Category : Files from Magazines
Archive   : PJ84.ZIP
Filename : STARTUP.ASM

title start up code for assembly langauge
include asm.inc

dosseg
NULL segment para public 'BEGDATA'
NULL ends

public psp,startup,dgroup_segment

.data
psp dw 0
dgroup_segment dw 0


.data?
extb _edata,_end

.code
extn set_argc_argv,ms_dos

;; startup
;
; entry AX offset stack
; ES program segment prefix
; SS DGROUP
; exit BP 0
; may use AX,BX,CX,DX,DI,SI,DS,ES
;
startup proc
cld
mov bp,0
mov psp[bp],es

add ax,15 ; compute number of paragraphs
mov cl,4 ; in program
shr ax,cl
mov bx,ss
add bx,ax
sub bx,psp[bp]

mov ah,4Ah ; shrink program memory block for
call ms_dos ; dynamic storage system

mov dgroup_segment[bp],ss

mov al,0 ; zero bss segment
mov cx,offset DGROUP:_end
mov es,dgroup_segment[bp]
mov di,offset DGROUP:_edata
sub cx,di
rep stosb

call set_argc_argv
ret
startup endp

end