I am struggling with this problem for a week now and not making any progress. So any suggestions, ideas or pointer will be greatly appreciated.
The board works with u-boot 1.3.2 and at91bootstrap(1.5 I only have the binary) booting from NAND. We have changes the SDRAM from 32bit databus to 16bit and NAND to 32M. I am using U-boot 1.3.2 and AT91bootStrap 1.8.
I changed the SDRAMC and PIOC init per Atmel's application notes in at91bootstrap.
U-boot fails intermittently at the start. When it fails, it didn't make it to my first printf statement. When I use JTAG to debug it, it always works.
If the board has been let without power for 1+ hour, it will also boot up when I apply power to it(something to do with the battery perhaps). Once it booted up,it is very stable. I can run Mtest etc.
We tried replacing NAND, SDRAM, etc. Along the way we are battling bugs with SAM-BA as well. We think that we have observed the same behavior on another board. We also experimented with different bootstraps and u-boot binaries.
The only thing we can think of is Reset cycle or some h/ware init code in u-boot that might not be compatible with at91bootstrap's init code.
We had at91bootstrap 1.5 working well in 32-bit mode with u-boot 1.3.2. But I don't have the source. I wonder what is the current stable version of u-boot and at91bootstrap?
Thanks in advance for your help.
Norman