;:ts=8
; Copyright (C) 1986,1987 by Manx Software Systems, Inc.
;
;       Initial startup routine for Aztec C.
;       NOTE: code down to "start" must be placed at beginning of
;               all programs linked with Aztec Linker using small
;               code or small data.

        mc68881
        entry   .begin
        public  .begin

        FAR code
        FAR data

.begin
        move.l  a0,-(sp)
        lea     _SysRegs,a0
        movem.l d0-d7/a0-a6,(a0)
        move.l  (sp)+,a0
        bsr     _geta4                  ;get A4
        lea     __H1_end,a1
        lea     __H2_org,a2
        cmp.l   a1,a2                   ;check if BSS and DATA together
        bne     start                   ;no, don't have to clear
        move.w  #((__H2_end-__H2_org)/4)-1,d1
        bmi     start                   ;skip if no bss
        move.l  #0,d2
loop
        move.l  d2,(a1)+                ;clear out memory
        dbra    d1,loop

start
        move.l  sp,__savsp              ;save stack pointer
        move.l  4,a6                    ;get Exec's library base pointer
        move.l  a6,_SysBase             ;put where we can get it
        movem.l d0/a0,-(sp)             ;save CLI command parameters

        btst.b  #4,$129(a6)             ;check for 68881 flag in AttnFlags
        beq     x1                      ;skip if not
        lea     x2,a5
        jsr     -30(a6)                 ;do it in supervisor mode
        bra     x1
x2
        clr.l   -(sp)
        frestore (sp)+                  ;reset the ffp stuff
        rte                             ;and return
x1

        lea     dos_name,a1             ;get name of dos library
        jsr     -408(a6)                ;open the library any version
        move.l  d0,_DOSBase             ;set it up
        bne     x3                      ;skip if okay

        move.l  #$38007,d7              ;AG_OpenLib | AO_DOSLib
        jsr     -108(a6)                ;Alert
        bra     x4
x3
        jsr     __main                  ;call the startup stuff
x4
        add.w   #8,sp                   ;pop args
        rts                             ;and return

dos_name:
        dc.b    'dos.library',0

        public  _geta4

_geta4:
        far     data
        lea     __H1_org+32766,a4
        rts

        public  __main,__H0_org

        dseg

        public  _SysRegs
        public  _SysBase,__savsp,_DOSBase
        public  __H1_org,__H1_end,__H2_org,__H2_end