92 lines
1.5 KiB
Plaintext
92 lines
1.5 KiB
Plaintext
|
|
%define KBD_STATUS 0x1ffc
|
|
%define KBD_CODE 0x1ffe
|
|
%define VCD 0x2000
|
|
|
|
%define FL_EQ 0x2
|
|
%define FL_EQ 0x4
|
|
|
|
%define KBD_FLAG_IS_RELEASE 0x1
|
|
|
|
mov rsp, 0x1000
|
|
mov rbp, rsp
|
|
|
|
mov r0, 512
|
|
mov r1, 1
|
|
dskr r0, r1
|
|
|
|
; setup video character display (VCD)
|
|
; descriptor table structure:
|
|
; [addr + 0] memory map base
|
|
mov r0, VCD
|
|
mov [0x700], r0
|
|
lvcd 0x700
|
|
|
|
; setup keyboard (KBD)
|
|
; descriptor table structure:
|
|
; [addr + 0] status address
|
|
; [addr + 2] keycode address
|
|
; [addr + 4] keyboard interrupt handler
|
|
mov r0, KBD_STATUS
|
|
mov [0x702], r0
|
|
mov r0, KBD_CODE
|
|
mov [0x704], r0
|
|
mov r0, key_press_int
|
|
mov [0x706], r0
|
|
lkbd 0x702
|
|
|
|
; character counter
|
|
mov r0, 0
|
|
mov [0x600], r0
|
|
|
|
main_loop:
|
|
hlt
|
|
jmp main_loop
|
|
|
|
key_press_int:
|
|
mov r0, [KBD_STATUS]
|
|
and r0, r0, KBD_FLAG_IS_RELEASE
|
|
jnz r0, .leave
|
|
|
|
mov r0, [0x600]
|
|
add r0, r0, VCD
|
|
mov r1, [KBC_CODE]
|
|
cmp r1, 44 ; spacebar
|
|
mov r2, rfl
|
|
and r2, r2, FL_EQ
|
|
jnz r2, .incr
|
|
add r1, r1, 61
|
|
mov byte [r0], r1
|
|
.incr:
|
|
mov r0, [0x600]
|
|
add r0, r0, 1
|
|
mov [0x600], r0
|
|
.leave:
|
|
reti
|
|
|
|
scancode_to_char:
|
|
cmp r1, 61
|
|
|
|
mov r2, rfl
|
|
and r2, r2, FL_LT
|
|
jnz .not_letter
|
|
|
|
; if r1 > 86 { goto .not_letter }
|
|
cmp r1, 86
|
|
mov r2, rfl
|
|
xor r2, 0xffff
|
|
and r2, r2, FL_EQ | FL_LT
|
|
|
|
|
|
mov r4, rfl
|
|
and r4, r4, FL_EQ
|
|
shr r4, r4, 2
|
|
|
|
.not_letter:
|
|
|
|
|
|
61 >= 61
|
|
|
|
; vim: syntax=nasm
|
|
|