Index: linux-2.6.11/arch/xen/i386/kernel/head.S
===================================================================
--- linux-2.6.11.orig/arch/xen/i386/kernel/head.S	2005-07-06 16:56:01.000000000 +0200
+++ linux-2.6.11/arch/xen/i386/kernel/head.S	2005-07-06 17:37:43.000000000 +0200
@@ -5,6 +5,11 @@
 	.ascii	"GUEST_OS=linux,GUEST_VER=2.6"
 	.ascii	",XEN_VER=3.0"
 	.ascii	",VIRT_BASE=0xC0000000"
+#ifdef CONFIG_X86_PAE
+	.ascii	",PAE=yes"
+#else
+	.ascii	",PAE=no"
+#endif
 	.ascii	",LOADER=generic"
 	.byte	0
 
@@ -145,10 +150,17 @@ ENTRY(cpu_gdt_table)
 	.quad 0x0000000000000000	/* 0x53 reserved */
 	.quad 0x0000000000000000	/* 0x5b reserved */
 
+#ifdef CONFIG_X86_PAE
+	.quad 0x00cfbb00000067ff	/* 0x60 kernel 4GB code at 0x00000000 */
+	.quad 0x00cfb300000067ff	/* 0x68 kernel 4GB data at 0x00000000 */
+	.quad 0x00cffb00000067ff	/* 0x73 user 4GB code at 0x00000000 */
+	.quad 0x00cff300000067ff	/* 0x7b user 4GB data at 0x00000000 */
+#else
 	.quad 0x00cfbb000000c3ff	/* 0x60 kernel 4GB code at 0x00000000 */
 	.quad 0x00cfb3000000c3ff	/* 0x68 kernel 4GB data at 0x00000000 */
 	.quad 0x00cffb000000c3ff	/* 0x73 user 4GB code at 0x00000000 */
 	.quad 0x00cff3000000c3ff	/* 0x7b user 4GB data at 0x00000000 */
+#endif
 
 	.quad 0x0000000000000000	/* 0x80 TSS descriptor */
 	.quad 0x0000000000000000	/* 0x88 LDT descriptor */
Index: linux-2.6.11/arch/xen/i386/Kconfig
===================================================================
--- linux-2.6.11.orig/arch/xen/i386/Kconfig	2005-07-06 16:56:01.000000000 +0200
+++ linux-2.6.11/arch/xen/i386/Kconfig	2005-07-06 17:37:43.000000000 +0200
@@ -557,11 +557,11 @@ config HIGHMEM4G
 	  Select this if you have a 32-bit processor and between 1 and 4
 	  gigabytes of physical RAM.
 
-#config HIGHMEM64G
-#	bool "64GB"
-#	help
-#	  Select this if you have a 32-bit processor and more than 4
-#	  gigabytes of physical RAM.
+config HIGHMEM64G
+	bool "64GB"
+	help
+	  Select this if you have a 32-bit processor and more than 4
+	  gigabytes of physical RAM.
 
 endchoice