| Message ID | 20200108110844.5655-1-masahiroy@kernel.org |
|---|---|
| State | Accepted |
| Commit | 0d67fac29f3187e67f4fd3ef15f73e91be2fad12 |
| Headers | show |
| Series | x86: use invd instead of wbinvd in real mode start code | expand |
On Wed, 8 Jan 2020 at 04:09, Masahiro Yamada <masahiroy at kernel.org> wrote: > > I do not know why the boot code immediately after the system reset > should write-back the cache content. I think the cache invalidation > should be enough. > > I tested this commit with qemu-x86_defconfig, and it worked for me. > > Signed-off-by: Masahiro Yamada <masahiroy at kernel.org> > --- > > arch/x86/cpu/start.S | 2 +- > arch/x86/cpu/start16.S | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) Reviewed-by: Simon Glass <sjg at chromium.org>
diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S index 01524635e9c8..26cf995db2d0 100644 --- a/arch/x86/cpu/start.S +++ b/arch/x86/cpu/start.S @@ -50,7 +50,7 @@ _x86boot_start: movl %cr0, %eax orl $(X86_CR0_NW | X86_CR0_CD), %eax movl %eax, %cr0 - wbinvd + invd /* * Zero the BIST (Built-In Self Test) value since we don't have it. diff --git a/arch/x86/cpu/start16.S b/arch/x86/cpu/start16.S index 54f4ff6662a8..292e75050814 100644 --- a/arch/x86/cpu/start16.S +++ b/arch/x86/cpu/start16.S @@ -28,7 +28,7 @@ start16: movl %cr0, %eax orl $(X86_CR0_NW | X86_CR0_CD), %eax movl %eax, %cr0 - wbinvd + invd /* load the temporary Global Descriptor Table */ data32 cs lidt idt_ptr
I do not know why the boot code immediately after the system reset should write-back the cache content. I think the cache invalidation should be enough. I tested this commit with qemu-x86_defconfig, and it worked for me. Signed-off-by: Masahiro Yamada <masahiroy at kernel.org> --- arch/x86/cpu/start.S | 2 +- arch/x86/cpu/start16.S | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)