[U-Boot-Users] U-boot for Mips 4KEC

[Wolfgang Denk]

Dear Pooja,

in message <cmajjb$oie$1 at sea.gmane.org> you wrote:
> 
> In the process of porting U-boot for Malta which uses mips 4Kec I 
> discovered that the stack required for intial C environment can neither 
> be obtained by some on-chip memory (IMMR in MPC8xx ) nor by using DCACHE 
> in locked mode. Mips 4KC has the DCache locked mode support but Mips 
> 4KEC has it only through external pin interface.

I have o admit that I don't know the details of this  specirfic  CPU,
but are you _really_ sure that there is no way to lock (parts of) the
data cache? I would be relly suprised if this was the case...

> I am looking for a way of not using the C code till code has started 
> running from RAM. But how do I get the value of gd(global data pointer) 

This "way" is a major redesign and rewrite of U-Boot.

> which U-boot expects? README file does not mention anything about mips 
> registers which are specifially used for this purpose.

No matter what you do, sooner or later you will find  that  you  need
some  preliminary  stack  and  eventually  storage  space  for  a few
variables. So instead of creating several new problems,  I  recommend
to  try  to fix the root problem first, and all the rest will fall in
place.

Best regards,

Wolfgang Denk

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