X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=ld45_start_nothing;a=blobdiff_plain;f=src%2Fdbglog.asm;fp=src%2Fdbglog.asm;h=0753631119ccb51900de62ad5dab7d1acfe1e00c;hp=0000000000000000000000000000000000000000;hb=371bbe72cccdd5c40d5118bd0417fab062f3699a;hpb=0216fd8105a2b94aab6eb1c013c97882cacaf0c1

diff --git a/src/dbglog.asm b/src/dbglog.asm
new file mode 100644
index 0000000..0753631
--- /dev/null
+++ b/src/dbglog.asm
@@ -0,0 +1,67 @@
+; vi:filetype=nasm ts=8 sts=8 sw=8:
+	section .text
+
+	; expects the address of a zero-terminated string in esi
+	global dbglog_str
+dbglog_str:
+	mov al, [esi]
+	cmp al, 0
+	jz .end
+	inc esi
+	call ser_putchar
+	jmp dbglog_str
+.end:	ret
+
+	global dbglog_str_num
+dbglog_str_num:
+	pusha
+	call dbglog_str
+	mov eax, [esp + 28]	; eax pushed by pusha
+
+	mov esi, numbuf + 16
+	mov byte [esi], 0
+	mov ebx, 10
+.convloop:
+	xor edx, edx
+	div ebx
+	add dl, '0'
+	dec esi
+	mov [esi], dl
+	cmp eax, 0
+	jnz .convloop
+
+	call dbglog_str
+	popa
+	ret
+
+
+UART_DATA equ 3f8h
+UART_LSTAT equ 3fdh
+LST_TREG_EMPTY equ 20h
+
+ser_putchar:
+	push edx
+	cmp al, 10
+	jnz .notlf
+	push eax
+	mov al, 13
+	call ser_putchar
+	pop eax
+
+.notlf:	mov ah, al
+	; wait until the transmit register is empty
+	mov dx, UART_LSTAT
+.wait:	in al, dx
+	and al, LST_TREG_EMPTY
+	jz .wait
+	mov dx, UART_DATA
+	mov al, ah
+	out dx, al
+
+	pop edx
+	ret
+
+
+
+	section .data
+numbuf: times 16 db 0