AW: [U-Boot-Users] USB booting...

[Martin Krause]

Hi all,

u-boot-users-admin at lists.sourceforge.net wrote on :
> In message <1120664027.6064.99.camel at daroca> you wrote:
> > I am attempting to boot Linux on a target platform using a
> > USB mass storage device (flash disk) to hold the kernel and the
> > root filesystem.
> > 
> > I thought it may be a good idea to replicate the same steps
> > used when booting from a tftp server, i.e. I copy the root
> > filesystem (using an initrd image) to an address in RAM, then
> > copy the kernel to a different address in RAM.  Finally bootm with
> > the start address of the kernel. Bootargs will be set during this
> > process.
> 
> You can do it this way, but it is a waste of system  RAM.  Why  don't
> you use a (read-only) file system mounted on the USB device?

I tried this with a read-only ext2 root file system on a linux partition
on an USB memory stick some time ago - and failed. I hadn't much time
to analyze what's going wrong but I think the problem was that the
kernel (linuxppc_2_4_devel from denx) tried to mount the root file 
system _before_ initializing of the usb sub system has completed. At
least the console messages looked so - but perhaps I missed something.

Has anybody else tried this? I would be happy to hear about a 
successful way to do this.

Regards,
Martin