Category : Assembly Language Source Code
Archive   : EMAC15ES.ZIP
Filename : EXECUTE.ASM

;History:14,1
;Sun Mar 26 20:54:16 1989 remove reference to textseg.
;03-27-88 14:27:20 remove execute_filter code.
;03-13-88 12:26:39 remove the execute filter stuff.
stderr equ 1

.xlist
include memory.def

data segment byte public

extrn phd_seg: word

fcb_struc struc
fcb_drive db 0
fcb_fname db ' '
fcb_ext db ' '
fcb_curblk dw 0
fcb_recsz dw 0
fcb_filsz dw 0,0
fcb_date dw 0
fcb_time dw 0
fcb_res dd ?,?
fcb_currec db 0
fcb_ranrec dw 0,0
fcb_struc ends

segofs struc
offs dw ?
segm dw ?
segofs ends


data ends


code segment byte public
;all the routines in this segment are entered with ds=data, es=data
assume cs:code, ds:data, es:data, ss:data

;the following externs are in 'buffers'
extrn compact_buffers: near
extrn uncompact_buffers: near

;the following externs are in 'memory'
extrn read_mark: near
extrn del_to_mark: near
extrn insert_string$: near

;the following externs are in 'redisplay'
extrn redisplay: near
extrn paint_screen: near

extrn init_entry: near
extrn uninit_exit: near

extrn abort_fatal: near ;fatal error handler

our_sp dw ?
our_ss dw ?

parameters dw 0
dw 80h, ?
dw 5ch, ?
dw 6ch, ?

copy_to_dioa:
;enter with si, cx->command.
;exit with cs:phd_dioa set to the string.
push es
mov es,phd_seg ;copy the command to phd_dioa+1
mov di,80h+1
if 0
mov ax,3700h ;get the switch char.
int 21h
mov al,dl
stosb
mov al,'C' ;store -C or /C.
stosb
endif
rep movsb
mov al,CR ;store the terminating CR.
stosb
sub di,80h+1+1 ;don't count the CR.
mov ax,di
mov es:[80h],al ;store the count.
pop es ;restore es.
ret


public execute_program
execute_program:
;enter with si, cx->path of filter to execute, di ->null terminated filename.
;exit with ax=return result.
push di
call copy_to_dioa
pop di
call actually_execute
ret


actually_execute:
;enter with di -> filename, cs:phd_dioa = arguments.
push di
call uninit_exit
pop di

push ds
push es

push di
call compact_buffers ;make room for the program.
pop di

mov dx,phd_seg ;subtract off the allocated segment.
sub bx,dx
mov es,dx ;get es=allocated segment.
assume es:nothing

mov ah,4ah ;reduce ourself in size.
int 21h

mov our_sp,sp ;remember our stack.
mov our_ss,ss

mov ds,phd_seg ;move ds first because we need ds.
assume ds:nothing
mov es,phd_seg
assume es:nothing

mov dx,di ;set up to execute the program.

mov ax,2901h ;parse fcb1.
mov si,81h ;->phd_sdioa.
mov di,5ch ;->phd_fcb1
int 21h

mov ax,2901h ;parse fcb2.
mov di,6ch ;->phd_fcb2.
int 21h

push ss ;ss:dx -> filename to execute.
pop ds
assume ds:data
push cs
pop es
assume es:code
mov bx,offset parameters
mov ax,phd_seg
mov es:[bx]+4,ax ;use original phd parameters.
mov es:[bx]+8,ax
mov es:[bx]+12,ax
mov ax,4b00h
int 21h
jc actually_execute_1
xor ax,ax ;make sure ax is zero if no errors.
actually_execute_1:

cli ;get our stack back.
mov ss,cs:our_ss
mov sp,cs:our_sp
sti

push ax

mov bx,0ffffh ;now grab all of memory again.
mov es,phd_seg
mov ah,4ah ;see how much is available.
int 21h
mov ah,4ah ;grab all of it.
int 21h

push cs ;reset the fatal error address.
pop ds
mov dx,offset abort_fatal
mov ax,2524h
int 21h

mov ax,33h*256+1 ;turn break checking back off.
mov dl,0 ; in case someone turned it on.
int 21h

pop ax

pop es
pop ds
assume ds:data, es:data

push ax
call uncompact_buffers ;make room for the text again.
call init_entry
call paint_screen
pop ax
ret


code ends

end