Import sources from 2011-03-30 iso image

1 files changed, 113 insertions, 0 deletions

diff --git a/sys/src/9/alphapc/cga.c b/sys/src/9/alphapc/cga.c
new file mode 100755
index 000000000..c216617b7
--- /dev/null
+++ b/sys/src/9/alphapc/cga.c
@@ -0,0 +1,113 @@
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "../port/error.h"
+#include "io.h"
+
+enum {
+	Width		= 160,
+	Height		= 25,
+
+	Attr		= 0x4f,	/* white on blue */
+};
+
+static ulong	cgabase;
+#define CGASCREENBASE	((uchar*)cgabase)
+
+static int cgapos;
+static int screeninitdone;
+static Lock cgascreenlock;
+
+static uchar
+cgaregr(int index)
+{
+	outb(0x3D4, index);
+	return inb(0x3D4+1) & 0xFF;
+}
+
+static void
+cgaregw(int index, int data)
+{
+	outb(0x3D4, index);
+	outb(0x3D4+1, data);
+}
+
+static void
+movecursor(void)
+{
+	cgaregw(0x0E, (cgapos/2>>8) & 0xFF);
+	cgaregw(0x0F, cgapos/2 & 0xFF);
+	CGASCREENBASE[cgapos+1] = Attr;
+}
+
+static void
+cgascreenputc(int c)
+{
+	int i;
+
+	if(c == '\n'){
+		cgapos = cgapos/Width;
+		cgapos = (cgapos+1)*Width;
+	}
+	else if(c == '\t'){
+		i = 8 - ((cgapos/2)&7);
+		while(i-->0)
+			cgascreenputc(' ');
+	}
+	else if(c == '\b'){
+		if(cgapos >= 2)
+			cgapos -= 2;
+		cgascreenputc(' ');
+		cgapos -= 2;
+	}
+	else{
+		CGASCREENBASE[cgapos++] = c;
+		CGASCREENBASE[cgapos++] = Attr;
+	}
+	if(cgapos >= Width*Height){
+		memmove(CGASCREENBASE, &CGASCREENBASE[Width], Width*(Height-1));
+		for (i = Width*(Height-1); i < Width*Height;) {
+			CGASCREENBASE[i++] = 0x20;
+			CGASCREENBASE[i++] = Attr;
+		}
+		cgapos = Width*(Height-1);
+	}
+	movecursor();
+}
+
+void
+screeninit(void)
+{
+	cgabase = (ulong)arch->pcimem(0xB8000, 0x8000);
+
+	cgapos = cgaregr(0x0E)<<8;
+	cgapos |= cgaregr(0x0F);
+	cgapos *= 2;
+	screeninitdone = 1;
+}
+
+static void
+cgascreenputs(char* s, int n)
+{
+	if(!screeninitdone)
+		return;
+	if(!islo()){
+		/*
+		 * Don't deadlock trying to
+		 * print in an interrupt.
+		 */
+		if(!canlock(&cgascreenlock))
+			return;
+	}
+	else
+		lock(&cgascreenlock);
+
+	while(n-- > 0)
+		cgascreenputc(*s++);
+
+	unlock(&cgascreenlock);
+}
+
+void (*screenputs)(char*, int) = cgascreenputs;