Differences between revisions 7 and 8
Revision 7 as of 2010-08-30 18:54:48
Size: 2607
Editor: HolgerLevsen
Comment:
Revision 8 as of 2010-09-24 18:07:33
Size: 3230
Editor: ?VagrantCascadian
Comment: add uboot variables
Deletions are marked like this. Additions are marked like this.
Line 53: Line 53:
TBW ===== U-Boot =====

power on the device and hit space quickly to get to the uboot prompt. set some variables in uboot:

{{{
setenv bootdelay 10
setenv bootargs_base_nfs 'setenv bootargs console=ttymxc0,115200 console=tty1'
setenv nfs_boot 'run bootargs_base_nfs bootargs_nfs'
setenv boot_nfs 'run base_cmds;mmcinit;fatload mmc 0:1 ${loadaddr} ${kernel}; fatload mmc 0:1 0xa2000000 ${initramfs}; bootm ${loadaddr} 0xa2000000'
setenv bootargs_nfs 'setenv bootargs ${bootargs} root=/dev/nfs nfsroot=192.168.0.1:/opt/ltsp/armel console=ttyS0,115200 boot=nfs ip=dhcp ${bootinfo};run boot_nfs'
}}}

Summary

About

This page is about using ARM machines as diskless workstations (or more general, as LTSP clients).

At first, this page will only be about the Efika MX plattform, other hardware needs available hardware samples first. Contact me if you are able to help.

Status

In documentation phase (aka in development). In theory (and practice) Debian Edu is Debian, Debian supports ARM processors, LTSP is processor agnostic and Debian runs on the Efika MX. In practise, this shall be shown here.

Using the Efika MX as an LTSP client

Hardware

The Efika MX has current hardware specs, no movable parts, a case which is smaller than a DVD case (160x115x20mm) and is low on power-consumption: 4 Watts for the external power supply (when the device is powered off), 9 Watts for running idle and 11 Watts running under full (CPU) load. So it should be a pretty nice LTSP client :-)

Setting up an ARM LTSP chroot

Note: the following examples use Squeeze, which has not been released yet. So this shouldn't be used in production :-)

To be described here. There are two approaches: build it on an armel machine (like the Efika) or using qemu.

the QEMU approac

Using qemu-user-static on i386, cross-architecture building for armel is rather simple, the steps are:

# apt-get install qemu-user-static ltsp-server
# ltsp-build-client --arch armel

on the Efika MX

Requirements: a working Debian squeeze install, with the pre-installed OS you can use debootstrap to create one.

# apt-get install ltsp-server
# ltsp-build-client 

:-)

Network booting the Efika MX

The bootloader used on the Efika MX is called u-boot. Since the Efika MX uses the asix USB network interface and USB support in u-boot is rather new, and so it's broken for this piece of hardware. Future release of u-boot might fix this, but it's not clear if (or rather, how...) u-boot can be updated.

So the options available today are basically to load the kernel via SD card or the built-in flash, or load a kernel using kexec, which then downloads the real kernel and initramfs over the network and executes the new kernel. (And of course fixing u-boot or using another bootloader...) Per default the Efika MX boots from SD card if available, else from built-in flash.

Installing the LTSP kernel on a SD card

U-Boot

power on the device and hit space quickly to get to the uboot prompt. set some variables in uboot:

setenv bootdelay 10
setenv bootargs_base_nfs 'setenv bootargs console=ttymxc0,115200 console=tty1'
setenv nfs_boot 'run bootargs_base_nfs bootargs_nfs'                         
setenv boot_nfs 'run base_cmds;mmcinit;fatload mmc 0:1 ${loadaddr} ${kernel}; fatload mmc 0:1 0xa2000000 ${initramfs}; bootm ${loadaddr} 0xa2000000'
setenv bootargs_nfs 'setenv bootargs ${bootargs} root=/dev/nfs nfsroot=192.168.0.1:/opt/ltsp/armel console=ttyS0,115200 boot=nfs ip=dhcp ${bootinfo};run boot_nfs'

Installing the LTSP kernel on built-in flash

TBW