Re: [Patch 4/7] UefiCpuPkg: Update CpuExceptionHandlerLib pass XCODE5 tool chain

["Gao, Liming" <liming.gao@intel.com>]

Mike:
  Thanks for your comments. The style "mov     rax, strict qword 0" works. I will use it.

> -----Original Message-----
> From: Kinney, Michael D
> Sent: Thursday, January 11, 2018 5:58 AM
> To: Gao, Liming <liming.gao@intel.com>; edk2-devel@lists.01.org; Kinney, Michael D <michael.d.kinney@intel.com>
> Cc: Andrew Fish <afish@apple.com>; Yao, Jiewen <jiewen.yao@intel.com>; Dong, Eric <eric.dong@intel.com>; Laszlo Ersek
> <lersek@redhat.com>
> Subject: RE: [Patch 4/7] UefiCpuPkg: Update CpuExceptionHandlerLib pass XCODE5 tool chain
> 
> Liming,
> 
> Here is a previous patch email series that demonstrates
> this technique.
> 
> https://lists.01.org/pipermail/edk2-devel/2017-September/015109.html
> 
> https://github.com/tianocore/edk2/commit/4c34a8ea191155f438901e635bd87810072b19a4#diff-5d3b0f5982124c722c30f6d0e6b87
> 11d
> 
> Thanks,
> 
> Mike
> 
> > -----Original Message-----
> > From: Kinney, Michael D
> > Sent: Wednesday, January 10, 2018 11:22 AM
> > To: Gao, Liming <liming.gao@intel.com>; edk2-
> > devel@lists.01.org; Kinney, Michael D
> > <michael.d.kinney@intel.com>
> > Cc: Andrew Fish <afish@apple.com>; Yao, Jiewen
> > <jiewen.yao@intel.com>; Dong, Eric <eric.dong@intel.com>;
> > Laszlo Ersek <lersek@redhat.com>
> > Subject: RE: [Patch 4/7] UefiCpuPkg: Update
> > CpuExceptionHandlerLib pass XCODE5 tool chain
> >
> > Liming,
> >
> > Can we use NASM syntax for instructions instead of db
> > bytes?
> >
> > If you put the label for the fixup after the instruction,
> > you
> > can patch by subtracting the size of the patch value from
> > the
> > label.
> >
> > For example, instead of:
> >
> > > +    db      0x48, 0xB8
> > > +JmpAbsoluteAddress:
> > > +    dq      0 ;     mov     rax,
> > HookAfterStubHeaderEnd
> >
> > Use:
> >
> > 	movq	rax, 0
> > JmpAbsoluteAddress:
> >
> > And in the patch loop:
> >
> >     mov    qword [rcx + (JmpAbsoluteAddress - 8 -
> > HookAfterStubHeaderBegin)], rax
> >
> >
> > If this works, then please use this technique to remove
> > use of db for instructions throughout this series.
> >
> > Mike
> >
> > > -----Original Message-----
> > > From: Gao, Liming
> > > Sent: Wednesday, January 10, 2018 7:24 AM
> > > To: edk2-devel@lists.01.org
> > > Cc: Andrew Fish <afish@apple.com>; Yao, Jiewen
> > > <jiewen.yao@intel.com>; Dong, Eric
> > <eric.dong@intel.com>;
> > > Laszlo Ersek <lersek@redhat.com>; Kinney, Michael D
> > > <michael.d.kinney@intel.com>
> > > Subject: [Patch 4/7] UefiCpuPkg: Update
> > > CpuExceptionHandlerLib pass XCODE5 tool chain
> > >
> > > Use the dummy address as jmp destination, and add the
> > > logic to fix up
> > > the address to the absolute address at boot time.
> > >
> > > Contributed-under: TianoCore Contribution Agreement 1.1
> > > Signed-off-by: Liming Gao <liming.gao@intel.com>
> > > Cc: Andrew Fish <afish@apple.com>
> > > Cc: Jiewen Yao <jiewen.yao@intel.com>
> > > Cc: Eric Dong <eric.dong@intel.com>
> > > Cc: Laszlo Ersek <lersek@redhat.com>
> > > Cc: Michael Kinney <michael.d.kinney@intel.com>
> > > ---
> > >  .../X64/ExceptionHandlerAsm.nasm                   |
> > 29
> > > ++++++++++++++++------
> > >  1 file changed, 22 insertions(+), 7 deletions(-)
> > >
> > > diff --git
> > >
> > a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/Exception
> > > HandlerAsm.nasm
> > >
> > b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/Exception
> > > HandlerAsm.nasm
> > > index ba8993d84b..a5fde0a875 100644
> > > ---
> > >
> > a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/Exception
> > > HandlerAsm.nasm
> > > +++
> > >
> > b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/Exception
> > > HandlerAsm.nasm
> > > @@ -1,5 +1,5 @@
> > >  ;-----------------------------------------------------
> > --
> > > ----------------------- ;
> > > -; Copyright (c) 2012 - 2014, Intel Corporation. All
> > > rights reserved.<BR>
> > > +; Copyright (c) 2012 - 2018, Intel Corporation. All
> > > rights reserved.<BR>
> > >  ; This program and the accompanying materials
> > >  ; are licensed and made available under the terms and
> > > conditions of the BSD License
> > >  ; which accompanies this distribution.  The full text
> > of
> > > the license may be found at
> > > @@ -40,7 +40,8 @@ AsmIdtVectorBegin:
> > >      db      0x6a        ; push  #VectorNum
> > >      db      ($ - AsmIdtVectorBegin) /
> > ((AsmIdtVectorEnd
> > > - AsmIdtVectorBegin) / 32) ; VectorNum
> > >      push    rax
> > > -    mov     rax, ASM_PFX(CommonInterruptEntry)
> > > +    db      0x48, 0xB8
> > > +    dq      0 ;     mov     rax,
> > > ASM_PFX(CommonInterruptEntry)
> > >      jmp     rax
> > >  %endrep
> > >  AsmIdtVectorEnd:
> > > @@ -50,7 +51,9 @@ HookAfterStubHeaderBegin:
> > >  @VectorNum:
> > >      db      0          ; 0 will be fixed
> > >      push    rax
> > > -    mov     rax, HookAfterStubHeaderEnd
> > > +    db      0x48, 0xB8
> > > +JmpAbsoluteAddress:
> > > +    dq      0 ;     mov     rax,
> > HookAfterStubHeaderEnd
> > >      jmp     rax
> > >  HookAfterStubHeaderEnd:
> > >      mov     rax, rsp
> > > @@ -260,8 +263,7 @@ HasErrorCode:
> > >      ; and make sure RSP is 16-byte aligned
> > >      ;
> > >      sub     rsp, 4 * 8 + 8
> > > -    mov     rax, ASM_PFX(CommonExceptionHandler)
> > > -    call    rax
> > > +    call    ASM_PFX(CommonExceptionHandler)
> > >      add     rsp, 4 * 8 + 8
> > >
> > >      cli
> > > @@ -369,11 +371,24 @@ DoIret:
> > >  ; comments here for definition of address map
> > >  global ASM_PFX(AsmGetTemplateAddressMap)
> > >  ASM_PFX(AsmGetTemplateAddressMap):
> > > -    mov     rax, AsmIdtVectorBegin
> > > +    lea     rax, [AsmIdtVectorBegin]
> > >      mov     qword [rcx], rax
> > >      mov     qword [rcx + 0x8],  (AsmIdtVectorEnd -
> > > AsmIdtVectorBegin) / 32
> > > -    mov     rax, HookAfterStubHeaderBegin
> > > +    lea     rax, [HookAfterStubHeaderBegin]
> > >      mov     qword [rcx + 0x10], rax
> > > +
> > > +; Fix up CommonInterruptEntry address
> > > +    lea    rax, [ASM_PFX(CommonInterruptEntry)]
> > > +    lea    rcx, [AsmIdtVectorBegin]
> > > +%rep  32
> > > +    mov    qword [rcx + (JmpAbsoluteAddress -
> > > HookAfterStubHeaderBegin)], rax
> > > +    add    rcx, (AsmIdtVectorEnd - AsmIdtVectorBegin)
> > /
> > > 32
> > > +%endrep
> > > +; Fix up HookAfterStubHeaderEnd
> > > +    lea    rax, [HookAfterStubHeaderEnd]
> > > +    lea    rcx, [JmpAbsoluteAddress]
> > > +    mov    qword [rcx], rax
> > > +
> > >      ret
> > >
> > >  ;-----------------------------------------------------
> > --
> > > ------------------------------
> > > --
> > > 2.11.0.windows.1