Index: agp_nvidia.c
===================================================================
RCS file: /home/ncvs/src/sys/pci/agp_nvidia.c,v
retrieving revision 1.6
diff -u -r1.6 agp_nvidia.c
--- agp_nvidia.c	30 May 2004 20:00:40 -0000	1.6
+++ agp_nvidia.c	17 Jan 2005 05:20:35 -0000
@@ -281,8 +281,23 @@
 {
 	u_int8_t	key;
 
-	key = ffs(pci_read_config(dev, AGP_NVIDIA_0_APSIZE, 1) & 0x0f);
-	return (1 << (24 + (key ? key : 5)));
+	key = pci_read_config(dev, AGP_NVIDIA_0_APSIZE, 1) & 0x0f;
+
+	switch (key) {
+	case 0:
+		return 512 * 1024 * 1024;
+	case 8:
+		return 256 * 1024 * 1024;
+	case 12:
+		return 128 * 1024 * 1024;
+	case 14:
+		return 64 * 1024 * 1024;
+	case 15:
+		return 32 * 1024 * 1024;
+	default:
+		device_printf(dev, "Unknown aperture size key 0x%x\n", key);
+		return 0;
+	}
 }
 
 static int