diff -uhr gnumach/oskit/x86/main.c gnumach-mempatch/oskit/x86/main.c
--- gnumach/oskit/x86/main.c	2002-05-28 01:01:57.000000000 +0200
+++ gnumach-mempatch/oskit/x86/main.c	2002-09-17 13:44:14.000000000 +0200
@@ -63,6 +63,8 @@
 
 #include "assert.h"
 
+#define PHYS_MEM_MAX_LIMIT		0x2fff0000 /* maximum physical memory */
+
 extern char	version[];
 
 char **kernel_argv;
@@ -108,6 +110,14 @@
    */
   picinit();
 
+#ifdef PHYS_MEM_MAX_LIMIT
+	/* ugly memory limit patch */
+	if (phys_mem_max > PHYS_MEM_MAX_LIMIT) {
+		printf("Too much physical memory 0x%x, using 0x%x\n", phys_mem_max, PHYS_MEM_MAX_LIMIT);
+		phys_mem_max = PHYS_MEM_MAX_LIMIT;
+	}
+#endif
+
   /* Tell the oskit base_* code what virtual addresses we are using
      to map the linear address space.  It can't keep using the 1:1
      kvtolin mapping once we flush the direct mapping below.