[Arm-netbook] AllWinner F20/A10 - SDRAM initialisation

[Henrik Nordström]

sön 2012-06-03 klockan 16:52 +0200 skrev sysfwlab:
> Related to my porting project "uboot for sun3i",  i'm able to manager my 
> SDRAM now and it's a good thing but my sdram init procedure is not very 
> elegant. Can someone tell my if it's a common behavior to need to 
> read/write'n compare like 'brutus' to wait SDRAM be intialized ?

I don't think so.

sun4i certainly do not, instead it waits on status bits from the dram
controller at three stages. See dram_wait_init() and dram_read_pipe()
calls in
https://github.com/hno/uboot-allwinner/blob/sun4i/arch/arm/cpu/armv7/sunxi/dram.c 

You might want to peek into boot0 for your device to see how it's done
there. boot0 can be found both in the boot sectors of the NAND and in
firmware upgrade files.

> Do you think this way can destroy controller in future ?

Probbaly not.

Regards
Henrik