100 lines
No EOL
3.6 KiB
NASM
100 lines
No EOL
3.6 KiB
NASM
; =============================================================================
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; Project : Custom BIOS / ROM
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; File : bda.asm
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; Author : frater
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;
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; License : GNU General Public License v3.0 or later (GPL-3.0+)
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;
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; This program is free software: you can redistribute it and/or modify
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; it under the terms of the GNU General Public License as published by
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; the Free Software Foundation, either version 3 of the License, or
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; (at your option) any later version.
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;
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; This program is distributed in the hope that it will be useful,
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; but WITHOUT ANY WARRANTY; without even the implied warranty of
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; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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; 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 License
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; along with this program. If not, see <https://www.gnu.org/licenses/>.
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;
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; =============================================================================
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; compatible with IBM PC BIOS Data Area (BDA):
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; https://wiki.nox-rhea.org/back2root/ibm-pc-ms-dos/hardware/informations/bios_data_area
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;
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%define SEG_BDA 0x0040 ; segment BDA (historically)
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%define SEG_BDA_CUSTOM 0x0050 ; custom data (mouse, gfx cursor, etc..)
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%define SEG_GUI 0x0070 ; Segment de données UI (Safe: après Stack, avant Heap)
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%define PTR_MOUSE 0x0000
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%define PTR_GFX (PTR_MOUSE + mouse_size)
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; video related information (compatible with VGA bios)
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%define BDA_VIDEO_CURR_MODE 0x0049
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%define BDA_VIDEO_COLUMNS 0x004A
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%define BDA_VIDEO_BUF_SIZE 0x004C
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%define BDA_VIDEO_OFS_PAGE 0x004E
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;
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; information relative à la souris
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;
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%define BDA_BitPPixel 4
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%define BKG_DWORDS_PER_LINE 1 ; 1 dword stocké par ligne
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%define BKG_LINES 16
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%define BKG_TOTAL_DWORDS (BKG_LINES * BKG_DWORDS_PER_LINE) ; 16
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%define BKG_TOTAL_BYTES (BKG_TOTAL_DWORDS * 4) ; 64
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struc mouse
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.buffer resb 4 ; i8042 input buffer
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.idx resb 1 ; index in the buffer
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.packetlen resb 1 ; max buffer len (3 ou 4)
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.status resb 1 ; mouse status (button etc)
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.wheel resb 1 ; if a packet size is 4; experimental
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.x resw 1 ;
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.y resw 1 ;
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; cursor management
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.cur_x resw 1 ; preservation des x,y du background
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.cur_y resw 1 ;
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.cur_addr_start resw 1 ; adresse de départ de la sauvegarde
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.cur_drawing resb 1 ;
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.cur_counter resb 1 ; compteur de fois que le curseur a été caché (0 = visible, <0 = invisible)
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.cur_seg resw 1 ; segment / offset of the pointer
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.cur_ofs resw 1 ;
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.bkg_saved resb 1 ; background saved
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alignb 4 ; alignement 4 bytes
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; buffer for saved background
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.bkg_buffer resd 16*BDA_BitPPixel
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endstruc
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struc gfx
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.cur_x resw 1 ; x,y en pixel
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.cur_y resw 1
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.cur_mode resw 1 ; mode text
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.cur_offset resw 1 ; offset calculé pour le prochain caractère
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.cur_line_ofs resw 1 ; "interligne" +2000h ou -2000h
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.cur_shift resb 1 ; x&7 (0..7)
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endstruc
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; -----------------------------------------------------------------------------------
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; bda_setup
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; Initialise la BDA à zéro
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; -----------------------------------------------------------------------------------
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bda_setup:
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pusha
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push ds
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mov ax, SEG_BDA_CUSTOM
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mov es, ax
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mov ax, 0x5F
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mov cx,0xFF
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xor di, di
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rep stosb ; clear BDA area
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pop ds
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popa
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ret |