On 08/12/2011 08:31 AM, Werner Almesberger wrote: > Xiangfu Liu wrote: >> I met once yesterday: >> http://en.qi-hardware.com/irclogs/latest.log.html#t10:07
the correct link is http://en.qi-hardware.com/irclogs/qi-hardware_2011-08-11.log.html#t09:42 >> ~~~~ >> xiangfu I tried 7 times then it can not boot up. then I use jtag read >> the standby back. >> xiangfu diff with origin one. I got one diff: >> xiangfu -0000a80 0000 26cc 0000 0000 0000 0000 440c 6000 >> xiangfu +0000a80 1000 26cc 0000 0000 0000 0000 440c 6000 >> ~~~~ > > It would be good to read back several times, because USB-JTAG may > itself introduce (hopefully random) errors. Hi Werner I miss the chance. :( > > Michael Walle mentioned on #milkymist that reading the NOR via gdb > (using the serial port of the USB-JTAG board) would be much faster > than with JTAG. And in addition, gdb protects the data with its own > checksum, which may help. > Hi Michael Walle how to do that, can you give me some tips > In any case, this is useful information: > > - the problem does seem to be persistent. I.e., if you reset (?), > it doesn't disappear it persistent, I tried up-plug several times, cann't boot anymore > > - if this was indeed a "0" -> "1" bit flip, that's worrying. The > NOR is erased to "1" and a write changes a "1" into a "0", but > cannot change "0" back to "1". sorry. not clear about this. the origin is '1', it changed from '1' --> '0' > > Did the boot failure occur immediately after flashing, or did the > board boot normally for a while before starting to fail ? I am try to [power cycle] --> [rending 30 seconds] --> [power cycle] in my m1 it failure at 7 times. > > What we still don't know is whether this what you observed on > M1rc2 is truly same problem that Adam sees on M1rc3. But I guess > we'll find out soon enough :-) > >> then I only reflash the standby. test ~18 times. all works fine. > > If this is really a NOR corruption and if it is caused by incorrect > sequencing of power supplies, perhaps power-cycling (instead of the > reset button) could make it happen more often. > > - Werner _______________________________________________ http://lists.milkymist.org/listinfo.cgi/devel-milkymist.org IRC: #milkymist@Freenode Twitter: www.twitter.com/milkymistvj Ideas? http://milkymist.uservoice.com
