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

[Itamar Reis Peixoto]

On Tue, May 11, 2010 at 11:19 AM, Jon Hermansen <jon.hermansen at gmail.com> 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
>
>


you can access it using sheeva USB cable and gtkterm for example.





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Itamar Reis Peixoto