From 0a9d0188bd22fed7eb3606d307e9dfd10c3357cf Mon Sep 17 00:00:00 2001
From: Jacob Potter <jdpotter@andrew.cmu.edu>
Date: Sat, 13 Dec 2008 17:10:02 -0500
Subject: [PATCH] add checksumrect utilities

---
 aseg-paging/Makefile |  1 +
 include/fb.h         |  4 ++++
 video/checksumrect.c | 26 ++++++++++++++++++++++++++
 video/checksumrect.h |  6 ++++++
 video/tnt2.c         |  3 +++
 5 files changed, 40 insertions(+)
 create mode 100644 video/checksumrect.c
 create mode 100644 video/checksumrect.h

diff --git a/aseg-paging/Makefile b/aseg-paging/Makefile
index ae63244..73d7feb 100644
--- a/aseg-paging/Makefile
+++ b/aseg-paging/Makefile
@@ -46,6 +46,7 @@ OBJS =	../ich2/smi.o \
 	../net/rfb.o \
 	../video/tnt2.o \
 	../video/fb.o \
+	../video/checksumrect.o \
 	drivers.o \
 	../lib/minilib.o \
 	../lib/doprnt.o \
diff --git a/include/fb.h b/include/fb.h
index 9ade9e7..19dae0b 100644
--- a/include/fb.h
+++ b/include/fb.h
@@ -1,6 +1,8 @@
 #ifndef __FB_H
 #define __FB_H
 
+#include <stdint.h>
+
 struct fbdevice;
 struct vmode;
 
@@ -9,6 +11,7 @@ typedef enum {
 } format_t;
 
 typedef void (*getvmode_t)(void *);
+typedef uint32_t (*checksum_rect_t)(int x, int y, int width, int height);
 
 struct vmode {
 	int text:1;
@@ -20,6 +23,7 @@ struct fbdevice {
 	unsigned char *fbaddr;
 	void *priv;
 	getvmode_t getvmode;
+	checksum_rect_t checksum_rect;
 	struct vmode curmode;
 };
 
diff --git a/video/checksumrect.c b/video/checksumrect.c
new file mode 100644
index 0000000..f96c033
--- /dev/null
+++ b/video/checksumrect.c
@@ -0,0 +1,26 @@
+#include <stdint.h>
+#include <fb.h>
+
+uint32_t checksum_rect_generic32(int x, int y, int width, int height) {
+
+	/* Generic checksum_rect function for video modes with 32-bit pixels
+	 * (i.e. fb->curmode.bytestride = 4).
+	 */
+
+        int scanline = fb->curmode.xres * 4;
+        uint32_t * lineaddr;
+        int i, j;
+
+        uint32_t sum = 0;
+
+        for (i = 0; i < height; i++) {
+                lineaddr = (uint32_t *)(fb->fbaddr + (i + y) * scanline);
+
+                for (j = 0; j < width; j++) {
+                        sum += lineaddr[j + x];
+                }
+        }
+
+        return sum;
+}
+
diff --git a/video/checksumrect.h b/video/checksumrect.h
new file mode 100644
index 0000000..8dd2a6d
--- /dev/null
+++ b/video/checksumrect.h
@@ -0,0 +1,6 @@
+#ifndef _CHECKSUM_RECT_C
+#define _CHECKSUM_RECT_H
+
+uint32_t checksum_rect_generic32(int x, int y, int width, int height);
+
+#endif
diff --git a/video/tnt2.c b/video/tnt2.c
index 32e646a..c04b067 100644
--- a/video/tnt2.c
+++ b/video/tnt2.c
@@ -5,6 +5,8 @@
 #include <fb.h>
 #include <paging.h>
 
+#include "checksumrect.h"
+
 static void tnt2_getvmode(void *priv);
 
 static struct fbdevice tnt2_fb = {
@@ -27,6 +29,7 @@ static void tnt2_getvmode(void *priv)
 		tnt2_fb.curmode.format = FB_RGB888;
 		tnt2_fb.curmode.bytestride = 4;
 		tnt2_fb.curmode.text = 0;
+		tnt2_fb.checksum_rect = checksum_rect_generic32;
 		break;
 	case 0:
 		tnt2_fb.curmode.text = 1;
-- 
2.39.2