NOR flash, NAND flash and the steppingstone

[Wolfgang Draxinger]

Am Montag, 8. September 2008 schrieb Andy Green:
> Somebody in the thread at some point said:
> |> Well, that's about it. Did I get everything right?
> |
> | With the few exceptions above, yes. Good detective work :-)
>
> Just a little add to Werner, sequence of events about steppingstone
> is maybe easier to see from bootloader side looking at the new
> simpler Qi bootloader:
>
> http://git.openmoko.org/?p=qi.git;a=blob;f=src/start.S;h=1514e0f68a
>7c92eff27ef45c4f5c547c09106191;hb=HEAD
> http://git.openmoko.org/?p=qi.git;a=blob;f=src/start_qi.c;h=ac7d42e
>b57a41d742ee9874d27bff277ffad1ddd;hb=HEAD
>
> -Andy

You know, one of the first things I tried with the debug board, was to 
load the kernel image by JTAG. Since I didn't have setup code at hand 
I tried the following:

* let it boot into U-Boot
* halt it by JTAG
* upload the uImage.bin to 0x32000000
* resume execution
* send U-Boot the command "bootm 0x32000000"

Unfortunately U-Boot didn't like something about that, always giving 
me a CRC error.

Which brought me to the next idea: Write a tiny "just do the basic 
setup and prepare the kernel TAGs" stubcode, that would be uploaded 
to steppingstone and executed until breakpoint, so that JTAG can be 
used to upload the kernel into SDRAM, and then execution resumed in 
the kernel image with registers r0, r1, r2 pointing to the parameter 
structures.

And now I see, that such kind of project is already in work :-)

-- 
DraxIT - IT Services and Consulting
Voitstraße 10, D-80637 Munich
Tel: +49 89 18921108
Fax: +49 89 18921109
http://draxit.de