Nick and I have got somewhat further with the E1 build of loon 3s but
are still suffering some 2K-page-size-NAND-related problems. Summary of
discoveries:
- udelay was not implemented in bootldr for PXA so NAND access was
sometimes premature (before the NAND was really ready after a command).
This explained all the blocks getting marked bad and is now fixed and
checked in on the bootldr36-pxa-sa1100 branch. Reading NAND_RNB doesn't
yet work because it's not mapped to a register in the FPGA.
- checking out latest bootldr source from branch bootldr36-pxa-sa1100,
doing the mods for udelay and new FPGA, results in weird yaffs
behaviour: We can write a zImage in, but trying to boot it results in it
being detected as a BSD kernel image! Upon a reset all the files in
yaffs have disappeared.
- for comparison, we took an old version of the bootldr from SVN
(release 76, before the balloon2/3 to balloon rename took place) and did
the same mods. This works properly and yaffs doesn't misbehave. We
haven't yet figured out the difference.
- However, there remains some kernel oddness. The test-v0.1 kernel from
balloonboard.org grinds to a halt after initialising the serial ports
(it really does stop, not just change baud rate!). Trying a slightly
newer kernel and/or a 'known good' one from a random L3 dev board
results in most of the NAND getting reported as bad blocks. Nick thinks
this is a 2K page implementation issue in the kernel.
We are now declaring it the weekend and Nick is taking away an E1 board
to play with.
Chris
--
Chris Jones -
chris@martin-jones.com
Martin-Jones Technology Ltd, makers of Solidlights
148 Catharine Street, Cambridge, CB1 3AR, UK
Phone +44 (0) 1223 655611 Fax +44 (0) 870 112 3908
http://www.solidlights.co.uk/
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