[U-Boot] Facing problems in Porting U-boot to MIPS32 (Au1350)

[Andrew Dyer]

2010/4/23 Gurumurthy G M <Gurumurthy.Gowdar at gmobis.com>:
>
>
> let me know if anyone have ported u-boot to MIPS32.

I did a couple of ports for Au1550 boards back when it was still owned by AMD.

On Au1550 if the boot pins are set up for NOR flash, the CS0 line is
mapped with a base physical address 0x0_1fc0_0000 (36 bit physical
address) and a chip select mask of 0xf_fffc_0000 (range of 256K).
Without using the TLB (ie staying in KSEG1 virtual range), the top
physical address you can select is 0x0_1fff_ffff, so this is
effectively 4Mb down from the top of memory at boot time.

In lowlevel_init.S the base and range of the chip select can get
adjusted so that more of the flash is accessible by adjusting the base
address and mask.  As an example we had a board that adjusted to the
registers for a larger NOR mapped at 0x0_1f00_0000 with a size of
0x0_0100_0000.  Look in the dbau1550 port for more info.