diff options
Diffstat (limited to 'mubios/arch')
| -rw-r--r-- | mubios/arch/interrupt.S | 50 | ||||
| -rw-r--r-- | mubios/arch/irq.S | 29 |
2 files changed, 79 insertions, 0 deletions
diff --git a/mubios/arch/interrupt.S b/mubios/arch/interrupt.S new file mode 100644 index 0000000..7cb3f4b --- /dev/null +++ b/mubios/arch/interrupt.S @@ -0,0 +1,50 @@ +# RCC-Project +# +# Copyright (C) 2026 Richard Qin +# +# This file is part of RCC-Project. +# +# RCC-Project 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 3 of the License, or (at your option) any +# later version. +# +# RCC-Project 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 +# RCC-Project; see the file COPYING. If not see +# <http://www.gnu.org/licenses/>. + + .intel_syntax noprefix + .code16 + + .section .text16.irq, "ax" + + .global int1a_entry + .type int1a_entry, @function + +int1a_entry: + cmp ah, 0x00 + jne int1a_return + + push ds + push bx + + xor bx, bx + mov ds, bx + + mov bx, 0x046C + mov cx, word ptr [bx + 2] + mov dx, word ptr [bx] + + mov al, byte ptr [0x0470] + mov byte ptr [0x0470], 0 + mov ah, 0x00 + + pop bx + pop ds + +int1a_return: + iret diff --git a/mubios/arch/irq.S b/mubios/arch/irq.S index 6eea350..dbde8ad 100644 --- a/mubios/arch/irq.S +++ b/mubios/arch/irq.S @@ -20,6 +20,12 @@ .intel_syntax noprefix .code16 + .equ BDA_TIMER_COUNTER, 0x046C + .equ BDA_TIMER_ROLLOVER, 0x0470 + + .equ TIMER_TICKS_PER_DAY_LOW, 0x00B0 + .equ TIMER_TICKS_PER_DAY_HIGH, 0x0018 + .section .text16.irq, "ax" .global irq0_entry @@ -27,11 +33,34 @@ irq0_entry: push ax + push bx + + xor bx, bx + mov ds, bx + + mov bx, BDA_TIMER_COUNTER + inc word ptr [bx] + + jnz irq0_send_eoi + + inc word ptr [bx + 2] + + cmp word ptr [bx + 2], TIMER_TICKS_PER_DAY_HIGH + jne irq0_send_eoi + + cmp word ptr [bx], TIMER_TICKS_PER_DAY_LOW + jne irq0_send_eoi + + mov word ptr [bx], 0 + mov word ptr [bx + 2], 0 + mov byte ptr [BDA_TIMER_ROLLOVER], 1 +irq0_send_eoi: # Acknowledge IRQ0 on the master PIC. mov al, 0x20 out 0x20, al + pop bx pop ax iret |