[U-Boot-Users] Newbie, once again

[Grant Likely]

On 11/15/07, schardt <g.schardt at fz-juelich.de> wrote:
> Hi all,
>
> i'm still trying to run u-boot on the Xilinx4 FX12 MiniModul from Avnet.
> I think i'm on the wrong way....
>
> the powerpc in the xilinx4 has 32MB DRAM (mapped at 0x0000_0000 to
> 0x03ff_ffff) and  4MB Flash (mapped at 0x0600_0000 to 0x063f_ffff). the
> integrated 16k block-ram is at 0xffff_c000 to 0xffff_ffff).
>
> the last few days i tried to load the u-boot.srec image from flash into
> ram with the EDK srec-bootloader, and then run u-boot from ram. but this
> is not the right way, or ? The only output on the uartlite is :

If you were booting from the SystemACE and didn't have any memory
mapped SRAM, then using srec-bootloader, or some other first stage
bootloader to copy a u-boot image from a CF card to main DRAM.

However, in your case you do have memory mapped flash.  Use the
u-boot.bin image instead and burn it into flash.  Your first stage
bootloader (the one that runs out of block ram) only need to do one
thing; jump to the start address of u-boot in flash.

When u-boot starts executing, it will copy itself from FLASH to DRAM
and continue executing from there.

> -------- snipp -------------
> U-Boot 1.3.0-rc3 (Nov 15 2007 - 11:58:50)
>
> ### No HW ID - assuming ML300
> DRAM:  32 MB
> ------- snapp ------------
>
> What is the better configuration ?
>
> Locate the flash on 0x0000_0000 and the dram to some other location in
> den adress-space ? or work on with the old configuration ?

No!  Don't do this!  :-)

PowerPC Linux expects DRAM to be based at 0.  Flash can be mapped
anywhere as long as you have code at your boot vector that jumps into
it.

Cheers,
g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
grant.likely at secretlab.ca
(403) 399-0195