How can I install Digi Embedded Linux to SD card on a CCWi-i.MX53 kit?

Question

Hello,

I have a CCWi-i.MX53 kit.
Its flash is preloaded win WinCE OS.
There are jumpers to select boot device. I.E. it should be possible to have another OS on SD card, microSD card and boot it instead of using onboard flash.
I saw 3 variants of my kit : 1 for android, 1 for WinCE (the one I have) and 1 for Digi Embedded Linux (DEL Linux).

Question is :
Where do I find a binary image of a DEL Linux to direct copy to SD card? Or any other wys to get this DEL Linux working from SD card without overwriting the preloaded Win CE ?

Thanks.

Answer 1

to boot module from kernel stored in fat32 partition on sd-card you should do from u-boot:
dboot linux mmc 0 fat
dboot linux mmc 1 fat

one for SD one for uSD
The second partition should be EXT3 and contain your rootfs files (extracted, not image)

this document talks about how to boot android from sd card, but android is based on Linux so you can figure it out:
booting android from SD card

if you have installed DEL you'd have images in /usr/local/DigiEL-5.9/images/ccwmx53js/ folder

The easiest way to boot your board without touching FLASH is to boot from tftp/NFS ("dboot linux tftp" command from u-boot)

you can also partition your FLASH to have both Linux and CE images at the same time and boot either one with a key press is you set u-boot environment variables:
key1=dboot linux flash
key2=dboot wce flash

Answer 2

Thanks LeonidM.

I'm not a Linux specialist, but what I could understand is (if I want to boot DEL from a SD card) :

-I should partition a SD with FAT 16 as 1st partition, and ext3 as the 2nd.
-The FAT16 partition should have the Linux kernel file.
-The ext3 partition should have the Linux filesystem (extracted).
Am I right ?

Problem is : where do I find these kernel file and filesystem ton extract ?

As you mentionned, I found images in DEL :
/usr/local/DigiEL-5.9/images/ccwmx53js/
files are :
rootfs-ccwmx53js-128.jffs2
rootfs-ccwmx53js-512.jffs2
rootfs-ccwmx53js.initrd
u-boot-ccwmx53js.bin
u-boot-ccwmx53js_128sdram.bin
u-boot-ccwmx53js_ext_eth.bin
uImage-ccwmx53js

Is the kernel file here ? And the filesystem to extract ?

With the SD correctly created, then booting from u-boot with dboot commands should be ok.

I could also boot from TFTP, as you mention it's easier, but I have no idea how to do it and I prefer a local OS for booting as I'm going to use this board with my students for experiments.

Thanks for the help!

Comments

uImage-ccwmx53js is the Linux kernel image

To get the root file system files for ext3, build a project with root file system and you will find the files in $(WORKSPACE)/$(PROJECTDIR)/build/rootfs

Another option is to extract files from the .jffs2 image file:
$ mknod /tmp/mtdblock0 b 31 0
$ modprobe mtdblock
$ modprobe mtdram total_size=65536 erase_size=256 / or total_size=16384 erase_size=512
$ modprobe jffs2
$ dd if=/pathtoimage/rootfs.jffs2 of=/tmp/mtdblock0
$ mkdir /media/jffs2
$ mount -t jffs2 /tmp/mtdblock0 /media/jffs2
$ find /media/jffs2 -ls

for next file:
$ umount /media/jffs2
$ modprobe -r mtdram
that continue with $ modprobe mtdram .. like above

you probably need to have installed packages:
$ apt-get install mtd-tools
$ apt-get install mtd-utils

all commands above need to be executed as ROOT!!!

see: http://aneeska.com/2010/01/07/how-to-mount-a-jffs2-image/