Boot linux from cramfs on USB

[Jakob Malm]

Hi,

Thanks for your prompt reply!

Den 2 april 2012 16:29 skrev Sascha Hauer <s.hauer at pengutronix.de>:
> On Mon, Apr 02, 2012 at 03:58:49PM +0200, Jakob Malm wrote:
>> Hi,
>>
>> How would I boot a linux system in a cramfs image on USB? I don't seem
>> to be able to mount such an image:
>>
>> ...
>>
>> Is it not possible to mount a cramfs image file?
>
> cramfs currently has the limitation that it can only mount
> files which are memory mappable (that is for example nor flash).
> I never fixed this due to the lack of interest for cramfs.

Ok.

>
> That said, your setup seems a bit crazy. What is inside your cramfs? The
> kernel? You should rather put your kernel into a plain partition on the
> USB disk. Or do you only have your rootfs inside the cramfs? I rather
> recommend ext2 or ext3 for this.

The cramfs would contain the rootfs, including kernel.

I want to be able to have FAT on the disk, preferably with a single
file (possibly two), containing the kernel and rootfs, and then load
up the rootfs into memory and start the kernel with that rootfs. I
suppose I could create a command specific for our case, but it seems
like a common enough scenario to me that someone else should have done
something similar...

/Jakob