On 11/15/07, schardt g.schardt@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.