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Return of the Shiva II

(this is just a fancy reminder for myself for the next time I trash my sheeva)

Upgrading the u-boot of the sheevaplug is super easy.

In the unlikely event that something goes wrong and you trashed the u-boot, so that the sheeva doesn't respond to anything anymore, don't panic! It's not to hard to flash u-boot again without a working instance on the device itself.

First of all, install openocd on whatever you have left working (e.g. your laptop), ensure that the usb cable is still well-connected and open three shells, one root (#) and two users ($).

$ screen /dev/ttyUSB0 115200

# openocd -f /usr/share/openocd/scripts/board/sheevaplug.cfg

$ telnet localhost 4444
Connected to localhost.
Escape character is '^]'.
Open On-Chip Debugger
> sheevaplug_init
target state: halted
target halted in ARM state due to debug-request, current mode: Supervisor
cpsr: 0x000000d3 pc: 0xffff0000
MMU: disabled, D-Cache: disabled, I-Cache: disabled
> nand probe 0
NAND flash device 'NAND 512MiB 3.3V 8-bit (Hynix)' found
> nand erase 0 0x0 0xa0000
erased blocks 0 to 5 on NAND flash device #0 'NAND 512MiB 3.3V 8-bit'
> nand write 0 /tmp/u-boot.kwb 0 oob_softecc_kw
> resume

(especially the 'nand write' needs a bit of time and produces no output, so calm down, that's okay)

In the first shell with the tty connection we should see now our lovely u-boot again!

Watch out, for me on this try, u-boot claimed that my configuration was broken and used its default. Not a problem for me, i just redid what is described on the install page above: (I would have needed to anyway, as 'mmcinit' changed to 'mmc init')

>> setenv bootargs_console console=ttyS0,115200
>> setenv bootcmd_mmc 'mmc init; ext2load mmc 0:1 0x00800000 /uImage; ext2load mmc 0:1 0x01100000 /uInitrd'
>> setenv bootcmd 'setenv bootargs $(bootargs_console); run bootcmd_mmc; bootm 0x00800000 0x01100000; reset'
>> saveenv

'reset' is added by me to restart the sheeva in case the bootcmd failed. 'mmcinit' used to fail sometimes with the old u-boot, now it seems to be better, but you can never be sure…

So, relatively easy: Welcome back sheeva!

Let's see then I am able to trash it again…

Disclaimer: Yes, the upgrade description linked above is completely correct and should work flawless for everyone. Seems like I overlooked a 'FAT entry invalid' message or something like that so I flashed nothing to the place u-boot belongs to…

P.S.: New posts related to APT changes? Mhhh. Not too soon, but i will try…

Return of the Kindle

Amazons Kindle is a nice device. I can't say like others that my reading habit exploded, but as I am traveling a lot by train between hometown and university its quite useful to read a bit of university stuff on it, play a silly game or really reading a book. All in all it well worth the investment last year in Orlando, FL. Shipping and Taxes always kill the fun in buying something online if it's not sold in Germany…

Anyway, a week before Paris I had a problem: I planed reading "Ender's Game" as I thought the reservation-only train will be overcrowded so no space to "play" on my laptop - but my kindle only showed my screensaver and didn't reacted to anything. I noticed a one inch thick line in the middle of the device all across the screen and a few others just a few dots thick and high. What the hell? First my sheeva was fried and now a broken screen on my kindle.

Thankfully amazon saved my travel. After a lovely phone call (= none of "please hold the line", silly music, "have you tried"-questions after describing I already did that) the women on the other side of world and phoneline said "we will sent a replacement to …… I can't pronounce that!" 😄 Germany streets end most of the time with "straße" (which is our word for street). Please try to pronounce it now if you didn't even know the second last letter. 😛

It was sorted out and just a few days later well in time for Paris UPS handed me the package over. Incredible service! I am saying that now before even returning the broken one, so the process is not really over, but I am so fascinated that I had to say that now as I would be more than shocked now if something would go mad now…

Oh and for the record: I don't know why the screen broke in the first place: I had it lying around openly so in theory nothing which could have caused it – beside our cat maybe. She likes sitting on top of basically everything… but I have no prove, I am just trying to not give her an opportunity again. Tiger, I am watching you! 😉

(this post is backdated to fit better into the chronology)

Return of the Shiva

view into the power supply unit and how it spilt its contents all over the place
Image of the exploded PSU of my sheeva

Wikipedia says that shiva is the hindu deity known as the "Destroyer". Interesting that GlobalScale choose "sheeva" as the name for their first plug generation. Sounds a bit like a self-fulfilling prophecy… The internet is full of stories and images like the one on the left - "exploded" power supply units cause by… nobody knows for sure. It seems to be that attaching passive usb devices is not a good idea. My harddrive was self-powered but I had also a dvb-t card attached on a non-active usb hub… bad.

As a proper replacement PSU shipped by NewIT would be available only in late February I crafted a replacement together by myself from an unused ac/dc adapter as an external powersupply. I am always a bit scared by hardware-modding but stripping and connecting the wires was easy after finding descriptions like this so my sheeva raised from the death - lets see how long this will last. Next week I will properly shop for an active hub to decrease the PSU risk further. At some point I should also get a real replacement PSU, but at least I can wait and search now for one where the cost isn't doubled (or even more) by shipping costs… (Why is there no German based distributor, who has one available?)