Re: [U-Boot] U-Boot X86 bootstart

On Friday, September 30, 2011 01:06:04 PM 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?

Thanks a lot, Ondrej Kupka

Ccing Graeme, cheers