SpaceBarOS/DCPU

gistfile1.dasm16

;
; SpaceBarOS/DCPU
; (C) Iain R. Learmonth 2012. All rights reserved.
;
; Requires:
;     DCPU-16
;     LEM1802
;
; Tasks:
;     Memory management
;     Terminal driver
;     Virtual file system
;     
;

jsr detect_hardware

; print a welcome message
set a, welcome
jsr kprint

; update the monitor
set a, 0
set b, 0x8000
hwi [monitor]

:end
; do some halting
set pc, end

:kprint
; print a null-terminated string
; whose first character is at the
; address stored in A register
set b, 0x8000

:kprint_loop
ife [a], 0x0000
set pc, pop
set [b], [a]
bor [b], 0x7000
add a, 1
add b, 1
set pc, kprint_loop

:detect_hardware
; how many devices are there
hwn i

:detect_hardware_loop
; what are you
hwq i

; is it a monitor
ife a, 0xf615
ife b, 0x7349
set [monitor], i

sub i, 1 ;next hardware id

; are we done
ife i, 0xffff
set pc, pop

; check next device
set pc, detect_hardware_loop

:monitor DAT 0 ; Monitor Hardware ID
:welcome DAT "Welcome to SpaceBarOS/DCPU", 0