[U-Boot-Users] Flash vs DataFlash vs NAND Flash

[Jerry Van Baren <gerald.vanbaren@smiths-aerospace.com>]

Matt Gessner wrote:
> Hi, all,
> 
> On my AT91RM9200 board, I have an Atmel DataFlash for booting off my
> SPI, and I have a NAND flash.
> 
> I do not, however, have any other kind of flash.
> 
> My 128K DataFlash address is 0xc0000000, and my 128MB of RAM is at
> 0x20000000.
> 
> When I do 
> 
> 	cp.b 20200000 c0000000 2c60
> 
> 	Copy to DataFlash... done
> 
> it works just fine.
> 
> When I do
> 
> 	cp.b c0000000 20200000 2c60
> 
> the system crashes with a data abort, but before the crash, it reports
> 
> 	Copy to Flash...
> 
> Well, I'm quite confused how to set the various flash flags to make all
> this work.
> 
> If I try to set CFG_NO_FLASH, the system won't compile.
> 
> But there is no "conventional" flash on the board... just the nand
> (8-bit port) and dataflash (spi).  
> 
> Would someone kindly point me to a reference that explains how I can set
> up u-boot 1.2.0 to make this work?  Or just come straight out and tell
> me?
> 
> Thanks in advance,
> 
> Regards,
> 
> Matt Gessner

 From the last message before the crash, it looks like you have 
non-existent "flash" configured in the memory space where your RAM 
resides, so the second cp.b tries to do the NOR flash "song & dance" to 
"unlock" it.  Of course, this writes trash into your SDRAM which crashes 
your program.

1) Find where NOR flash in configured for your board/cpu/system and
      fix it.
2) Figure out why CFG_NO_FLASH causes your compile to break.  You
      apparently have an inadvertent dependency, or NAND flash requires
      it (I don't have any experience with NAND flash or ARM(r)
      processors)

Fixing #1 may fix #2.  Finding #2 may point to where #1 is broken.

HTH,
gvb