Re: [edk2-devel] [PATCH V2] UefiCpuPkg/CpuDxe: Fix boot error

["James Bottomley" <jejb@linux.ibm.com>]

On Thu, 2021-01-07 at 12:56 +0100, Laszlo Ersek wrote:
> Adding James, Mike, and Tom:
> 
> On 01/07/21 04:10, Guo Dong wrote:
> > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3084
> > 
> > When DXE drivers are dispatched above 4GB memory in 64bit
> > mode, the address setCodeSelectorLongJump in stack will
> > be override by parameter. Jump to Qword is not supported
> > by some processors. So use "o64 retf" instead.
> > 
> > Signed-off-by: Guo Dong <guo.dong@intel.com>
> > ---
> >  UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm | 8 +++-----
> >  1 file changed, 3 insertions(+), 5 deletions(-)
> > 
> > diff --git a/UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm
> > b/UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm
> > index c3489bcc3e..a8216cd56f 100644
> > --- a/UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm
> > +++ b/UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm
> > @@ -20,13 +20,11 @@
> >  ;-----------------------------------------------------------------
> > -------------
> >  global ASM_PFX(SetCodeSelector)
> >  ASM_PFX(SetCodeSelector):
> > -    sub     rsp, 0x10
> > +    push    rcx,
> >      lea     rax, [setCodeSelectorLongJump]
> > -    mov     [rsp], rax
> > -    mov     [rsp+4], cx
> > -    jmp     dword far [rsp]
> > +    push    rax
> > +    o64 retf
> >  setCodeSelectorLongJump:
> > -    add     rsp, 0x10
> >      ret
> >  
> >  ;-----------------------------------------------------------------
> > -------------
> > 
> 
> I'm asking for:
> James Bottomley <jejb@linux.ibm.com>
> - a Reviewed-by or Tested-by from James please, and

Tested-by: James Bottomley <jejb@linux.ibm.com>

James