Re: [U-Boot] [PATCH 11/39] x86: Invalidate TLB as early as possible

On 6 November 2014 20:49, Bin Meng bmeng.cn@gmail.com wrote:

On Fri, Nov 7, 2014 at 4:20 AM, Simon Glass sjg@chromium.org wrote:

...

We should invalidate the TLB right at the start to ensure that we don't get false address translations even though paging is disabled.

Signed-off-by: Simon Glass sjg@chromium.org

arch/x86/cpu/start16.S | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/arch/x86/cpu/start16.S b/arch/x86/cpu/start16.S index e718d4b..445d5a1 100644 --- a/arch/x86/cpu/start16.S +++ b/arch/x86/cpu/start16.S @@ -24,6 +24,9 @@ start16: /* Set the Cold Boot / Hard Reset flag */ movl $GD_FLG_COLD_BOOT, %ebx

•   xorl    %eax, %eax
  

•   movl    %eax, %cr3    /* Invalidate TLB */
  

•   /* Turn off cache (this might require a 486-class CPU) */
    movl    %cr0, %eax
    orl     $(X86_CR0_NW | X86_CR0_CD), %eax
  

--

Reviewed-by: Bin Meng bmeng.cn@gmail.com

Applied to u-boot-x86.