FreeDOS/kernel/irqstack.asm

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; File:
; irqstack.asm
; Description:
; Assembly support routines for hardware stack support
;
; Copyright (c) 1997, 1998
; Svante Frey
; All Rights Reserved
;
; This file is part of DOS-C.
;
; DOS-C is free software; you can redistribute it and/or
; modify it under the terms of the GNU General Public License
; as published by the Free Software Foundation; either version
; 2, or (at your option) any later version.
;
; DOS-C is distributed in the hope that it will be useful, but
; WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
; the GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public
; License along with DOS-C; see the file COPYING. If not,
; write to the Free Software Foundation, 675 Mass Ave,
; Cambridge, MA 02139, USA.
;
; $Logfile: C:/dos-c/src/kernel/irqstack.asv $
;
; $Id$
;
; $Log$
; Revision 1.2 2000/05/08 04:30:00 jimtabor
; Update CVS to 2020
;
; Revision 1.3 1999/08/10 17:57:13 jprice
; ror4 2011-02 patch
;
; Revision 1.2 1999/04/16 12:21:22 jprice
; Steffen c-break handler changes
;
; Revision 1.1.1.1 1999/03/29 15:41:10 jprice
; New version without IPL.SYS
;
; Revision 1.4 1999/02/08 05:55:57 jprice
; Added Pat's 1937 kernel patches
;
; Revision 1.3 1999/02/01 01:48:41 jprice
; Clean up; Now you can use hex numbers in config.sys. added config.sys screen function to change screen mode (28 or 43/50 lines)
;
; Revision 1.2 1999/01/22 04:13:26 jprice
; Formating
;
; Revision 1.1.1.1 1999/01/20 05:51:01 jprice
; Imported sources
;
;
; Rev 1.2 06 Dec 1998 8:49:08 patv
; Bug fixes.
;
; Rev 1.1 22 Jan 1997 13:15:34 patv
; pre-0.92 Svante Frey bug fixes
;
; Rev 1.0 16 Jan 1997 21:43:44 patv
; Initial revision.
; $EndLog$
;
; Code for stack switching during hardware interrupts.
group TGROUP _TEXT
segment _TEXT class=CODE
old_vectors times 16 dd 0
stack_size dw 0
stack_top dw 0
stack_offs dw 0
stack_seg dw 0
irq_0: push bx
mov bx, 0 * 4
jmp short general_irq_service
irq_1: push bx
mov bx, 1 * 4
jmp short general_irq_service
irq_2: push bx
mov bx, 2 * 4
jmp short general_irq_service
irq_3: push bx
mov bx, 3 * 4
jmp short general_irq_service
irq_4: push bx
mov bx, 4 * 4
jmp short general_irq_service
irq_5: push bx
mov bx, 5 * 4
jmp short general_irq_service
irq_6: push bx
mov bx, 6 * 4
jmp short general_irq_service
irq_7: push bx
mov bx, 7 * 4
jmp short general_irq_service
irq_08: push bx
mov bx, 8 * 4
jmp short general_irq_service
irq_09: push bx
mov bx, 9 * 4
jmp short general_irq_service
irq_0a: push bx
mov bx, 0ah * 4
jmp short general_irq_service
irq_0b: push bx
mov bx, 0bh * 4
jmp short general_irq_service
irq_0c: push bx
mov bx, 0ch * 4
jmp short general_irq_service
irq_0d: push bx
mov bx, 0dh * 4
jmp short general_irq_service
irq_0e: push bx
mov bx, 0eh * 4
jmp short general_irq_service
irq_0f: push bx
mov bx, 0fh * 4
; jmp short general_irq_service
general_irq_service:
push dx
push ax
push ds
mov ax, cs
mov ds, ax
mov ax, [stack_top]
cmp ax, [stack_offs]
jbe dont_switch
mov dx, ss
mov ax, sp
mov ss, [stack_seg]
mov sp, [stack_top]
push dx ; save old SS:SP on new stack
push ax
mov ax, [stack_size]
sub [stack_top], ax
pushf
call far word [old_vectors+bx]
cli
add [stack_top], ax
pop ax ; get stored SS:SP
pop dx
mov ss, dx ; switch back to old stack
mov sp, ax
pop ds ; restore registers and return
pop ax
pop dx
pop bx
iret
dont_switch: pushf
call far word [old_vectors+bx]
pop ds
pop ax
pop dx
pop bx
iret
segment INIT_TEXT class=INIT
global _init_stacks
; VOID init_stacks(VOID FAR *stack_base, COUNT nStacks, WORD stackSize);
_init_stacks:
push bp
mov bp, sp
push ds
push di
push si
mov ax,_TEXT
mov ds,ax
mov bx, [bp+4]
mov dx, [bp+6]
mov ax, [bp+8]
mov cx, [bp+0ah]
mov [stack_size], cx
mov [stack_offs], bx
mov [stack_seg], dx
mul cx
add ax, bx
mov [stack_top], ax
xor ax, ax
mov ds, ax
mov ax, _TEXT
mov es, ax
mov di, old_vectors
mov si, 8 * 4
mov cx, 10h
rep movsw
mov si, 70h * 4
mov cx, 10h
rep movsw
push ds
pop es
mov di, 8 * 4
mov dx, irq_0
call set_vect
mov di, 70h * 4
call set_vect
pop si
pop di
pop ds
pop bp
ret
set_vect:
mov cx, 8
set_next: mov ax, dx
cli
stosw
mov ax, _TEXT
stosw
sti
add dx, irq_1 - irq_0
loop set_next
ret