--- linux-2.6.18-gentoo-r3/arch/x86_64/kernel/aperture.c	2006-11-23 13:35:27.000000000 +0100
+++ linux-2.6.18-gentoo-r3/arch/x86_64/kernel/aperture.c	2006-11-25 11:02:33.000000000 +0100
@@ -208,6 +208,15 @@ 
 		if (!early_is_k8_nb(read_pci_config(0, num, 3, 0x00)))
 			continue;
 
+
+		/* workaround buggy ASROCK BIOS, see bug #6350 */
+		aper_size = read_pci_config(0, num, 3, 0x94);
+		if (aper_size >= 0x80) {
+			aper_size &= 0x7F; //cut every byte beyond the 4G border
+			write_pci_config(0, num, 3, 0x94, aper_size);
+		}
+
+
 		iommu_detected = 1;
 		iommu_aperture = 1;