core: add decimal number write routine

Add routine to write decimal numbers, currently unused, but likely to
become useful at some time or another.

1 files changed, 56 insertions, 0 deletions

diff --git a/core/writedec.inc b/core/writedec.inc
new file mode 100644
index 00000000..235943d2
--- /dev/null
+++ b/core/writedec.inc
@@ -0,0 +1,56 @@
+;; -----------------------------------------------------------------------
+;;
+;;   Copyright 1994-2008 H. Peter Anvin - All Rights Reserved
+;;
+;;   This program is free software; you can redistribute it and/or modify
+;;   it under the terms of the GNU General Public License as published by
+;;   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
+;;   Boston MA 02111-1307, USA; either version 2 of the License, or
+;;   (at your option) any later version; incorporated herein by reference.
+;;
+;; -----------------------------------------------------------------------
+
+;;
+;; writedec.inc
+;;
+;; Write decimal numbers to the console
+;;
+
+		section .text
+;
+; writedec[bwl]: Write a hex number in (AL, AX, EAX) to the console
+;
+writedecb:
+		pushad
+		movzx eax,al
+		jmp short writedec_common
+writedecw:
+		pushad
+		movzx eax,ax
+		jmp short writedec_common
+writedecl:
+		pushad
+writedec_common:
+		pushfd
+		mov ebx,10		; Conversion base
+		xor cx,cx		; Number of digits
+
+.cloop:
+		div ebx
+		inc cx
+		push dx
+		and eax,eax
+		jnz .cloop
+
+.dloop:
+		pop ax
+		add al,'0'
+		call writechr
+		loop .dloop
+
+		popfd
+		popad
+		ret
+
+writechr:
+		ret