diff --git a/Documentation/devicetree/booting-without-of.txt b/Documentation/devicetree/booting-without-of.txt
index 28b1c9d3d3514b9afdc27c92bd585b9982ecb6db..55fd2623445b5d1ea02ab65a5a445eb0260e6d23 100644
--- a/Documentation/devicetree/booting-without-of.txt
+++ b/Documentation/devicetree/booting-without-of.txt
@@ -13,6 +13,7 @@ Table of Contents
I - Introduction
1) Entry point for arch/powerpc
+ 2) Entry point for arch/x86
II - The DT block format
1) Header
@@ -225,6 +226,25 @@ it with special cases.
cannot support both configurations with Book E and configurations
with classic Powerpc architectures.
+2) Entry point for arch/x86
+-------------------------------
+
+ There is one single 32bit entry point to the kernel at code32_start,
+ the decompressor (the real mode entry point goes to the same 32bit
+ entry point once it switched into protected mode). That entry point
+ supports one calling convention which is documented in
+ Documentation/x86/boot.txt
+ The physical pointer to the device-tree block (defined in chapter II)
+ is passed via setup_data which requires at least boot protocol 2.09.
+ The type filed is defined as
+
+ #define SETUP_DTB 2
+
+ This device-tree is used as an extension to the "boot page". As such it
+ does not parse / consider data which is already covered by the boot
+ page. This includes memory size, reserved ranges, command line arguments
+ or initrd address. It simply holds information which can not be retrieved
+ otherwise like interrupt routing or a list of devices behind an I2C bus.
II - The DT block format
========================
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index efbae0c7521f44706a99c0412bbf188b269a29c3..b4c2e9c676232e85b6664462cfc90a22cffa6454 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -382,6 +382,8 @@ config X86_INTEL_CE
depends on X86_32
depends on X86_EXTENDED_PLATFORM
select X86_REBOOTFIXUPS
+ select OF
+ select OF_EARLY_FLATTREE
---help---
Select for the Intel CE media processor (CE4100) SOC.
This option compiles in support for the CE4100 SOC for settop
diff --git a/arch/x86/include/asm/bootparam.h b/arch/x86/include/asm/bootparam.h
index c8bfe63a06de289057321af73c114e3521d9088a..e020d88ec02dc2636800eee7203cf4a800dc2fb3 100644
--- a/arch/x86/include/asm/bootparam.h
+++ b/arch/x86/include/asm/bootparam.h
@@ -12,6 +12,7 @@
/* setup data types */
#define SETUP_NONE 0
#define SETUP_E820_EXT 1
+#define SETUP_DTB 2
/* extensible setup data list node */
struct setup_data {
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index c704b38c57a244b0067df81118b7cb2a344e1f27..ba870bb6dd8ef30ab81a317a8eb43dcb83066630 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -10,9 +10,6 @@
#include <asm/apicdef.h>
#include <asm/irq_vectors.h>
-/* Even though we don't support this, supply it to appease OF */
-static inline void irq_dispose_mapping(unsigned int virq) { }
-
static inline int irq_canonicalize(int irq)
{
return ((irq == 2) ? 9 : irq);
diff --git a/arch/x86/include/asm/prom.h b/arch/x86/include/asm/prom.h
index b4ec95f07518ec9ddbe377d14043a5d2a927a1af..e46f2a2b57a11b986ea73505f902c7d5f3acc2e7 100644
--- a/arch/x86/include/asm/prom.h
+++ b/arch/x86/include/asm/prom.h
@@ -1 +1,47 @@
-/* dummy prom.h; here to make linux/of.h's #includes happy */
+/*
+ * Definitions for Device tree / OpenFirmware handling on X86
+ *
+ * based on arch/powerpc/include/asm/prom.h which is
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _ASM_X86_PROM_H
+#define _ASM_X86_PROM_H
+#ifndef __ASSEMBLY__
+
+#include <linux/of.h>
+#include <linux/types.h>
+
+#include <asm/irq.h>
+#include <asm/atomic.h>
+#include <asm/setup.h>
+
+#ifdef CONFIG_OF
+extern void add_dtb(u64 data);
+#else
+static inline void add_dtb(u64 data) { }
+#endif
+
+extern char cmd_line[COMMAND_LINE_SIZE];
+
+#define pci_address_to_pio pci_address_to_pio
+unsigned long pci_address_to_pio(phys_addr_t addr);
+
+/**
+ * irq_dispose_mapping - Unmap an interrupt
+ * @virq: linux virq number of the interrupt to unmap
+ *
+ * FIXME: We really should implement proper virq handling like power,
+ * but that's going to be major surgery.
+ */
+static inline void irq_dispose_mapping(unsigned int virq) { }
+
+#define HAVE_ARCH_DEVTREE_FIXUPS
+
+#endif /* __ASSEMBLY__ */
+#endif
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 34244b2cd880cff373e744ec34193adb8287ab2a..6ac5036adf4251113ac9c355992f2489aedae957 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -109,6 +109,7 @@ obj-$(CONFIG_MICROCODE) += microcode.o
obj-$(CONFIG_X86_CHECK_BIOS_CORRUPTION) += check.o
obj-$(CONFIG_SWIOTLB) += pci-swiotlb.o
+obj-$(CONFIG_OF) += devicetree.o
###
# 64 bit specific files
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
new file mode 100644
index 0000000000000000000000000000000000000000..0b8f0daef9333d1db13448ab425c15bf260f1e52
--- /dev/null
+++ b/arch/x86/kernel/devicetree.c
@@ -0,0 +1,51 @@
+/*
+ * Architecture specific OF callbacks.
+ */
+#include <linux/bootmem.h>
+#include <linux/io.h>
+#include <linux/list.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+
+char __initdata cmd_line[COMMAND_LINE_SIZE];
+
+unsigned int irq_create_of_mapping(struct device_node *controller,
+ const u32 *intspec, unsigned int intsize)
+{
+ return intspec[0];
+
+}
+EXPORT_SYMBOL_GPL(irq_create_of_mapping);
+
+unsigned long pci_address_to_pio(phys_addr_t address)
+{
+ /*
+ * The ioport address can be directly used by inX / outX
+ */
+ BUG_ON(address >= (1 << 16));
+ return (unsigned long)address;
+}
+EXPORT_SYMBOL_GPL(pci_address_to_pio);
+
+void __init early_init_dt_scan_chosen_arch(unsigned long node)
+{
+ BUG();
+}
+
+void __init early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+ BUG();
+}
+
+void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+ return __alloc_bootmem(size, align, __pa(MAX_DMA_ADDRESS));
+}
+
+void __init add_dtb(u64 data)
+{
+ initial_boot_params = phys_to_virt((u64) (u32) data +
+ offsetof(struct setup_data, data));
+}
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 387b6a0c9e81b5c2536005750b79273909514c61..753136003af18e8369dc153802d0fc1b9ba40d2d 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -276,15 +276,6 @@ void smp_x86_platform_ipi(struct pt_regs *regs)
EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
-#ifdef CONFIG_OF
-unsigned int irq_create_of_mapping(struct device_node *controller,
- const u32 *intspec, unsigned int intsize)
-{
- return intspec[0];
-}
-EXPORT_SYMBOL_GPL(irq_create_of_mapping);
-#endif
-
#ifdef CONFIG_HOTPLUG_CPU
/* A cpu has been removed from cpu_online_mask. Reset irq affinities. */
void fixup_irqs(void)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 9521483ce58c11b586f3866b7d8d5bfbc555d59b..33dcbce1ab0fab86cdb872d1b33ff7e98ea55077 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -113,6 +113,7 @@
#endif
#include <asm/mce.h>
#include <asm/alternative.h>
+#include <asm/prom.h>
/*
* end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
@@ -445,6 +446,9 @@ static void __init parse_setup_data(void)
case SETUP_E820_EXT:
parse_e820_ext(data);
break;
+ case SETUP_DTB:
+ add_dtb(pa_data);
+ break;
default:
break;
}