c3bd779112
It is better to use groups than segments here. git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@1343 6ac86273-5f31-0410-b378-82cca8765d1b
235 lines
6.0 KiB
NASM
235 lines
6.0 KiB
NASM
; File:
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; irqstack.asm
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; Description:
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; Assembly support routines for hardware stack support
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;
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; Copyright (c) 1997, 1998
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; Svante Frey
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; All Rights Reserved
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;
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; This file is part of DOS-C.
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;
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; DOS-C is free software; you can redistribute it and/or
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; modify it under the terms of the GNU General Public License
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; as published by the Free Software Foundation; either version
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; 2, or (at your option) any later version.
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;
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; DOS-C is distributed in the hope that it will be useful, but
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; WITHOUT ANY WARRANTY; without even the implied warranty of
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; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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; the GNU General Public License for more details.
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;
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; You should have received a copy of the GNU General Public
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; License along with DOS-C; see the file COPYING. If not,
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; write to the Free Software Foundation, 675 Mass Ave,
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; Cambridge, MA 02139, USA.
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;
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; $Id$
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;
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; Code for stack switching during hardware interrupts.
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%include "segs.inc"
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segment _IRQTEXT
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old_vectors times 16 dd 0
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stack_size dw 0
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stack_top dw 0
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stack_offs dw 0
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stack_seg dw 0
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irq_0: push bx
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mov bx, 0 * 4
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jmp short general_irq_service
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irq_1: push bx
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mov bx, 1 * 4
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jmp short general_irq_service
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irq_2: push bx
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mov bx, 2 * 4
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jmp short general_irq_service
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irq_3: push bx
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mov bx, 3 * 4
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jmp short general_irq_service
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irq_4: push bx
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mov bx, 4 * 4
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jmp short general_irq_service
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irq_5: push bx
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mov bx, 5 * 4
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jmp short general_irq_service
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irq_6: push bx
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mov bx, 6 * 4
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jmp short general_irq_service
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irq_7: push bx
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mov bx, 7 * 4
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jmp short general_irq_service
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irq_08: push bx
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mov bx, 8 * 4
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jmp short general_irq_service
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irq_09: push bx
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mov bx, 9 * 4
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jmp short general_irq_service
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irq_0a: push bx
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mov bx, 0ah * 4
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jmp short general_irq_service
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irq_0b: push bx
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mov bx, 0bh * 4
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jmp short general_irq_service
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irq_0c: push bx
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mov bx, 0ch * 4
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jmp short general_irq_service
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irq_0d: push bx
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mov bx, 0dh * 4
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jmp short general_irq_service
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irq_0e: push bx
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mov bx, 0eh * 4
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jmp short general_irq_service
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irq_0f: push bx
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mov bx, 0fh * 4
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; jmp short general_irq_service
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general_irq_service:
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push dx
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push ax
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push ds
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mov ax, cs
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mov ds, ax
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mov ax, [stack_top]
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cmp ax, [stack_offs]
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jbe dont_switch
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mov dx, ss
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mov ax, sp
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mov ss, [stack_seg]
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mov sp, [stack_top]
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push dx ; save old SS:SP on new stack
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push ax
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mov ax, [stack_size]
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sub [stack_top], ax
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pushf
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call far word [old_vectors+bx]
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cli
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add [stack_top], ax
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pop ax ; get stored SS:SP
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pop dx
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mov ss, dx ; switch back to old stack
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mov sp, ax
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pop ds ; restore registers and return
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pop ax
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pop dx
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pop bx
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iret
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dont_switch: pushf
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call far word [old_vectors+bx]
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pop ds
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pop ax
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pop dx
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pop bx
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iret
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; align to 100h to align _LOWTEXT for interrupt vectors
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; in kernel.asm
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times (100h - ($ - old_vectors)) db 0
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segment INIT_TEXT
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global _init_stacks
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; VOID init_stacks(VOID FAR *stack_base, COUNT nStacks, WORD stackSize);
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_init_stacks:
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push bp
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mov bp, sp
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push ds
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push di
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push si
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mov ax,LGROUP
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mov ds,ax
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mov bx, [bp+4]
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mov dx, [bp+6]
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mov ax, [bp+8]
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mov cx, [bp+0ah]
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mov [stack_size], cx
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mov [stack_offs], bx
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mov [stack_seg], dx
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mul cx
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add ax, bx
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mov [stack_top], ax
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xor ax, ax
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mov ds, ax
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mov ax, LGROUP
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mov es, ax
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mov di, old_vectors
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mov si, 8 * 4
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mov cx, 10h
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rep movsw
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mov si, 70h * 4
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mov cx, 10h
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rep movsw
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push ds
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pop es
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mov di, 8 * 4
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mov dx, irq_0
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call set_vect
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mov di, 70h * 4
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call set_vect
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pop si
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pop di
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pop ds
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pop bp
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ret
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set_vect:
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mov cx, 8
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set_next: mov ax, dx
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cli
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stosw
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mov ax, LGROUP
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stosw
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sti
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add dx, irq_1 - irq_0
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loop set_next
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ret
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