diff --git a/MdePkg/Library/BaseLib/Ia32/Thunk16.s b/MdePkg/Library/BaseLib/Ia32/Thunk16.s
index 4236996226..fa7be9192d 100644
--- a/MdePkg/Library/BaseLib/Ia32/Thunk16.s
+++ b/MdePkg/Library/BaseLib/Ia32/Thunk16.s
@@ -21,171 +21,7 @@
 
 
 
-MISMATCH: "EXTERNDEF   C   mCode16Size:DWORD"
-
-MISMATCH: "CONST   SEGMENT FLAT    "DATA"  READONLY"
-
-MISMATCH: "mCode16Size     DD      _TEXT16SIZE"
-
-MISMATCH: "CONSTS"
-
-MISMATCH: "_DATA   SEGMENT FLAT    "DATA""
-
-MISMATCH: "NullSegSel      DQ      0"
-MISMATCH: "_16BitCsSel     LABEL   QWORD"
-                .word -1
-                .word 0
-                .byte 0
-                .byte 0x9b
-                .byte 0x8f              # 16-bit segment
-                .byte 0
-
-MISMATCH: "_16Gdtr         LABEL   FWORD"
-MISMATCH: "                DW      $ - offset NullSegSel - 1"
-MISMATCH: "                DD      offset NullSegSel"
-
-MISMATCH: "_DATAS"
-
-MISMATCH: "_TEXT   SEGMENT FLAT    "CODE"  PARA"
-
-MISMATCH: "IA32_REGS   STRUC   4t"
-MISMATCH: "_EDI        DD      ?"
-MISMATCH: "_ESI        DD      ?"
-MISMATCH: "_EBP        DD      ?"
-MISMATCH: "_ESP        DD      ?"
-MISMATCH: "_EBX        DD      ?"
-MISMATCH: "_EDX        DD      ?"
-MISMATCH: "_ECX        DD      ?"
-MISMATCH: "_EAX        DD      ?"
-MISMATCH: "_DS         DW      ?"
-MISMATCH: "_ES         DW      ?"
-MISMATCH: "_FS         DW      ?"
-MISMATCH: "_GS         DW      ?"
-MISMATCH: "_EFLAGS     DD      ?"
-MISMATCH: "_EIP        DD      ?"
-MISMATCH: "_CS         DW      ?"
-MISMATCH: "_SS         DW      ?"
-MISMATCH: "IA32_REGSS"
-
-MISMATCH: "_STK16      STRUC   1t"
-MISMATCH: "RetEip      DD      ?"
-MISMATCH: "RetCs       DW      ?"
-MISMATCH: "ThunkFlags  DW      ?"
-MISMATCH: "SavedEsp    DD      ?"
-MISMATCH: "SavedSs     DW      ?"
-MISMATCH: "SavedGdtr   FWORD   ?"
-MISMATCH: "SavedCr0    DD      ?"
-MISMATCH: "SavedCr4    DD      ?"
-MISMATCH: "_STK16S"
-
-.global _InternalAsmThunk16
-MISMATCH: "_InternalAsmThunk16:    USES    ebp ebx esi edi ds  es  fs  gs"
-MISMATCH: "    ASSUME  esi:PTR IA32_REGS"
-    movl    36(%esp),%esi
-MISMATCH: "    movzx   edx, [esi]._SS"
-    movl    $[esi]._ESP, %edi
-MISMATCH: "    add     edi, - sizeof (_STK16) - sizeof (IA32_REGS)"
-    pushl   %edi                        # save stack offset
-    imull   $16,%edx,%eax               # eax <- edx*16
-    addl    %eax,%edi                   # edi <- linear address of 16-bit stack
-MISMATCH: "    push    sizeof (IA32_REGS) / 4"
-    popl    %ecx
-    rep
-    movsl                               # copy context to 16-bit stack
-    popl    %ebx                        # ebx <- 16-bit stack offset
-MISMATCH: "    mov     eax, offset @F              "
-    stosl
-    movl    %cs,%eax                    # return segment
-    stosw
-    movl    40(%esp),%eax               # THUNK flags
-    stosw
-    movl    %esp,%eax
-    stosl                               # save esp
-    movl    %ss,%eax                    # save ss
-    stosw
-MISMATCH: "    sgdt    fword ptr [edi]             "
-MISMATCH: "    sidt    fword ptr [esp + 36]        "
-    movl    %cr0, %esi
-    movl    %esi,6(%edi)                # save CR0
-MISMATCH: "    and     esi, NOT 80000001h          "
-    movl    %cr4, %eax
-    movl    %eax,10(%edi)               # save CR4
-MISMATCH: "    and     al, NOT 30h                 "
-    movl    %edx,%edi                   # edi <- 16-bit stack segment
-    movl    44(%esp),%edx
-    shll    $16,%edx
-    pushl   %edx
-MISMATCH: "    lgdt    _16Gdtr                     "
-    .byte 0xea
-MISMATCH: "    DD      offset @16Bit"
-    .word 8                             # jmp far 8:@16Bit
-@16Bit: 
-    movl    %esi, %cr0                  # disable protected mode
-    movl    %eax, %cr4                  # disable PAE & PSE
-    lret
-@@: 
-    movl    %ss,%eax
-    shll    $4,%eax
-    addl    %esp,%eax                   # eax <- address of 16-bit stack
-MISMATCH: "    lss     esp, fword ptr (_STK16 ptr [esp + sizeof (IA32_REGS)]).SavedEsp"
-MISMATCH: "    lidt    fword ptr [esp + 36]        "
-    ret
-
-
-MISMATCH: "_TEXTS"
-
-MISMATCH: "_TEXT16 SEGMENT USE16   "CODE"  PARA"
-
-.global _Code16Addr
-MISMATCH: "_Code16Addr:    C"
-
-
-.global RealMode
-RealMode: 
-MISMATCH: "    ASSUME  bp:PTR _STK16"
-    movw    %di,%ss                     # set up stack
-    movl    %ebx,%esp
-MISMATCH: "    lidt    fword ptr cs:[_16Idtr - _Code16Addr]"
-    popal
-    popl    %ds
-    popl    %es
-    popl    %fs
-    popl    %gs
-    addw    $4,%sp                      # skip EFlags
-MISMATCH: "    test    (_STK16 ptr [esp + 8]).ThunkFlags, 1"
-    jz      @F
-    pushf
-@@: 
-    pushw   %cs
-MISMATCH: "    push    @FarCallRet - _Code16Addr"
-    jz      @F
-MISMATCH: "    jmp     fword ptr [esp + 6]"
-@@: 
-MISMATCH: "    jmp     fword ptr [esp + 4]"
-@FarCallRet: 
-    pushfl
-    pushw   %gs
-    pushw   %fs
-    pushw   %es
-    pushw   %ds
-    pushal
-    cli
-MISMATCH: "    lea     bp, [esp + sizeof (IA32_REGS)]"
-    .byte 0x66
-MISMATCH: "    lgdt    [bp].SavedGdtr"
-    movl    $[bp].SavedCr4, %eax
-    movl    %eax, %cr4
-    movl    $[bp].SavedCr0, %eax
-    movl    %eax, %cr0                  # restore CR0
-MISMATCH: "    jmp     fword ptr [bp].RetEip"
-
-
-MISMATCH: "_16Idtr     FWORD   (1 SHL 10) - 1"
-
-_TEXT16: 
-
-MISMATCH: "_TEXT16SIZE = _TEXT16- _Code16Addr"
-
-MISMATCH: "_TEXT16S"
-
 
+                        ##########
+                        # FIXME! #
+                        ##########