# 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

	.global int10_entry
	.type int10_entry, @function

int10_entry:
	cmp ah, 0x0E
	jne int10_return

	push bp
	mov bp, sp

	push ax
	push bx
	push dx
	push si
	push di
	push ds
	push es

	xor ax, ax
	mov ds, ax

	mov ax, 0xB800
	mov es, ax

	mov si, 0x0050
	mov dx, word ptr [si]

	mov al, byte ptr [bp - 2]
	mov bl, byte ptr [bp - 4]

	cmp al, 0x0D
	je int10_carriage_return

	cmp al, 0x0A
	je int10_line_feed

	cmp al, 0x08
	je int10_backspace

	mov di, dx
	shl di, 1
	mov ah, bl
	mov word ptr es:[di], ax
	inc dx
	jmp int10_store_cursor

	
int10_carriage_return:
	mov ax, dx
	mov si, 80
	xor dx, dx
	div si
	mul si
	mov dx, ax
	jmp int10_store_cursor

int10_line_feed:
	add dx, 80
	jmp int10_store_cursor

int10_backspace:
	cmp dx, 0
	je int10_store_cursor

	dec dx
	mov di, dx
	shl di, 1
	mov al, 0x20
	mov ah, bl
	mov word ptr es:[di], ax

int10_store_cursor:
	cmp dx, 2000
	jb int10_save_cursor

	xor dx, dx

int10_save_cursor:
	mov word ptr [0x0050], dx

	pop es
	pop ds
	pop di
	pop si
	pop dx
	pop bx
	pop ax
	pop bp

int10_return:
	iret