[U-Boot-Users] Strange : Same 8248 image needs to be reprogrammed

Sam Song samsongshu at yahoo.com.cn
Mon Jun 27 09:07:24 CEST 2005

Jerry Van Baren wrote:
> >>Pull up RSTCONF -> Connect WireTAP with No-head 
> >>config file -> Program the image on 0xff000000
> >>-> Disconnect WireTAP -> Pull down RSTCONF 
> >>-> Power-on -> No serial output -> Power-down
> >>-> Connect WireTAP with head config file 
> >>-> Reprogram the same image at 0xff000000 
> >>-> Disconnect WireTAP -> Power-on -> Work!
> The reason your first approach didn't work is
> because the HRCW gets read from the 
> _first_32_bytes_ of flash (four reads at offsets 0, 

In my first programming, RSTCONF pull up, HRCW is the
default vaule 0x00000000. It doesn't need to read it
from FLASH at all.

> 8, 16, 24 with CS0 asserted).  It isn't read from 
> any true "address" - BR0/OR0 are configured by the 
> HRCW and thus cannot be used for reading the HRCW.

Yeah, I do agree. In 

> When you programmed u-boot at 0xFFF00000, u-boot was
> programmed into the proper location but the HRCW

I didn't program u-boot on 0xFFF00000 in this case.
0xFF000000 instead.

> This is another reason for doing "low-boot" rather
> than "high-boot": in
> "low-boot" mode, both u-boot and the HRCW get placed
> in the proper memory locations inherently.

Yeah, thanks to the perfect adjustment on 8260, all
we can do is to program one image at the first sector
of FLASH to finish HRCW and boot the target at the
same time. Low boot is much better than high boot
on this point.

> Answering your second question, my experience is
> that RSTCONF is necessary and _barely_ sufficient

So you mean RSTCONF MUST pull up when programming a
blank FLASH on a 8260 target with BDI?

> to program the HRCW in the first 32
> bytes of flash.  I never try to do more than that. 

So for every brand-new target, we need to pullup
RSTCONF once for programming the HRCW. Right?

Could we program the low-boot image at this time
once for all on BDI?

> Once you have a valid HRCW programmed, deassert 
> RSTCONF, cycle power (IMPORTANT since
> the HRCW is only read on a full reset) and proceed
> normally.

Uh, Does "proceed normally" here mean we can use BDI
to program the low-boot image at the first sector of 
FLASH? If so, BDI also needs to reprogram the low-boot
image at the first sector of FLASH.

Or "proceed normally"  means the programmed target 
can boot directly with the image which was done by
pull-up case?

Thanks a lot for your notes,




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