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