diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 377a7a595b08041fdacb1dfd43d8be206578bda8..efc7f3c87f1d9840bfc811da58811e10028a8c16 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1687,6 +1687,13 @@ endmenu
menu "Boot options"
+config USE_OF
+ bool "Flattened Device Tree support"
+ select OF
+ select OF_EARLY_FLATTREE
+ help
+ Include support for flattened device tree machine descriptions.
+
# Compressed boot loader in ROM. Yes, we really want to ask about
# TEXT and BSS so we preserve their values in the config files.
config ZBOOT_ROM_TEXT
diff --git a/arch/arm/include/asm/prom.h b/arch/arm/include/asm/prom.h
new file mode 100644
index 0000000000000000000000000000000000000000..8f1037fdc08f7dcc6ed64aa9d3f7ad95e60d838c
--- /dev/null
+++ b/arch/arm/include/asm/prom.h
@@ -0,0 +1,25 @@
+/*
+ * arch/arm/include/asm/prom.h
+ *
+ * Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#ifndef __ASMARM_PROM_H
+#define __ASMARM_PROM_H
+
+#ifdef CONFIG_OF
+
+#include <asm/setup.h>
+#include <asm/irq.h>
+
+static inline void irq_dispose_mapping(unsigned int virq)
+{
+ return;
+}
+
+#endif /* CONFIG_OF */
+#endif /* ASMARM_PROM_H */
diff --git a/arch/arm/include/asm/setup.h b/arch/arm/include/asm/setup.h
index 95176af3df8cdd1a5df238b0d738da47db316bf6..93b4702ffa0fd5cfff4c179dc923033aaadfffe7 100644
--- a/arch/arm/include/asm/setup.h
+++ b/arch/arm/include/asm/setup.h
@@ -217,6 +217,8 @@ extern struct meminfo meminfo;
#define bank_phys_end(bank) ((bank)->start + (bank)->size)
#define bank_phys_size(bank) (bank)->size
+extern int arm_add_memory(phys_addr_t start, unsigned long size);
+
#endif /* __KERNEL__ */
#endif
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 8d95446150a3e7ed0ad8fd5782f7f918529bc3d7..908c78cb1d1c4a80c0c3c6a9eb7d640b730c6828 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_ARM_THUMBEE) += thumbee.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_ARM_UNWIND) += unwind.o
obj-$(CONFIG_HAVE_TCM) += tcm.o
+obj-$(CONFIG_OF) += devtree.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_SWP_EMULATE) += swp_emulate.o
CFLAGS_swp_emulate.o := -Wa,-march=armv7-a
diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
new file mode 100644
index 0000000000000000000000000000000000000000..75e3df85b88c5cd2e27a3d2022e6503648141980
--- /dev/null
+++ b/arch/arm/kernel/devtree.c
@@ -0,0 +1,47 @@
+/*
+ * linux/arch/arm/kernel/devtree.c
+ *
+ * Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+
+#include <asm/setup.h>
+#include <asm/page.h>
+
+void __init early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+ arm_add_memory(base, size);
+}
+
+void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+ return alloc_bootmem_align(size, align);
+}
+
+/**
+ * irq_create_of_mapping - Hook to resolve OF irq specifier into a Linux irq#
+ *
+ * Currently the mapping mechanism is trivial; simple flat hwirq numbers are
+ * mapped 1:1 onto Linux irq numbers. Cascaded irq controllers are not
+ * supported.
+ */
+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);
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 006c1e884eafedbbfab80caf6a53f3c24fc47a10..109997e3fe4a603420718654f7e7ffd4ba3dcc12 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -466,7 +466,7 @@ static struct machine_desc * __init setup_machine(unsigned int nr)
/* can't use cpu_relax() here as it may require MMU setup */;
}
-static int __init arm_add_memory(phys_addr_t start, unsigned long size)
+int __init arm_add_memory(phys_addr_t start, unsigned long size)
{
struct membank *bank = &meminfo.bank[meminfo.nr_banks];
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index e5f6fc42834892e7622664b496d3aa0288eaa2ff..26c405421f4e89c67e8ea1d061e29d1e075e398d 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -15,6 +15,7 @@
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/initrd.h>
+#include <linux/of_fdt.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/memblock.h>
@@ -71,6 +72,14 @@ static int __init parse_tag_initrd2(const struct tag *tag)
__tagtable(ATAG_INITRD2, parse_tag_initrd2);
+#ifdef CONFIG_OF_FLATTREE
+void __init early_init_dt_setup_initrd_arch(unsigned long start, unsigned long end)
+{
+ phys_initrd_start = start;
+ phys_initrd_size = end - start;
+}
+#endif /* CONFIG_OF_FLATTREE */
+
/*
* This keeps memory configuration data used by a couple memory
* initialization functions, as well as show_mem() for the skipping