-----Original Message----- From: Albert ARIBAUD [mailto:albert.aribaud@free.fr] Sent: Wednesday, July 07, 2010 7:36 PM To: Prafulla Wadaskar Cc: u-boot@lists.denx.de; kalyan karnati Subject: Re: [U-Boot] Need Help in bulding U-boot-2010-06 for OpenRD client
Le 07/07/2010 13:44, Prafulla Wadaskar a écrit :
you should use u-boot.bin to load in RAM @ 0x600000 (TEXT_BASE)
That's what I do, either through JTAG or by tftp/go in resident u-boot.
for boot from RAM, you must need at least SDRAM configured,
so JTAG is the way
JTAG does work indeed. Howvever, when:
- I power up the board;
- ROM boot loads u-boot from NAND and starts it;
- I stop u-boot and get to the prompt;
- I 'tftp' an u-boot.bin image into RAM at 1000000;
- I 'go' to 1000000
... the tftp'ed image fails to boot although SDRAM is obviously already configured.
This is obvious, since u-boot being copied is not created with TEXT BASE=0x100000, is it? And I don’t know how "go TEXT BASE" responds to u-boot binary itself, I have never tested this use case.
OTOH, openOCD boots the RAM image fine, so I guess OpenOCD does some inits that the boot rom plus resident u-boot don't.
Openocd configures RAM before loading u-boot.bin U-boot.kwb does the same but internal bootROM does this instead of openOCD in case of boot from NAND U-boot.bin anyway needs SDRAM configurations to be done by someone else before starting execution.
Regards.. Prafulla . .