source: vbox/trunk/include/iprt/asmdefs.mac@ 97966

;; @file
; IPRT - Global YASM/NASM macros
;

;
; Copyright (C) 2006-2022 Oracle and/or its affiliates.
;
; This file is part of VirtualBox base platform packages, as
; available from https://www.virtualbox.org.
;
; This program is free software; you can redistribute it and/or
; modify it under the terms of the GNU General Public License
; as published by the Free Software Foundation, in version 3 of the
; License.
;
; This program is distributed in the hope that it will be useful, but
; WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
; General Public License for more details.
;
; You should have received a copy of the GNU General Public License
; along with this program; if not, see <https://www.gnu.org/licenses>.
;
; The contents of this file may alternatively be used under the terms
; of the Common Development and Distribution License Version 1.0
; (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
; in the VirtualBox distribution, in which case the provisions of the
; CDDL are applicable instead of those of the GPL.
;
; You may elect to license modified versions of this file under the
; terms and conditions of either the GPL or the CDDL or both.
;
; SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
;

; Special hack for bs3kit.
%ifdef RT_ASMDEFS_INC_FIRST_FILE
 %include "asmdefs-first.mac"
%endif

%ifndef ___iprt_asmdefs_mac
%define ___iprt_asmdefs_mac


;; @defgroup grp_rt_cdefs_size     Size Constants
; (Of course, these are binary computer terms, not SI.)
; @{
;; 1 K (Kilo)                     (1 024).
%define _1K                     000000400h
;; 4 K (Kilo)                     (4 096).
%define _4K                     000001000h
;; 8 K (Kilo)                     (8 192).
%define _8K                     000002000h
;; 16 K (Kilo)                   (16 384).
%define _16K                    000004000h
;; 32 K (Kilo)                   (32 768).
%define _32K                    000008000h
;; 64 K (Kilo)                   (65 536).
%define _64K                    000010000h
;; 128 K (Kilo)                 (131 072).
%define _128K                   000020000h
;; 256 K (Kilo)                 (262 144).
%define _256K                   000040000h
;; 512 K (Kilo)                 (524 288).
%define _512K                   000080000h
;; 1 M (Mega)                 (1 048 576).
%define _1M                     000100000h
;; 2 M (Mega)                 (2 097 152).
%define _2M                     000200000h
;; 4 M (Mega)                 (4 194 304).
%define _4M                     000400000h
;; 1 G (Giga)             (1 073 741 824).
%define _1G                     040000000h
;; 2 G (Giga)             (2 147 483 648).
%define _2G             00000000080000000h
;; 4 G (Giga)             (4 294 967 296).
%define _4G             00000000100000000h
;; 1 T (Tera)         (1 099 511 627 776).
%define _1T             00000010000000000h
;; 1 P (Peta)     (1 125 899 906 842 624).
%define _1P             00004000000000000h
;; 1 E (Exa)  (1 152 921 504 606 846 976).
%define _1E             01000000000000000h
;; 2 E (Exa)  (2 305 843 009 213 693 952).
%define _2E             02000000000000000h
;; @}


;;
; Define RT_STRICT for debug builds like iprt/cdefs.h does.
%ifndef RT_STRICT
 %ifdef DEBUG
  %define RT_STRICT
 %endif
%endif
%ifdef RT_NO_STRICT
 %undef RT_STRICT
%endif

;;
; Make the mask for the given bit.
%define RT_BIT(bit)        (1 << bit)

;;
; Make the mask for the given bit.
%define RT_BIT_32(bit)     (1 << bit)
;;
; Make the mask for the given bit.
%define RT_BIT_64(bit)     (1 << bit)

;;
; Makes a 32-bit unsigned (not type safe, but whatever) out of four byte values.
%define RT_MAKE_U32_FROM_U8(b0, b1, b2, b3) ( (b3 << 24) | (b2 << 16) | (b1 << 8) | b0 )

;; Preprocessor concatenation macro.
%define RT_CONCAT(a_1,a_2)              a_1 %+ a_2

;; Preprocessor concatenation macro, three arguments.
%define RT_CONCAT3(a_1,a_2,a_3)         a_1 %+ a_2 %+ a_3

;; Preprocessor concatenation macro, four arguments.
%define RT_CONCAT4(a_1,a_2,a_3,a_4)     a_1 %+ a_2 %+ a_3 %+ a_4

;;
; Trick for using RT_CONCAT and the like on %define names.
; @param 1  The name (expression.
; @param 2  The value.
%macro RT_DEFINE_EX 2
 %error 1=%1 2=%2
 %define %1 %2
%endmacro

;;
; Trick for using RT_CONCAT and the like on %xdefine names.
; @param 1  The name (expression.
; @param 2  The value.
%macro RT_XDEFINE_EX 2
 %xdefine %1 %2
%endmacro

;;
; Trick for using RT_CONCAT and the like on %undef names.
; @param 1  The name (expression.
%macro RT_UNDEF_EX 1
 %error 1=%1
 %undef %1
%endmacro

;;
; Empty define
%define RT_NOTHING

;; Define ASM_FORMAT_PE64 if applicable.
%ifdef ASM_FORMAT_PE
 %ifdef RT_ARCH_AMD64
  %define ASM_FORMAT_PE64       1
 %endif
%endif

;;
; SEH64 macros.
%ifdef RT_ASM_WITH_SEH64
 %ifndef ASM_FORMAT_PE64
  %undef RT_ASM_WITH_SEH64
 %endif
%endif

%ifdef RT_ASM_WITH_SEH64_ALT
 %ifdef ASM_FORMAT_PE64
  ;; @name Register numbers. Used with RT_CONCAT to convert macro inputs to numbers.
  ;; @{
  %define SEH64_PE_GREG_rax     0
  %define SEH64_PE_GREG_xAX     0
  %define SEH64_PE_GREG_rcx     1
  %define SEH64_PE_GREG_xCX     1
  %define SEH64_PE_GREG_rdx     2
  %define SEH64_PE_GREG_xDX     2
  %define SEH64_PE_GREG_rbx     3
  %define SEH64_PE_GREG_xBX     3
  %define SEH64_PE_GREG_rsp     4
  %define SEH64_PE_GREG_xSP     4
  %define SEH64_PE_GREG_rbp     5
  %define SEH64_PE_GREG_xBP     5
  %define SEH64_PE_GREG_rsi     6
  %define SEH64_PE_GREG_xSI     6
  %define SEH64_PE_GREG_rdi     7
  %define SEH64_PE_GREG_xDI     7
  %define SEH64_PE_GREG_r8      8
  %define SEH64_PE_GREG_r9      9
  %define SEH64_PE_GREG_r10     10
  %define SEH64_PE_GREG_r11     11
  %define SEH64_PE_GREG_r12     12
  %define SEH64_PE_GREG_r13     13
  %define SEH64_PE_GREG_r14     14
  %define SEH64_PE_GREG_r15     15
  ;; @}

  ;; @name PE unwind operations.
  ;; @{
  %define SEH64_PE_PUSH_NONVOL      0
  %define SEH64_PE_ALLOC_LARGE      1
  %define SEH64_PE_ALLOC_SMALL      2
  %define SEH64_PE_SET_FPREG        3
  %define SEH64_PE_SAVE_NONVOL      4
  %define SEH64_PE_SAVE_NONVOL_FAR  5
  %define SEH64_PE_SAVE_XMM128      8
  %define SEH64_PE_SAVE_XMM128_FAR  9
  ;; @}

  ;;
  ; Starts the unwind info for the manual SEH64 info generation.
  ; @param 1 Function name.
  %macro SEH64_ALT_START_UNWIND_INFO 1
   %assign seh64_idxOps   0
   %assign seh64_FrameReg SEH64_PE_GREG_rsp
   %assign seh64_offFrame 0
   %define asm_seh64_proc %1
   %undef  seh64_slot_bytes
  %endmacro

  ;; We keep the unwind bytes in the seh64_slot_bytes (x)define, in reverse order as per spec.
  %macro SEH64_APPEND_SLOT_PAIR 2
   %ifdef seh64_slot_bytes
    %xdefine seh64_slot_bytes %1, %2, seh64_slot_bytes
   %else
    %xdefine seh64_slot_bytes %1, %2
   %endif
  %endmacro

  ;; For multi-slot unwind info.
  %macro SEH64_APPEND_SLOT_BYTES 2+
   %rep %0
    %rotate -1
    %ifdef seh64_slot_bytes
     %xdefine seh64_slot_bytes %1, seh64_slot_bytes
    %else
     %xdefine seh64_slot_bytes %1
    %endif
   %endrep
  %endmacro

 %else
  %undef RT_ASM_WITH_SEH64_ALT
 %endif
%endif

;;
; Records a xBP push.
%macro SEH64_PUSH_xBP 0
 %ifdef RT_ASM_WITH_SEH64
        [pushreg rbp]

 %elifdef RT_ASM_WITH_SEH64_ALT
RT_CONCAT(.seh64_op_label_,seh64_idxOps):
  %ifdef ASM_FORMAT_PE64
   SEH64_APPEND_SLOT_PAIR   RT_CONCAT(.seh64_op_label_,seh64_idxOps) - .start_of_prologue, \
                            SEH64_PE_PUSH_NONVOL | (SEH64_PE_GREG_rbp << 4)
  %endif
  %assign seh64_idxOps      seh64_idxOps + 1
 %endif
%endmacro

;;
; Records a general register push.
; @param 1 Register name.
%macro SEH64_PUSH_GREG 1
 %ifdef RT_ASM_WITH_SEH64
        [pushreg %1]

 %elifdef RT_ASM_WITH_SEH64_ALT
RT_CONCAT(.seh64_op_label_,seh64_idxOps):
  %ifdef ASM_FORMAT_PE64
   SEH64_APPEND_SLOT_PAIR   RT_CONCAT(.seh64_op_label_,seh64_idxOps) - .start_of_prologue, \
                            SEH64_PE_PUSH_NONVOL | (RT_CONCAT(SEH64_PE_GREG_,%1) << 4)
  %endif
  %assign seh64_idxOps      seh64_idxOps + 1
 %endif
%endmacro

;;
; Sets xBP as frame pointer that's pointing to a stack position %1 relative to xBP.
%macro SEH64_SET_FRAME_xBP 1
 %ifdef RT_ASM_WITH_SEH64
  [setframe rbp, %1]

 %elifdef RT_ASM_WITH_SEH64_ALT
RT_CONCAT(.seh64_op_label_,seh64_idxOps):
  %ifdef ASM_FORMAT_PE64
   SEH64_APPEND_SLOT_PAIR   RT_CONCAT(.seh64_op_label_,seh64_idxOps) - .start_of_prologue, \
                            SEH64_PE_SET_FPREG | 0 ; vs2019 seems to put the offset in the info field
   %assign seh64_FrameReg   SEH64_PE_GREG_rbp
   %assign seh64_offFrame   %1
  %endif
  %assign seh64_idxOps      seh64_idxOps + 1
 %endif
%endmacro

;;
; Records an ADD xSP, %1.
%macro SEH64_ALLOCATE_STACK 1
 %ifdef RT_ASM_WITH_SEH64
        [allocstack %1]

 %elifdef RT_ASM_WITH_SEH64_ALT
RT_CONCAT(.seh64_op_label_,seh64_idxOps):
  %ifdef ASM_FORMAT_PE64
   %if (%1) & 7
    %error "SEH64_ALLOCATE_STACK must be a multiple of 8"
   %endif
   %if (%1) < 8
    %error "SEH64_ALLOCATE_STACK must have an argument that's 8 or higher."
   %elif (%1) <= 128
    SEH64_APPEND_SLOT_PAIR RT_CONCAT(.seh64_op_label_,seh64_idxOps) - .start_of_prologue, \
                           SEH64_PE_ALLOC_SMALL | ((((%1) / 8) - 1) << 4)
   %elif (%1) < 512
    SEH64_APPEND_SLOT_BYTES RT_CONCAT(.seh64_op_label_,seh64_idxOps) - .start_of_prologue, \
                            SEH64_PE_ALLOC_LARGE | 0, \
                            ((%1) / 8) & 0xff, ((%1) / 8) >> 8
   %else
    SEH64_APPEND_SLOT_BYTES RT_CONCAT(.seh64_op_label_,seh64_idxOps) - .start_of_prologue, \
                            SEH64_PE_ALLOC_LARGE | 1, \
                            (%1) & 0xff, ((%1) >> 8) & 0xff, ((%1) >> 16) & 0xff, ((%1) >> 24) & 0xff
   %endif
  %endif
  %assign seh64_idxOps      seh64_idxOps + 1
 %endif
%endmacro

%macro SEH64_INFO_HELPER 1
%if defined(%1)
        dw      %1
%endif
%endmacro

;;
; Ends the prologue.
%macro SEH64_END_PROLOGUE 0
.end_of_prologue:
 %ifdef RT_ASM_WITH_SEH64
        [endprolog]

 %elifdef RT_ASM_WITH_SEH64_ALT
  %ifdef ASM_FORMAT_PE
        ; Emit the unwind info now.
   %ifndef ASM_DEFINED_XDATA_SECTION
    %define ASM_DEFINED_XDATA_SECTION
        section .xdata rdata align=4
   %else
        section .xdata
        align   4, db 0
   %endif
.unwind_info:
        db      1                       ; version 1 (3 bit), no flags (5 bits)
        db      .end_of_prologue - .start_of_prologue

        db      (.unwind_info_array_end - .unwind_info_array) / 2
        db      seh64_FrameReg | (seh64_offFrame & 0xf0) ; framereg and offset/16.
.unwind_info_array:
   %ifdef seh64_slot_bytes
        db      seh64_slot_bytes
    %undef seh64_slot_bytes
   %endif
.unwind_info_array_end:

        ; Reset the segment
        BEGINCODE
  %endif
 %endif
%endmacro


;;
; Align code, pad with INT3.
%define ALIGNCODE(alignment) align alignment, db 0cch

;;
; Align data, pad with ZEROs.
%define ALIGNDATA(alignment) align alignment, db 0

;;
; Align BSS, pad with ZEROs.
%define ALIGNBSS(alignment) align alignment, resb 1

;;
; NAME_OVERLOAD can be defined by a .asm module to modify all the
; names created using the name macros in this files.
; This is handy when you've got some kind of template code.
%ifndef NAME_OVERLOAD
 %ifdef RT_MANGLER_PREFIX
  %define NAME_OVERLOAD(name) RT_MANGLER_PREFIX %+ name
 %else
  %define NAME_OVERLOAD(name) name
 %endif
%endif

;;
; Mangles the given name so it can be referenced using DECLASM() in the
; C/C++ world.
%ifndef ASM_FORMAT_BIN
 %ifdef RT_ARCH_X86
  %ifdef RT_OS_OS2
   %define NAME(name)   _ %+ NAME_OVERLOAD(name)
  %endif
  %ifdef RT_OS_WINDOWS
   %define NAME(name)   _ %+ NAME_OVERLOAD(name)
  %endif
 %endif
 %ifdef RT_OS_DARWIN
  %define NAME(name)    _ %+ NAME_OVERLOAD(name)
 %endif
%endif
%ifndef NAME
 %define NAME(name)     NAME_OVERLOAD(name)
%endif

;;
; Mangles the given C name so it will _import_ the right symbol.
%ifdef ASM_FORMAT_PE
 %define IMPNAME(name)  __imp_ %+ NAME(name)
%else
 %define IMPNAME(name)  NAME(name)
%endif

;;
; Gets the pointer to an imported object.
%ifdef ASM_FORMAT_PE
 %ifdef RT_ARCH_AMD64
  %define IMP(name)     qword [IMPNAME(name) wrt rip]
 %else
  %define IMP(name)     dword [IMPNAME(name)]
 %endif
%else
 %define IMP(name)      IMPNAME(name)
%endif

;;
; Gets the pointer to an imported object.
%ifdef ASM_FORMAT_PE
 %ifdef RT_ARCH_AMD64
  %define IMP_SEG(SegOverride, name)  qword [SegOverride:IMPNAME(name) wrt rip]
 %else
  %define IMP_SEG(SegOverride, name)  dword [SegOverride:IMPNAME(name)]
 %endif
%else
 %define IMP_SEG(SegOverride, name)   IMPNAME(name)
%endif

;;
; Declares an imported object for use with IMP2.
; @note May change the current section!
%macro EXTERN_IMP2 1
    extern IMPNAME(%1)
    BEGINDATA
 %ifdef ASM_FORMAT_MACHO
    g_Imp2_ %+ %1:  RTCCPTR_DEF IMPNAME(%1)
 %endif
%endmacro

;;
; Gets the pointer to an imported object, version 2.
%ifdef ASM_FORMAT_PE
 %ifdef RT_ARCH_AMD64
  %define IMP2(name)    qword [IMPNAME(name) wrt rip]
 %else
  %define IMP2(name)    dword [IMPNAME(name)]
 %endif
%elifdef ASM_FORMAT_ELF
 %ifdef PIC
  %ifdef RT_ARCH_AMD64
   %define IMP2(name)   qword [rel IMPNAME(name) wrt ..got]
  %else
   %define IMP2(name)   IMPNAME(name) wrt ..plt
  %endif
 %endif
%elifdef ASM_FORMAT_MACHO
 %define IMP2(name)     RTCCPTR_PRE [g_Imp2_ %+ name xWrtRIP]
%endif
%ifndef IMP2
 %define IMP2(name)     IMPNAME(name)
%endif


;;
; Define a label as given, with a '$' prepended to permit using instruction
; names like fdiv as labels.
%macro SAFE_LABEL 1
$%1:
%endmacro

;;
; Global marker which is DECLASM() compatible.
%macro GLOBALNAME 1
%ifndef ASM_FORMAT_BIN
global NAME(%1)
%endif
SAFE_LABEL NAME(%1)
%endmacro

;;
; Global exported marker which is DECLASM() compatible.
%macro EXPORTEDNAME 1
 %ifdef ASM_FORMAT_PE
  export %1=NAME(%1)
 %endif
 %ifdef __NASM__
  %ifdef ASM_FORMAT_OMF
   export NAME(%1) NAME(%1)
  %endif
%endif
GLOBALNAME %1
%endmacro

;;
; Same as GLOBALNAME_EX, but without the name mangling.
;
; @param %1     The symbol name - subjected to NAME().
; @param %2     ELF and PE attributes: 'function', 'object', 'data', 'notype'.
;               PE ignores all but 'function' (yasm only).  Other formats ignores
;               this completely.
; @param %3     Symbol visibility: 'hidden', 'protected', 'internal', and
;                                   RT_NOTHING (for 'default' visibility).
;               These are ELF attributes, but 'hidden' is translated to
;               'private_extern' for the Macho-O format.
;               Ignored by other formats.
;
%macro GLOBALNAME_RAW 3
%ifdef ASM_FORMAT_ELF
global %1:%2 %3

%elifdef ASM_FORMAT_PE
 %ifidn %2,function
  %ifdef __YASM__      ; nasm does not support any attributes, it errors out. So, nasm is no good with control flow guard atm.
global %1:function
  %else
global %1
  %endif
 %else
global %1
 %endif

%elifdef ASM_FORMAT_MACHO
 %ifidn %3,hidden
global %1:private_extern
 %else
global %1
 %endif

%elifndef ASM_FORMAT_BIN
global %1

%endif

%1:
%endmacro

;;
; Global marker which is DECLASM() compatible.
;
; @param %1     The symbol name - subjected to NAME().
; @param %2     ELF and PE attributes: 'function', 'object', 'data', 'notype'.
;               PE ignores all but 'function' (yasm only).  Other formats ignores
;               this completely.
; @param %3     Symbol visibility: 'hidden', 'protected', 'internal', and
;                                   RT_NOTHING (for 'default' visibility).
;               These are ELF attributes, but 'hidden' is translated to
;               'private_extern' for the Macho-O format.
;               Ignored by other formats.
;
%macro GLOBALNAME_EX 3
GLOBALNAME_RAW NAME(%1), %2, %3
%endmacro


;;
; Global exported marker, raw version w/o automatic name mangling.
;
; @param %1     The internal symbol name.
; @param %2     The external symbol name.
; @param %3     ELF and PE attributes: 'function', 'object', 'data', 'notype'.
;               PE ignores all but 'function' (yasm only).  Other formats ignores
;               this completely.
;
%macro EXPORTEDNAME_RAW 3
 %ifdef ASM_FORMAT_PE
  export %2=%1
 %endif
 %ifdef __NASM__
  %ifdef ASM_FORMAT_OMF
   export %1 %2
  %endif
%endif
GLOBALNAME_RAW %1, %3, RT_NOTHING
%endmacro

;;
; Global exported marker which is DECLASM() compatible.
;
; @param %1     The symbol name - subjected to NAME().
; @param %2     ELF and PE attributes: 'function', 'object', 'data', 'notype'.
;               PE ignores all but 'function' (yasm only).  Other formats ignores
;               this completely.
;
%macro EXPORTEDNAME_EX 2
EXPORTEDNAME_RAW NAME(%1), %1, %2
%endmacro


;;
; Begins a procedure, raw version w/o automatic name mangling.
%macro BEGINPROC_RAW 1
 %ifdef RT_ASM_WITH_SEH64_ALT
  SEH64_ALT_START_UNWIND_INFO %1
 %endif
 %ifdef RT_ASM_WITH_SEH64
global     %1:function
proc_frame %1
 %else
GLOBALNAME_RAW %1, function, hidden
 %endif
.start_of_prologue:
%endmacro

;;
; Begins a C callable (DECLASM) procedure.
%macro BEGINPROC 1
BEGINPROC_RAW NAME(%1)
%endmacro


;;
; Begins a exported procedure, raw version w/o automatic name mangling.
; @param 1  Internal name.
; @param 2  Exported name.
%macro BEGINPROC_EXPORTED_RAW 2
 %ifdef RT_ASM_WITH_SEH64_ALT
  SEH64_ALT_START_UNWIND_INFO %1
 %endif
 %ifdef RT_ASM_WITH_SEH64
  %ifdef ASM_FORMAT_PE
export  %2=%1
  %endif
global     %1:function
proc_frame %1
 %else
EXPORTEDNAME_RAW %1, %2, function
 %endif
.start_of_prologue:
%endmacro

;;
; Begins a C callable (DECLASM) exported procedure.
%macro BEGINPROC_EXPORTED 1
BEGINPROC_EXPORTED_RAW NAME(%1), %1
%endmacro


;;
; Ends a procedure, raw version w/o automatic name mangling.
%macro ENDPROC_RAW 1
 %ifdef RT_ASM_WITH_SEH64
endproc_frame
 %endif
GLOBALNAME_RAW %1 %+ _EndProc, , hidden ; no function here, this isn't a valid code flow target.
%ifdef ASM_FORMAT_ELF
 %ifndef __NASM__ ; nasm does this in the global directive.
size %1               %1 %+ _EndProc - %1
size %1 %+ _EndProc   4 ; make it non-zero to shut up warnigns from Linux's objtool.
 %endif
%endif
    db  0xCC, 0xCC, 0xCC, 0xCC

 %ifdef RT_ASM_WITH_SEH64_ALT
  %ifdef ASM_FORMAT_PE
        ; Emit the RUNTIME_FUNCTION entry.  The linker is picky here, no label.
   %ifndef ASM_DEFINED_PDATA_SECTION
    %define ASM_DEFINED_PDATA_SECTION
        section .pdata rdata align=4
   %else
        section .pdata
   %endif
        dd      %1                    wrt ..imagebase
        dd      %1 %+ _EndProc        wrt ..imagebase
        dd      %1 %+ .unwind_info    wrt ..imagebase

        ; Restore code section.
        BEGINCODE
  %endif
 %endif
%endmacro

;;
; Ends a C callable procedure.
%macro ENDPROC 1
ENDPROC_RAW NAME(%1)
%endmacro


;
; Do OMF and Mach-O/Yasm segment definitions
;
; Both format requires this to get the segment order right, in the Mach-O/Yasm case
; it's only to make sure the .bss section ends up last (it's not declared here).
;
%ifdef ASM_FORMAT_OMF
 %ifndef RT_NOINC_SEGMENTS

  ; 16-bit segments first (OMF / OS/2 specific).
  %ifdef RT_INCL_16BIT_SEGMENTS
   segment DATA16 public CLASS=FAR_DATA align=16 use16
   segment DATA16_INIT public CLASS=FAR_DATA align=16 use16
   group DGROUP16 DATA16 DATA16_INIT

   ;;
   ; Begins 16-bit data
   %macro BEGINDATA16 0
    segment DATA16
   %endmacro

   ;;
   ; Begins 16-bit init data
   %macro BEGINDATA16INIT 0
    segment DATA16_INIT
   %endmacro

   segment CODE16 public CLASS=FAR_CODE align=16 use16
   segment CODE16_INIT public CLASS=FAR_CODE align=16 use16
   group CGROUP16 CODE16 CODE16_INIT

   ;;
   ; Begins 16-bit code
   %macro BEGINCODE16 0
    segment CODE16
   %endmacro

   ;;
   ; Begins 16-bit init code
   %macro BEGINCODE16INIT 0
    segment CODE16_INIT
   %endmacro

  %endif

  ; 32-bit segments.
  segment TEXT32 public CLASS=CODE align=16 use32 flat
  segment DATA32 public CLASS=DATA align=16 use32 flat
  segment BSS32  public CLASS=BSS  align=16 use32 flat

  ; Make the TEXT32 segment default.
  segment TEXT32
 %endif ; RT_NOINC_SEGMENTS
%endif

%ifdef ASM_FORMAT_MACHO
 %ifdef __YASM__
  section .text
  section .data
 %endif
%endif


;;
; Begins code
%ifdef ASM_FORMAT_OMF
 %macro BEGINCODE 0
  segment TEXT32
 %endmacro
%else
%macro BEGINCODE 0
 section .text
%endmacro
%endif

;;
; Begins constant (read-only) data
;
; @remarks  This is mapped to the CODE section/segment when there isn't
;           any dedicated const section/segment. (There is code that
;           assumes this, so don't try change it.)
%ifdef ASM_FORMAT_OMF
 %macro BEGINCONST 0
  segment TEXT32
 %endmacro
%else
 %macro BEGINCONST 0
  %ifdef ASM_FORMAT_MACHO ;; @todo check the other guys too.
   section .rodata
  %else
   section .text
  %endif
 %endmacro
%endif

;;
; Begins initialized data
%ifdef ASM_FORMAT_OMF
 %macro BEGINDATA 0
  segment DATA32
 %endmacro
%else
%macro BEGINDATA 0
 section .data
%endmacro
%endif

;;
; Begins uninitialized data
%ifdef ASM_FORMAT_OMF
 %macro BEGINBSS 0
  segment BSS32
 %endmacro
%else
%macro BEGINBSS 0
 section .bss
%endmacro
%endif



;; @def ARCH_BITS
; Defines the bit count of the current context.
%ifndef ARCH_BITS
 %ifdef RT_ARCH_AMD64
  %define ARCH_BITS 64
 %else
  %define ARCH_BITS 32
 %endif
%endif

;; @def HC_ARCH_BITS
; Defines the host architechture bit count.
%ifndef HC_ARCH_BITS
 %ifndef IN_RC
  %define HC_ARCH_BITS ARCH_BITS
 %else
  %define HC_ARCH_BITS 32
 %endif
%endif

;; @def R3_ARCH_BITS
; Defines the host ring-3 architechture bit count.
%ifndef R3_ARCH_BITS
 %ifdef IN_RING3
  %define R3_ARCH_BITS ARCH_BITS
 %else
  %define R3_ARCH_BITS HC_ARCH_BITS
 %endif
%endif

;; @def R0_ARCH_BITS
; Defines the host ring-0 architechture bit count.
%ifndef R0_ARCH_BITS
 %ifdef IN_RING0
  %define R0_ARCH_BITS ARCH_BITS
 %else
  %define R0_ARCH_BITS HC_ARCH_BITS
 %endif
%endif

;; @def GC_ARCH_BITS
; Defines the guest architechture bit count.
%ifndef GC_ARCH_BITS
 %ifdef IN_RC
  %define GC_ARCH_BITS ARCH_BITS
 %else
  %define GC_ARCH_BITS 32
 %endif
%endif



;; @def RTHCPTR_DEF
; The pesudo-instruction used to declare an initialized pointer variable in the host context.
%if HC_ARCH_BITS == 64
 %define RTHCPTR_DEF    dq
%else
 %define RTHCPTR_DEF    dd
%endif

;; @def RTHCPTR_RES
; The pesudo-instruction used to declare (=reserve space for) an uninitialized pointer
; variable of the host context.
%if HC_ARCH_BITS == 64
 %define RTHCPTR_RES    resq
%else
 %define RTHCPTR_RES    resd
%endif

;; @def RTHCPTR_PRE
; The memory operand prefix used for a pointer in the host context.
%if HC_ARCH_BITS == 64
 %define RTHCPTR_PRE    qword
%else
 %define RTHCPTR_PRE    dword
%endif

;; @def RTHCPTR_CB
; The size in bytes of a pointer in the host context.
%if HC_ARCH_BITS == 64
 %define RTHCPTR_CB     8
%else
 %define RTHCPTR_CB     4
%endif



;; @def RTR0PTR_DEF
; The pesudo-instruction used to declare an initialized pointer variable in the ring-0 host context.
%if R0_ARCH_BITS == 64
 %define RTR0PTR_DEF    dq
%else
 %define RTR0PTR_DEF    dd
%endif

;; @def RTR0PTR_RES
; The pesudo-instruction used to declare (=reserve space for) an uninitialized pointer
; variable of the ring-0 host context.
%if R0_ARCH_BITS == 64
 %define RTR0PTR_RES    resq
%else
 %define RTR0PTR_RES    resd
%endif

;; @def RTR0PTR_PRE
; The memory operand prefix used for a pointer in the ring-0 host context.
%if R0_ARCH_BITS == 64
 %define RTR0PTR_PRE    qword
%else
 %define RTR0PTR_PRE    dword
%endif

;; @def RTR0PTR_CB
; The size in bytes of a pointer in the ring-0 host context.
%if R0_ARCH_BITS == 64
 %define RTR0PTR_CB     8
%else
 %define RTR0PTR_CB     4
%endif



;; @def RTR3PTR_DEF
; The pesudo-instruction used to declare an initialized pointer variable in the ring-3 host context.
%if R3_ARCH_BITS == 64
 %define RTR3PTR_DEF    dq
%else
 %define RTR3PTR_DEF    dd
%endif

;; @def RTR3PTR_RES
; The pesudo-instruction used to declare (=reserve space for) an uninitialized pointer
; variable of the ring-3 host context.
%if R3_ARCH_BITS == 64
 %define RTR3PTR_RES    resq
%else
 %define RTR3PTR_RES    resd
%endif

;; @def RTR3PTR_PRE
; The memory operand prefix used for a pointer in the ring-3 host context.
%if R3_ARCH_BITS == 64
 %define RTR3PTR_PRE    qword
%else
 %define RTR3PTR_PRE    dword
%endif

;; @def RTR3PTR_CB
; The size in bytes of a pointer in the ring-3 host context.
%if R3_ARCH_BITS == 64
 %define RTR3PTR_CB     8
%else
 %define RTR3PTR_CB     4
%endif



;; @def RTGCPTR_DEF
; The pesudo-instruction used to declare an initialized pointer variable in the guest context.
%if GC_ARCH_BITS == 64
 %define RTGCPTR_DEF    dq
%else
 %define RTGCPTR_DEF    dd
%endif

;; @def RTGCPTR_RES
; The pesudo-instruction used to declare (=reserve space for) an uninitialized pointer
; variable of the guest context.
%if GC_ARCH_BITS == 64
 %define RTGCPTR_RES    resq
%else
 %define RTGCPTR_RES    resd
%endif

%define RTGCPTR32_RES   resd
%define RTGCPTR64_RES   resq

;; @def RTGCPTR_PRE
; The memory operand prefix used for a pointer in the guest context.
%if GC_ARCH_BITS == 64
 %define RTGCPTR_PRE    qword
%else
 %define RTGCPTR_PRE    dword
%endif

;; @def RTGCPTR_CB
; The size in bytes of a pointer in the guest context.
%if GC_ARCH_BITS == 64
 %define RTGCPTR_CB     8
%else
 %define RTGCPTR_CB     4
%endif


;; @def RTRCPTR_DEF
; The pesudo-instruction used to declare an initialized pointer variable in the raw mode context.
%define RTRCPTR_DEF    dd

;; @def RTRCPTR_RES
; The pesudo-instruction used to declare (=reserve space for) an uninitialized pointer
; variable of the raw mode context.
%define RTRCPTR_RES    resd

;; @def RTRCPTR_PRE
; The memory operand prefix used for a pointer in the raw mode context.
%define RTRCPTR_PRE    dword

;; @def RTRCPTR_CB
; The size in bytes of a pointer in the raw mode context.
%define RTRCPTR_CB     4


;; @def RT_CCPTR_DEF
; The pesudo-instruction used to declare an initialized pointer variable in the current context.

;; @def RT_CCPTR_RES
; The pesudo-instruction used to declare (=reserve space for) an uninitialized pointer
; variable of the current context.

;; @def RT_CCPTR_PRE
; The memory operand prefix used for a pointer in the current context.

;; @def RT_CCPTR_CB
; The size in bytes of a pointer in the current context.

%ifdef IN_RC
 %define RTCCPTR_DEF        RTRCPTR_DEF
 %define RTCCPTR_RES        RTRCPTR_RES
 %define RTCCPTR_PRE        RTRCPTR_PRE
 %define RTCCPTR_CB         RTRCPTR_CB
%else
 %ifdef IN_RING0
  %define RTCCPTR_DEF       RTR0PTR_DEF
  %define RTCCPTR_RES       RTR0PTR_RES
  %define RTCCPTR_PRE       RTR0PTR_PRE
  %define RTCCPTR_CB        RTR0PTR_CB
 %else
  %define RTCCPTR_DEF       RTR3PTR_DEF
  %define RTCCPTR_RES       RTR3PTR_RES
  %define RTCCPTR_PRE       RTR3PTR_PRE
  %define RTCCPTR_CB        RTR3PTR_CB
 %endif
%endif



;; @def RTHCPHYS_DEF
; The pesudo-instruction used to declare an initialized host physical address.
%define RTHCPHYS_DEF    dq

;; @def RTHCPTR_RES
; The pesudo-instruction used to declare (=reserve space for) an uninitialized
; host physical address variable
%define RTHCPHYS_RES    resq

;; @def RTHCPTR_PRE
; The memory operand prefix used for a host physical address.
%define RTHCPHYS_PRE    qword

;; @def RTHCPHYS_CB
; The size in bytes of a host physical address.
%define RTHCPHYS_CB     8



;; @def RTGCPHYS_DEF
; The pesudo-instruction used to declare an initialized guest physical address.
%define RTGCPHYS_DEF    dq

;; @def RTGCPHYS_RES
; The pesudo-instruction used to declare (=reserve space for) an uninitialized
; guest physical address variable
%define RTGCPHYS_RES    resq

;; @def RTGCPTR_PRE
; The memory operand prefix used for a guest physical address.
%define RTGCPHYS_PRE    qword

;; @def RTGCPHYS_CB
; The size in bytes of a guest physical address.
%define RTGCPHYS_CB     8



;;
; The size of the long double C/C++ type.
; On 32-bit Darwin this is 16 bytes, on L4, Linux, OS/2 and Windows
; it's 12 bytes.
; @todo figure out what 64-bit Windows does (I don't recall right now).
%ifdef RT_ARCH_X86
 %ifdef RT_OS_DARWIN
  %define RTLRD_CB          16
 %else
  %define RTLRD_CB          12
 %endif
%else
  %define RTLRD_CB          16
%endif

;; @name Floating point constants along the lines of the iprt/types.h types.
; @note YASM does support special  the __Infinity__ and __NaN__ nasm tokens.
; @{
%define RTFLOAT32U_QNAN_PLUS    0x7fc00000
%define RTFLOAT32U_QNAN_MINUS   0xffc00000
%define RTFLOAT32U_INF_PLUS     0x7f800000
%define RTFLOAT32U_INF_MINUS    0xff800000

%define RTFLOAT64U_QNAN_PLUS    0x7ff8000000000000
%define RTFLOAT64U_QNAN_MINUS   0xfff8000000000000
%define RTFLOAT64U_INF_PLUS     0x7ff0000000000000
%define RTFLOAT64U_INF_MINUS    0xfff0000000000000
; @}



;; @def ASM_CALL64_GCC
; Indicates that we're using the GCC 64-bit calling convention.
; @see @ref sec_vboxrem_amd64_compare (in VBoxREMWrapper.cpp) for an ABI description.

;; @def ASM_CALL64_MSC
; Indicates that we're using the Microsoft 64-bit calling convention (fastcall on steroids).
; @see @ref sec_vboxrem_amd64_compare (in VBoxREMWrapper.cpp) for an ABI description.

; Note: On X86 we're using cdecl unconditionally. There is not yet any common
; calling convention on AMD64, that's why we need to support two different ones.)

%ifdef RT_ARCH_AMD64
 %ifndef ASM_CALL64_GCC
  %ifndef ASM_CALL64_MSC
   ; define it based on the object format.
   %ifdef ASM_FORMAT_PE
    %define ASM_CALL64_MSC
   %else
    %define ASM_CALL64_GCC
   %endif
  %endif
 %else
  ; sanity check.
  %ifdef ASM_CALL64_MSC
   %error "Only one of the ASM_CALL64_* defines should be defined!"
  %endif
 %endif
%else
 ;later; %ifdef ASM_CALL64_GCC
 ;later;  %error "ASM_CALL64_GCC is defined without RT_ARCH_AMD64!" ASM_CALL64_GCC
 ;later; %endif
 ;later; %ifdef ASM_CALL64_MSC
 ;later;  %error "ASM_CALL64_MSC is defined without RT_ARCH_AMD64!" ASM_CALL64_MSC
 ;later; %endif
%endif


;; @def RT_BEGINPROC
; Starts an IPRT procedure that should be exported unless IN_RT_STATIC is defined.
;
; @param    1       The function name.  Will apply NAME macro to it.
%macro RT_BEGINPROC 1
 %ifdef IN_RT_STATIC
BEGINPROC          %1
 %else
BEGINPROC_EXPORTED %1
 %endif
%endmacro ; RT_BEGINPROC


;; @def RT_NOCRT
; Symbol name wrapper for the No-CRT bits.
;
; In order to coexist in the same process as other CRTs, we need to
; decorate the symbols such that they don't conflict the ones in the
; other CRTs. The result of such conflicts / duplicate symbols can
; confuse the dynamic loader on unix like systems.
;
; @remark Always feed the name to this macro first and then pass the result
;         on to the next *NAME* macro.
;
%ifndef RT_WITHOUT_NOCRT_WRAPPERS
 %define RT_NOCRT(name) nocrt_ %+ name
%else
 %define RT_NOCRT(name) name
%endif

;; @def RT_NOCRT_BEGINPROC
; Starts a NOCRT procedure, taking care of name wrapping and aliasing.
;
; Weak aliases for regular crt (%1) names to the nocrt_ prefixed ones will be
; added when RT_WITH_NOCRT_ALIASES is defined and the output is ELF.  If
; RT_WITH_GENALIAS_NOCRT_ALIASES is undefined, strong aliases will be added for
; for non-ELF targets, otherwise it's assumed the genalias build tool will do
; the weak aliasing for us.
;
%macro RT_NOCRT_BEGINPROC 1
 %ifdef RT_WITH_NOCRT_ALIASES
BEGINPROC_EXPORTED RT_NOCRT(%1)
  %ifdef ASM_FORMAT_ELF
   ; ELF
   %ifdef RT_WITH_NOCRT_UNDERSCORE_ALIASES
global NAME(_ %+ %1):function
weak NAME(_ %+ %1)
SAFE_LABEL NAME(_ %+ %1)
   %endif
global NAME(%1):function
weak NAME(%1)
SAFE_LABEL NAME(%1)

  %elifndef RT_WITH_GENALIAS_NOCRT_ALIASES
   ; non-ELF when not using genalias.
   %ifdef RT_WITH_NOCRT_UNDERSCORE_ALIASES
GLOBALNAME _%1
   %endif
GLOBALNAME %1
  %endif
 %else  ; !RT_WITH_NOCRT_ALIASES
BEGINPROC_EXPORTED RT_NOCRT(%1)
 %endif ; !RT_WITH_NOCRT_ALIASES
%endmacro ; RT_NOCRT_BEGINPROC



;; @def xCB
; The stack unit size  / The register unit size.

;; @def xSP
; The stack pointer register (RSP or ESP).

;; @def xBP
; The base pointer register (RBP or ESP).

;; @def xAX
; RAX or EAX depending on context.

;; @def xBX
; RBX or EBX depending on context.

;; @def xCX
; RCX or ECX depending on context.

;; @def xDX
; RDX or EDX depending on context.

;; @def xDI
; RDI or EDI depending on context.

;; @def xSI
; RSI or ESI depending on context.

;; @def xWrtRIP
; 'wrt rip' for AMD64 targets, nothing for x86 ones.

%ifdef RT_ARCH_AMD64
 %define xCB 8
 %define xSP rsp
 %define xBP rbp
 %define xAX rax
 %define xBX rbx
 %define xCX rcx
 %define xDX rdx
 %define xDI rdi
 %define xSI rsi
 %define xWrtRIP wrt rip
%else
 %define xCB 4
 %define xSP esp
 %define xBP ebp
 %define xAX eax
 %define xBX ebx
 %define xCX ecx
 %define xDX edx
 %define xDI edi
 %define xSI esi
 %define xWrtRIP
%endif


;
; NASM sets __PASS__ to 0 in preprocess-only mode, and to 3 when only generating dependencies.
; YASM has no such setting which is why we must rely on kBuild to tell us what we're doing.
; For simplicity, we'll set the kBuild macro when using NASM.
;
%ifndef KBUILD_GENERATING_MAKEFILE_DEPENDENCIES
 %ifdef __NASM__
  %if __PASS__ == 0 || __PASS__ == 3
   %define KBUILD_GENERATING_MAKEFILE_DEPENDENCIES
  %endif
 %endif
%endif


;
; Some simple compile time assertions.
;
; Note! Requires new kBuild to work with YASM (see above).
;

;;
; Structure size assertion macro.
%define AssertCompileSize(a_Type, a_Size) AssertCompileSizeML a_Type, a_Size
%macro AssertCompileSizeML 2
 %ifndef KBUILD_GENERATING_MAKEFILE_DEPENDENCIES
  %assign AssertVar_cbActual   %1 %+ _size
  %assign AssertVar_cbExpected %2
  %if AssertVar_cbActual != AssertVar_cbExpected
   %error %1 is AssertVar_cbActual bytes instead of AssertVar_cbExpected
  %endif
 %endif
%endmacro

;;
; Structure size alignment assertion macro.

%define AssertCompileSizeAlignment(a_Type, a_Align) AssertCompileSizeAlignmentML a_Type, a_Align
%macro AssertCompileSizeAlignmentML 2
 %ifndef KBUILD_GENERATING_MAKEFILE_DEPENDENCIES
  %assign AssertVar_cbActual    %1 %+ _size
  %assign AssertVar_cbAlignment %2
  %if (AssertVar_cbActual & (AssertVar_cbAlignment - 1)) != 0
   %error %1 is AssertVar_cbActual bytes, expected size with AssertVar_cbAlignment bytes alignment.
  %endif
 %endif
%endmacro

;;
; Structure member offset assertion macro.
%define AssertCompileMemberOffset(a_Type, a_Member, a_off) AssertCompileMemberOffsetML a_Type, a_Member, a_off
%macro AssertCompileMemberOffsetML 3
 %ifndef KBUILD_GENERATING_MAKEFILE_DEPENDENCIES
  %assign AssertVar_offActual   %1 %+ . %+ %2
  %assign AssertVar_offExpected %3
  %if AssertVar_offActual != AssertVar_offExpected
   %error %1 %+ . %+ %2 is at AssertVar_offActual instead of AssertVar_offExpected
  %endif
 %endif
%endmacro

;;
; Structure member alignment assertion macro.
%define AssertCompileMemberAlignment(a_Type, a_Member, a_cbAlign) AssertCompileMemberAlignmentML a_Type, a_Member, a_cbAlign
%macro AssertCompileMemberAlignmentML 3
 %ifndef KBUILD_GENERATING_MAKEFILE_DEPENDENCIES
  %assign AssertVar_offActual   %1 %+ . %+ %2
  %assign AssertVar_cbAlign     %3
  %if AssertVar_offActual & (AssertVar_cbAlign - 1)
   %error %1 %+ . %+ %2 is at AssertVar_offActual, expected AssertVar_cbAlign alignment
  %endif
 %endif
%endmacro

;;
; Generic compile time expression assertion.
%define AssertCompile(a_Expr) AssertCompileML { a_Expr }
%macro AssertCompileML 1
 %ifndef KBUILD_GENERATING_MAKEFILE_DEPENDENCIES
  %if (%1) != 1
   %assign AssertVar_uResult %1
   %error %1 => AssertVar_uResult
  %endif
 %endif
%endmacro

%endif