paweld/fpc
1
0
Fork 0
mirror of https://gitlab.com/freepascal.org/fpc/source.git synced 2025-06-05 03:19:04 +02:00
Code Issues Packages Projects Releases Wiki Activity

* i8086 far data memory model fixes in the int 0 (div by zero) handler

Browse Source 
git-svn-id: trunk@28062 -
This commit is contained in:
nickysn 2014-06-25 16:46:58 +00:00
parent d00c67f9d3
commit ba5ececab9
1 changed files with 21 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
rtl/msdos/prt0comn.asm
View File

@ -259,39 +259,43 @@ error_msg:
FPC_INT00_HANDLER:
sub sp, 4 ; reserve space on the stack for the retf
push bx
push cx
push ds
push bp
; init ds
%ifdef __TINY__
mov bx, cs
mov bp, cs
%else
mov bx, dgroup
mov bp, dgroup
%endif
mov ds, bx
mov ds, bp
%ifdef __NEAR_DATA__
; in memory models, where SS=DS, also
; check whether we're running on the same stack
mov cx, ss
cmp bx, cx
cmp bp, cx
jne .call_previous_handler
%endif
%ifndef __FAR_CODE__
; check whether we're coming from the same code segment
mov bx, sp
mov cx, [bx + 3*2 + 6] ; get caller segment
mov bx, cs
cmp bx, cx
mov bp, sp
mov cx, [bp + 3*2 + 6] ; get caller segment
mov bp, cs
cmp bp, cx
jne .call_previous_handler
%endif
; runerror 200
mov bx, sp
mov cx, [bx + 3*2 + 4] ; get caller offset
mov bp, sp
mov cx, [bp + 3*2 + 4] ; get caller offset
%ifdef __FAR_CODE__
mov dx, [bx + 3*2 + 6] ; get caller segment
mov dx, [bp + 3*2 + 6] ; get caller segment
%endif
add sp, 3*2 + 4 + 6
pop bp
add sp, 2*2 + 4 + 6
xor ax, ax
push ax
mov ax, 200
@ -308,14 +312,14 @@ FPC_INT00_HANDLER:
%endif
.call_previous_handler:
mov bx, sp
mov bp, sp
mov cx, [__SaveInt00]
mov [ss:bx + 3*2], cx
mov [bp + 3*2], cx
mov cx, [__SaveInt00+2]
mov [ss:bx + 3*2 + 2], cx
mov [bp + 3*2 + 2], cx
pop bp
pop ds
pop cx
pop bx
retf ; jumps to the previous handler with all registers and stack intact