[fedora-arm] Flash GuruPlug NAND without JTAG cable?

[Joe McManus]

Hey Jon - If you do figure it out, please add it to the wiki. I am 
waiting for a JTAG myself, didn't notice the Guruplug did not have the 
serial built in.

Cheers,
-Joe


On Tue, 11 May 2010, Jon Hermansen wrote:

> Itamar,
>  I have read over many guides, including the Fedora wiki, Ubuntu
> ARM-specific wiki pages, plugcomputer.org, and a few other places but yet
> have not found what I've been looking for. All the pages I've read
> specifically refer to accessing U-Boot over serial (using the $40 box from
> Global Scale, or I can DIY) from another PC, and I can't do this at the
> moment. Specifically, I think the problem boils down to knowing specific
> offsets to data on the NAND on my GuruPlug board.
> 
> There are existing tools that will supposedly do what I want -- flash
> onboard NAND:
>  1. mtd-utils: http://www.linux-mtd.infradead.org/
>  2. sheeva-uboot-tools: http://code.google.com/p/sheeva-uboot-tools/
> 
> I assume that the latter tool relies on the former. Now, fw_printenv (part
> of mtd-utils) always throws "bad CRC" at me because I haven't figured out
> the correct offsets/sizes yet. I've done a nanddump on the partitions of the
> MTD that have the interesting bits on them, namely, the u-boot loader and
> the kernel. There is a third partition, that holds the rootfs:
>
>       [root at guru ~]# cat /proc/mtd
>       dev:    size   erasesize  name
>       mtd0: 00100000 00020000 "u-boot"
>       mtd1: 00400000 00020000 "uImage"
>       mtd2: 1fb00000 00020000 "root"
> 
> 
> I looked at the uImage bit in a hex editor, and found nothing interesting or
> configurable, just kernel junk. In the "u-boot" partition, I have found bits
> that look like configuration information, but I _do not_ want to modify the
> default u-boot options, in fact, I'd rather leave them in case I get a JTAG
> cable later or do something to bork my OS. I also can't discern where in
> this file lie the custom settings vs. the default settings, so I won't
> change any bits here yet...
> 
> I have considered another alternative, that is, only flashing over the
> uImage and rootfs MTD partitions. This would be fine, assuming that the
> shipped version of U-Boot does not limit functionality on my system... and I
> think this would allow me to install Fedora 12.
> 
> An additional alternative would be to fake passed parameters to the kernel,
> i.e. hack the kernel source to default to "root=/dev/sda" and thus
> overriding my current /proc/cmdline:
>
>       [root at guru ~]# cat /proc/cmdline
>       console=ttyS0,115200 ubi.mtd=2 root=ubi0:rootfs rootfstype=ubifs
> 
> 
> If anyone has any more information, please advise. I am considering writing
> to Global Scale / the kernel developers over at Marvell to see if they can
> drop me any hints...
> 
> On Sun, May 9, 2010 at 9:30 PM, Itamar Reis Peixoto
> <itamar at ispbrasil.com.br> wrote:
> On Sun, May 9, 2010 at 3:46 AM, Jon Hermansen
> <jon.hermansen at gmail.com> wrote:
> > Hello all,
> >  I just got a brand new GuruPlug a few days ago and I was hoping to
> install
> > Fedora ARM on it as soon as possible. Well, the only problem is, I
> neglected
> > to get the JTAG breakout box / cables required to get the U-Boot
> prompt and
> > thus, as far as I can tell, can't do much about loading a new U-Boot
> version
> > (hopefully to boot from microSD), putting a new U-Boot config, Linux
> kernel
> > and accompanying rootfs on the NAND/external MicroSD card. I can see
> the
> > /dev/mtd* devices from Debian 5.0.3, kernel 2.6.32-00007-g56678ec,
> but I
> > have yet to write to them from my live system as I want to be
> absolutely
> > sure about what I'm doing on this front.
> >
> > I'd also like to know if I can use the internal NAND/external
> MicroSD card
> > as one big device, as opposed to two seperate devices. I realize the
> NAND is
> > not addressed as a block device, but if they both can contain
> filesystems,
> > does that mean that I can use UnionFS (or something similiar) to
> bridge two
> > seperate filesystems and divide the space taken up by data between
> the two
> > storage devices?
> >
> > If anyone could provide any more information on what I'm attempting
> to do
> > (flash NAND, reinstall OS) without a JTAG cable, either on a
> SheevaPlug or a
> > GuruPlug (from what I've read, they are nearly the same), it would
> be
> > greatly appreciated.
> >
> > Thanks to all of you guys for working out the kinks in Fedora ARM,
> and I'm
> > looking forward to using my favorite distro on the smallest PC I've
> ever
> > had...
> >
> > Jon Hermansen
> >
> start here -> https://fedoraproject.org/wiki/Architectures/ARM
> 
> 
> --
> ------------
> 
> Itamar Reis Peixoto
> 
> 
> 
>