[U-Boot] U-Boot X86 bootstart

[Graeme Russ]

Hi Ondrej Kupka

On 30/09/11 21:06, Ondra Kupka wrote:
> Hello,
> 
> I've been digging a bit in X86 bootstart asm code and found possibly wrong
> code, as far as I understand:
> 
> In u-boot/arch/x86/cpu/start.S, there is piece of code to disable caches:
>     
>     /* Turn of cache (this might require a 486-class CPU) */ 
>     movl    %cr0, %eax
>     orl     $(X86_CR0_NW | X86_CR0_CD), %eax
>     movl    %eax, %cr0
>     wbinvd
> 
> , which perfectly makes sense to me. What doesn't really make sense then is:
>  
>     /* Turn of cache (this might require a 486-class CPU) */
>     movl    %cr0, %eax
>     orl     $(X86_CR0_NW & X86_CR0_CD), %eax    - AND HERE???
>     movl    %eax, %cr0
>     wbinvd
> 
> in start16.S of the same directory.
> 
> Is is wrong or not?

Nice catch :) At least one of them is wrong - I'll sort out a patch (unless
you want to submit a patch yourself that is)

> 
> Thanks a lot,
> Ondrej Kupka

Thank you

Regards,

Graeme