
Linux kernel >= 3.0
CONFIG_DEVTMPFS
CONFIG_CGROUPS (it's OK to disable all controllers)
CONFIG_INOTIFY_USER
CONFIG_SIGNALFD
CONFIG_TIMERFD
CONFIG_EPOLL
CONFIG_NET
CONFIG_SYSFS

Reference: http://cgit.freedesktop.org/systemd/systemd/tree/README

[larrybaker]

moonman,

That is precisely the sort of advice I'm looking for. I will see how the Glomation config file defines those.

Thank you.

[larrybaker]

moonman,

Adding kernel support for systemd fixed the problem. Thank you for providing the README reference; they had more listed there, some of which I felt safe in ignoring by following what I found in the Arch Linux ARM Kirkwood kernel config file. I still have more experimenting to do with the kernel options as I compare what Arch Linux ARM uses to what I have.

My next problem is to build an Arch Linux ARM rootfs that will will fit in the 256MB flash on the GESBC-9G20. Are there tools to build a tailored rootfs for Arch Linux ARM? Anything like Red Hat's installer that lets me build a bare "Minimal" system? Or, like uClinux's pick-and-choose menus?

Thank you.

[moonman]

There isn't really an easy way afaik. I would start with removing what you don't need (like headers) disable logs or move them to tmpfs and limit their size.

[larrybaker]

It's likely I'll abandon my efforts to run Arch Linux ARM on my board. I am able to run the latest armv5te rootfs off a USB stick, but I had to add a swap file because the board only has 64 MB RAM. Using that, I set up a second USB stick using pacstrap base and just a couple other packages I need. It uses over 400 MB. My flash is only 256 MB. I could try to use compression with a UBIFS rootfs. But, realistically, that is not enough space for my application's data needs. Not to mention all the cycles it will take from my poor 400 MHz CPU (200 bogoMIPS) to read/write the flash. (There is really no good reason why Arch Linux should pile on so much stuff in the base group -- like reiserfs tools. I guess their target is not small systems.) I'll probably try something with BusyBox. I am open to other suggestions.

Thanks to all for your help.

[WarheadsSE]

You could pacstrap base, then remove what you don't need. 'base' is just a package group.