[U-Boot-Users] Need help booting linux on 8265 eval board

Wolfgang Denk wd at denx.de
Mon Apr 19 12:25:55 CEST 2004

In message <BAY2-F118ipEC1GEuqu00001cde at hotmail.com> you wrote:
>   thanks for your reply.  I think i should describe the problem clearly.


>   First i explain why i modified the uboot/linux default values. I'm a 
> graduate student. the board is designed by my schoolfellow(the board use 
> 8265,but it is very like the board MPC8266ADS-PCI-AI), but this board is 
> not supported by uboot, I must modify the configuration of sdram,IMMR and 
> some other registers(from motorola datasheet). now the uboot looks running 
> well(it can read/write flash/sdram, scc and fcc is also working), but when 
> i boot the linux kernel, i meet the problem. i think  i must let 
> imap_addr(linux kernel)=IMMR(uboot), so I modify some default values.

Correct. But when you change somethiung, you better  understand  what
you change, and why, and how.

You must not try mapping the IMMR at such a low address. See
for some description about the Linux kernel's memory map.

>  Now I want to know why linux mapped at 0xC0000000 , the uboot say   "## 
> Transferring control to Linux (at address 00000000) ...", so KERNELLOAD 
> should be 0xc0000000 or 0x00000000? 

Don;t even think of changing KERNELLOAD or things  like  that  unless
you really understand what's going on. Both 0x00000000 and 0xc0000000
are  correct  addresses  -  one  being  a  physical  one, the other a
vrirtual one.

>     and if I use linux kernel 2.4.20,  CONFIG_CLOCKS_IN_MHZ should be 0 or 
> 1?

Neither 0 nor 1. It must be undefined.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
Minds are like parachutes - they only function when open.

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