[U-Boot-Users] AT91 with framebuffer in SDRAM

[Ulf Samuelsson]

> Hi,
>
> I'm trying to cobble together a proto with the AT91SAM9261EK and a WVGA 
> TFT
> screen using Ulf's 1.2.0-atmel branch. I have gotten the screen to work 
> just
> fine. The problem is that I need to operate out of SDRAM, and I'm trashing
> the environment variables somehow. The environment variables are at
> PHYS_SDRAM + 0x100 and are 0x2000 long so I have tried PHYS_SDRAM + 
> several
> larger numbers (0x10000, 0x20000, 0x100000) for fb_base but all result in
> corrupt environment variables when I try to save them. I believe that I am
> staying out of u-boot's operating RAM (0x23f00000+ correct?), but I could 
> be
> mistaken.
>

The environment variables should be stored in flash, not in SDRAM.
- Even if you execute from SDRAM.

What type of flash are you using.
My stuff is there to support dataflash, and anything else
get little or no testing.

> The symptom is the constantly-recurring bad CRC warning and saveenv 
> appears
> to have no effect. The settings seem to be working fine when I switch
> fb_base back to AT91C_IRAM, but obviously the display doesn't function
> properly. I've looked through for obvious mistakes in writing the logo and
> text below the logo to the fb but haven't been able to track anything 
> down.
>
> Also, as an aside, I think that the vl_pixclock variable is used 
> incorrectly
> in the at91sam926X files. It is supposed to be (from the definition) in
> picoseconds but appears to only work in Hz.
>
> Any help is appreciated.
>
> Thanks,
> Zac
>


Best Regards
Ulf Samuelsson