mirror of
https://github.com/hsoft/collapseos.git
synced 2024-11-10 02:28:06 +11:00
78 lines
1.1 KiB
NASM
78 lines
1.1 KiB
NASM
; stdio
|
|
;
|
|
; Allows other modules to print to "standard out", that is, the console through
|
|
; which the user is connected in a decoupled manner.
|
|
;
|
|
; *** REQUIREMENTS ***
|
|
; STDIO_GETC: a macro that follows GetC API
|
|
; STDIO_PUTC: a macro that follows GetC API
|
|
|
|
; *** VARIABLES ***
|
|
; Used to store formatted hex values just before printing it.
|
|
STDIO_HEX_FMT .equ STDIO_RAMSTART
|
|
STDIO_RAMEND .equ STDIO_HEX_FMT+2
|
|
|
|
; print null-terminated string pointed to by HL
|
|
printstr:
|
|
push af
|
|
push hl
|
|
|
|
.loop:
|
|
ld a, (hl) ; load character to send
|
|
or a ; is it zero?
|
|
jr z, .end ; if yes, we're finished
|
|
STDIO_PUTC
|
|
inc hl
|
|
jr .loop
|
|
|
|
.end:
|
|
pop hl
|
|
pop af
|
|
ret
|
|
|
|
; print A characters from string that HL points to
|
|
printnstr:
|
|
push bc
|
|
push hl
|
|
|
|
ld b, a
|
|
.loop:
|
|
ld a, (hl) ; load character to send
|
|
STDIO_PUTC
|
|
inc hl
|
|
djnz .loop
|
|
|
|
.end:
|
|
pop hl
|
|
pop bc
|
|
ret
|
|
|
|
printcrlf:
|
|
ld a, ASCII_CR
|
|
STDIO_PUTC
|
|
ld a, ASCII_LF
|
|
STDIO_PUTC
|
|
ret
|
|
|
|
; Print the hex char in A
|
|
printHex:
|
|
push af
|
|
push hl
|
|
ld hl, STDIO_HEX_FMT
|
|
call fmtHexPair
|
|
ld a, 2
|
|
call printnstr
|
|
pop hl
|
|
pop af
|
|
ret
|
|
|
|
; Print the hex pair in HL
|
|
printHexPair:
|
|
push af
|
|
ld a, h
|
|
call printHex
|
|
ld a, l
|
|
call printHex
|
|
pop af
|
|
ret
|