;_ minit.asm
; Written by Walter Bright
; Digital Mars
; http://www.digitalmars.com/d/
; Placed into the Public Domain

include macros.asm

ifdef _WIN32
  DATAGRP      EQU     FLAT
else
  DATAGRP      EQU     DGROUP
endif

; Provide a default resolution for weak extern records, no way in C
; to define an omf symbol with a specific value
public __nullext
__nullext	equ 0

	extrn	__moduleinfo_array:near

; This bit of assembler is needed because, from C or D, one cannot
; specify the names of data segments. Why does this matter?
; All the ModuleInfo pointers are placed into a segment named 'FM'.
; The order in which they are placed in 'FM' is arbitrarily up to the linker.
; In order to walk all the pointers, we need to be able to find the
; beginning and the end of the 'FM' segment.
; This is done by bracketing the 'FM' segment with two other, empty,
; segments named 'FMB' and 'FME'. Since this module is the only one that
; ever refers to 'FMB' and 'FME', we get to control the order in which
; these segments appear relative to 'FM' by using a GROUP statement.
; So, we have in memory:
;	FMB	empty segment
;	FM	contains all the pointers
;	FME	empty segment
; and finding the limits of FM is as easy as taking the address of FMB
; and the address of FME.

; These segments bracket FM, which contains the list of ModuleInfo pointers
FMB     segment dword use32 public 'DATA'
FMB     ends
FM      segment dword use32 public 'DATA'
FM      ends
FME     segment dword use32 public 'DATA'
FME     ends

; This leaves room in the _fatexit() list for _moduleDtor()
XOB     segment dword use32 public 'BSS'
XOB     ends
XO      segment dword use32 public 'BSS'
	dd	?
XO      ends
XOE     segment dword use32 public 'BSS'
XOE     ends

DGROUP         group   FMB,FM,FME

	begcode minit

; extern (C) void _minit();
; Converts array of ModuleInfo pointers to a D dynamic array of them,
; so they can be accessed via D.
; Result is written to:
; extern (C) ModuleInfo[] _moduleinfo_array;

	public	__minit
__minit	proc	near
	mov	EDX,offset DATAGRP:FMB
	mov	EAX,offset DATAGRP:FME
	mov	dword ptr __moduleinfo_array+4,EDX
	sub	EAX,EDX			; size in bytes of FM segment
	shr	EAX,2			; convert to array length
	mov	dword ptr __moduleinfo_array,EAX
	ret
__minit endp

	endcode minit

	end
