[U-Boot-Users] minimum bdi config to read flash on 85xx
robert lazarski
robertlazarski at gmail.com
Fri Sep 14 22:05:35 CEST 2007
On 9/14/07, David Hawkins <dwh at ovro.caltech.edu> wrote:
> Hi Robert,
>
> > After a few days with the docs, we've had some limited success. We
> > moved back to 128MB of ram and a base address of F8000000 . We think
> > we may have some timimg issues. To read the manufactor id the docs
> > say:
> >
> > *( (UINT16 *)base_addr + 0x555 ) = 0x00AA; /* write unlock cycle 1 */
> > *( (UINT16 *)base_addr + 0x2AA ) = 0x0055; /* write unlock cycle 2 */
> > *( (UINT16 *)base_addr + 0x555 ) = 0x0090; /* write autoselect command */
> > manuf_id = *( (UINT16 *)base_addr + 0x000 ); /* read manuf. id */
> >
> > So in our case we start with LAD30, so we need to do a shift left:
> >
> > AAA = 555 << 1;
> > 554 = 2AA << 1;
>
> Do you really? I would have thought that the address code
> was a byte-address, and therefore invariant for this part.
> In 16-bit mode the device doesn't see the last bit.
> Double-check :)
>
OK guys, its working!!!! YEAH!!!! Last problem turned out to be an
open resistor / bad solder joint on the address bus! We can now erase
the flash chip entirely. I also did the prog command to upload
uboot.bin and can see the uboot version at the base address - so this
stage is now completed!!!! Thanks so much for all the help guys, I
doubt we would have gotten so far without this community and we are
most grateful! I feel so much smarter now ;-) .
Last question before I get into my code finally - and I'll start a new
thread when I start debugging: The bdi docs in the uboot manual seem
to stop at the 'go' command. When I type 'info' I get a running state.
Can I now just power on and attach a terminal via the serial port to
get the uboot shell? To get to that point is the next dragon to slay?
Thanks!!!
Robert
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