pato-z80-home-computer/pat80-computer/software/z80-assembly/os/main.asm
Daniele Verducci su MatissePenguin 2366408679 WIP PS/2 keyboard driver
2021-02-03 21:31:13 +01:00

133 lines
3.0 KiB
NASM

jp Sysinit ; Startup vector: DO NOT MOVE! Must be the first instruction
; Pat80 BIOS v0.01
; @author: Daniele Verducci
;
; MEMORY MAP
; ROM is at 0x0000
; RAM is at 0x8000
; SYSTEM VAR SPACE: 0x8000 - 0x8FFF (4kb)
; DRIVERS VAR SPACE: 0x9000 - 0x9FFF (4kb)
; APPLICATION VAR SPACE: 0xA000 - 0xFFFF (24kb)
; I/O MAP
; I/O 0 (0x00 - 0x1F) Parallel terminal (uses addr 0x00 and 0x01)
; I/O 1 (0x20 - 0x3F) Sound card (uses addr 0x20 only)
; I/O 2 (0x40 - 0x5F) PS2 Keyboard (uses 0x40 and 0x41)
; I/O 3 (0x60 - 0x7F)
; I/O 4 (0x80 - 0x9F)
; I/O 5 (0xA0 - 0xBF)
; I/O 6 (0xC0 - 0xDF)
; I/O 7 (0xE0 - 0xFF)
; **** RESET/INTERRUPT VECTOR ****
; Maskable interrupt mode 1: when the BREAK key is pressed,
; a maskable interrupt is generated and the CPU jumps to this address.
; In this way, BREAK key brings up memory monitor at any time.
ds 0x38
di ; Disable maskable interrupts.
exx ; exchange registers
ex af, af'
jp Monitor_main
; **** SYSTEM CALLS ****
; System calls provide access to low level functions (input from keyboard, output to screen etc).
; The name starts always with Sys_
ds 0x40 ; Place system calls after Z80 reset/interrupt subroutines space
; Returns ABI version.
; (ABI -> https://en.wikipedia.org/wiki/Application_binary_interface)
; Any Pat80 application should check the ABI version on startup, and refuse to run if not compatible.
; @return bc the ABI version
Sys_ABI:
ld bc, 0
ret
; Prints string
; @param BC Pointer to a null-terminated string first character
Sys_Print:
jp Term_print
; Writes a single character
; @param A Value of character to print
Sys_Printc:
jp Term_printc
; Reads a single character
; @return A The read character
Sys_Readc:
;jp Term_readc
jp PS2Keyb_readc
; Reads a line
; @return BC The pointer to a null-terminated read string
Sys_Readline:
jp Term_readline
; Emits system beep
Sys_Beep:
jp Snd_beep
; MEMORY CONFIGURATION
SYS_VAR_SPACE: EQU 0x8000
DRV_VAR_SPACE: EQU 0x9000
APP_SPACE: EQU 0xA000
; SYSTEM CONFIGURATION
IO_0: EQU 0x00
IO_1: EQU 0x20
IO_2: EQU 0x40
IO_3: EQU 0x60
IO_4: EQU 0x80
IO_5: EQU 0xA0
IO_6: EQU 0xC0
IO_7: EQU 0xE0
;include 'drivers/hd44780.asm'
;include 'drivers/keyboard.asm'
include 'drivers/ps2_keyboard.asm'
include 'drivers/arduino_terminal.asm'
include 'drivers/sn76489.asm'
include 'monitor.asm'
include 'libs/time.asm'
;include 'tests/sndtest.asm'
; **** SYSTEM INITIALIZATION ****
Sysinit:
; Init snd driver
call Snd_init
; Init video
; TODO
; Wait for audio amp to unmute
ld bc, TIME_DUR_SECOND
call Time_delay55
; Play startup sound
call Sys_Beep
; Run memory monitor
ei ; enable maskabpe interrupts
im 1 ; set interrupt mode 1 (on interrupt jumps to 0x38)
rst 0x38 ; throw fake interrupt: jump to interrupt routine to start monitor
; User exited from memory monitor without loading a program. Do nothing.
mloop:
; Main loop: do nothing.
jp mloop
; DEBUG: Echo chars
; loop:
; call Term_readc
; call Term_printc
; jp loop