[U-Boot] Need Help in bulding U-boot-2010-06 for OpenRD client

[Prafulla Wadaskar]

> -----Original Message-----
> From: Albert ARIBAUD [mailto:albert.aribaud at free.fr] 
> Sent: Wednesday, July 07, 2010 4:38 PM
> To: Prafulla Wadaskar
> Cc: u-boot at lists.denx.de; kalyan karnati
> Subject: Re: [U-Boot] Need Help in bulding U-boot-2010-06 for 
> OpenRD client
> 
...snip...
> >> skips very early and critical initialization code -- and 
> without this
> >> code u-boot won't start from Flash (this config option is
> >> used precisely
> >> when running u-boot from RAM).
> >
> > On Kirkwood boards, best way is to create kwb target (i.e. 
> u-boot.kwb)
> > for details refer doc/README.kwbimage
> >
> > Regards..
> > Prafulla . .
> 
> Thanks Prafulla, this explains why flashing the u-boot file 
> won't work.
> 
> This also leads me to asking a question.
> 
> Apparently, some low-level inits are performed by the 
> kirkwood rom boot 
> code based on the DATA lines in the kwbimage.cfg file rather 
> than by the 
> u-boot low level inits (this explains why the board config files have 
> CONFIG_SKIP_LOWLEVEL_INIT yet would boot from NAND).
> 
> But I have another problem that may be caused by this kwbimage.cfg 
> approach: the u-boot image does not run in RAM when launched from the 

you should use u-boot.bin to load in RAM @ 0x600000 (TEXT_BASE)

> current (NAND-loaded) u-boot with tftp and go. Judging from 
> the README 
> you pointed to, the kirkwood u-boot code probably misses some 
> critical 
> inits, which the kwbimage.cfg adds to it.
> 
> Could it be that the low level init code for the kirkwood 
> always assumes 
> that all critical inits have already been performed when 
> u-boot starts, 
> and thus u-boot does not do them at all?

YES

> 
> Problem is, kwbimage.cfg has boot options for sata, spi and 
> nand but not 
> -- of course -- RAM, so I can't fix this 'running from RAM' 
> issue using 
> kwbimage.

This is not objective of kwbimage, kwbimage appends header to u-boot.bin which directly read by internal bootROM to achieve boot from supported medias on Kirkwood.

for boot from RAM, you must need at least SDRAM configured, so JTAG is the way

Regards..
Prafulla . .