diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index 6e1e5212f058..c13b982084a3 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -14,4 +14,10 @@ obj-$(CONFIG_OF_RESOLVE)  += resolver.o
 obj-$(CONFIG_OF_OVERLAY) += overlay.o
 obj-$(CONFIG_OF_NUMA) += of_numa.o
 
+ifdef CONFIG_KEXEC_FILE
+ifdef CONFIG_OF_FLATTREE
+obj-y	+= kexec.o
+endif
+endif
+
 obj-$(CONFIG_OF_UNITTEST) += unittest-data/
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
new file mode 100644
index 000000000000..264cac0fd4cd
--- /dev/null
+++ b/drivers/of/kexec.c
@@ -0,0 +1,265 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Arm Limited
+ *
+ * Based on arch/arm64/kernel/machine_kexec_file.c:
+ *  Copyright (C) 2018 Linaro Limited
+ *
+ * And arch/powerpc/kexec/file_load.c:
+ *  Copyright (C) 2016  IBM Corporation
+ */
+
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/libfdt.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/random.h>
+#include <linux/types.h>
+
+/* relevant device tree properties */
+#define FDT_PROP_KEXEC_ELFHDR	"linux,elfcorehdr"
+#define FDT_PROP_MEM_RANGE	"linux,usable-memory-range"
+#define FDT_PROP_INITRD_START	"linux,initrd-start"
+#define FDT_PROP_INITRD_END	"linux,initrd-end"
+#define FDT_PROP_BOOTARGS	"bootargs"
+#define FDT_PROP_KASLR_SEED	"kaslr-seed"
+#define FDT_PROP_RNG_SEED	"rng-seed"
+#define RNG_SEED_SIZE		128
+
+/*
+ * Additional space needed for the FDT buffer so that we can add initrd,
+ * bootargs, kaslr-seed, rng-seed, useable-memory-range and elfcorehdr.
+ */
+#define FDT_EXTRA_SPACE 0x1000
+
+/**
+ * fdt_find_and_del_mem_rsv - delete memory reservation with given address and size
+ *
+ * @fdt:	Flattened device tree for the current kernel.
+ * @start:	Starting address of the reserved memory.
+ * @size:	Size of the reserved memory.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int fdt_find_and_del_mem_rsv(void *fdt, unsigned long start, unsigned long size)
+{
+	int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
+
+	for (i = 0; i < num_rsvs; i++) {
+		u64 rsv_start, rsv_size;
+
+		ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
+		if (ret) {
+			pr_err("Malformed device tree.\n");
+			return -EINVAL;
+		}
+
+		if (rsv_start == start && rsv_size == size) {
+			ret = fdt_del_mem_rsv(fdt, i);
+			if (ret) {
+				pr_err("Error deleting device tree reservation.\n");
+				return -EINVAL;
+			}
+
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+/*
+ * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
+ *
+ * @image:		kexec image being loaded.
+ * @initrd_load_addr:	Address where the next initrd will be loaded.
+ * @initrd_len:		Size of the next initrd, or 0 if there will be none.
+ * @cmdline:		Command line for the next kernel, or NULL if there will
+ *			be none.
+ * @extra_fdt_size:	Additional size for the new FDT buffer.
+ *
+ * Return: fdt on success, or NULL errno on error.
+ */
+void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
+				   unsigned long initrd_load_addr,
+				   unsigned long initrd_len,
+				   const char *cmdline, size_t extra_fdt_size)
+{
+	void *fdt;
+	int ret, chosen_node;
+	const void *prop;
+	size_t fdt_size;
+
+	fdt_size = fdt_totalsize(initial_boot_params) +
+		   (cmdline ? strlen(cmdline) : 0) +
+		   FDT_EXTRA_SPACE +
+		   extra_fdt_size;
+	fdt = kvmalloc(fdt_size, GFP_KERNEL);
+	if (!fdt)
+		return NULL;
+
+	ret = fdt_open_into(initial_boot_params, fdt, fdt_size);
+	if (ret < 0) {
+		pr_err("Error %d setting up the new device tree.\n", ret);
+		goto out;
+	}
+
+	/* Remove memory reservation for the current device tree. */
+	ret = fdt_find_and_del_mem_rsv(fdt, __pa(initial_boot_params),
+				       fdt_totalsize(initial_boot_params));
+	if (ret == -EINVAL) {
+		pr_err("Error removing memory reservation.\n");
+		goto out;
+	}
+
+	chosen_node = fdt_path_offset(fdt, "/chosen");
+	if (chosen_node == -FDT_ERR_NOTFOUND)
+		chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
+					      "chosen");
+	if (chosen_node < 0) {
+		ret = chosen_node;
+		goto out;
+	}
+
+	ret = fdt_delprop(fdt, chosen_node, FDT_PROP_KEXEC_ELFHDR);
+	if (ret && ret != -FDT_ERR_NOTFOUND)
+		goto out;
+	ret = fdt_delprop(fdt, chosen_node, FDT_PROP_MEM_RANGE);
+	if (ret && ret != -FDT_ERR_NOTFOUND)
+		goto out;
+
+	/* Did we boot using an initrd? */
+	prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL);
+	if (prop) {
+		u64 tmp_start, tmp_end, tmp_size;
+
+		tmp_start = fdt64_to_cpu(*((const fdt64_t *) prop));
+
+		prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", NULL);
+		if (!prop) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		tmp_end = fdt64_to_cpu(*((const fdt64_t *) prop));
+
+		/*
+		 * kexec reserves exact initrd size, while firmware may
+		 * reserve a multiple of PAGE_SIZE, so check for both.
+		 */
+		tmp_size = tmp_end - tmp_start;
+		ret = fdt_find_and_del_mem_rsv(fdt, tmp_start, tmp_size);
+		if (ret == -ENOENT)
+			ret = fdt_find_and_del_mem_rsv(fdt, tmp_start,
+						       round_up(tmp_size, PAGE_SIZE));
+		if (ret == -EINVAL)
+			goto out;
+	}
+
+	/* add initrd-* */
+	if (initrd_load_addr) {
+		ret = fdt_setprop_u64(fdt, chosen_node, FDT_PROP_INITRD_START,
+				      initrd_load_addr);
+		if (ret)
+			goto out;
+
+		ret = fdt_setprop_u64(fdt, chosen_node, FDT_PROP_INITRD_END,
+				      initrd_load_addr + initrd_len);
+		if (ret)
+			goto out;
+
+		ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
+		if (ret)
+			goto out;
+
+	} else {
+		ret = fdt_delprop(fdt, chosen_node, FDT_PROP_INITRD_START);
+		if (ret && (ret != -FDT_ERR_NOTFOUND))
+			goto out;
+
+		ret = fdt_delprop(fdt, chosen_node, FDT_PROP_INITRD_END);
+		if (ret && (ret != -FDT_ERR_NOTFOUND))
+			goto out;
+	}
+
+	if (image->type == KEXEC_TYPE_CRASH) {
+		/* add linux,elfcorehdr */
+		ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+				FDT_PROP_KEXEC_ELFHDR,
+				image->arch.elf_load_addr,
+				image->arch.elf_headers_sz);
+		if (ret)
+			goto out;
+
+		/*
+		 * Avoid elfcorehdr from being stomped on in kdump kernel by
+		 * setting up memory reserve map.
+		 */
+		ret = fdt_add_mem_rsv(fdt, image->arch.elf_load_addr,
+				      image->arch.elf_headers_sz);
+		if (ret)
+			goto out;
+
+		/* add linux,usable-memory-range */
+		ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+				FDT_PROP_MEM_RANGE,
+				crashk_res.start,
+				crashk_res.end - crashk_res.start + 1);
+		if (ret)
+			goto out;
+	}
+
+	/* add bootargs */
+	if (cmdline) {
+		ret = fdt_setprop_string(fdt, chosen_node, FDT_PROP_BOOTARGS, cmdline);
+		if (ret)
+			goto out;
+	} else {
+		ret = fdt_delprop(fdt, chosen_node, FDT_PROP_BOOTARGS);
+		if (ret && (ret != -FDT_ERR_NOTFOUND))
+			goto out;
+	}
+
+	/* add kaslr-seed */
+	ret = fdt_delprop(fdt, chosen_node, FDT_PROP_KASLR_SEED);
+	if (ret == -FDT_ERR_NOTFOUND)
+		ret = 0;
+	else if (ret)
+		goto out;
+
+	if (rng_is_initialized()) {
+		u64 seed = get_random_u64();
+
+		ret = fdt_setprop_u64(fdt, chosen_node, FDT_PROP_KASLR_SEED, seed);
+		if (ret)
+			goto out;
+	} else {
+		pr_notice("RNG is not initialised: omitting \"%s\" property\n",
+				FDT_PROP_KASLR_SEED);
+	}
+
+	/* add rng-seed */
+	if (rng_is_initialized()) {
+		void *rng_seed;
+
+		ret = fdt_setprop_placeholder(fdt, chosen_node, FDT_PROP_RNG_SEED,
+				RNG_SEED_SIZE, &rng_seed);
+		if (ret)
+			goto out;
+		get_random_bytes(rng_seed, RNG_SEED_SIZE);
+	} else {
+		pr_notice("RNG is not initialised: omitting \"%s\" property\n",
+				FDT_PROP_RNG_SEED);
+	}
+
+	ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
+
+out:
+	if (ret) {
+		kvfree(fdt);
+		fdt = NULL;
+	}
+
+	return fdt;
+}
diff --git a/include/linux/of.h b/include/linux/of.h
index 4b27c9a27df3..d66c915df910 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -560,6 +560,11 @@ int of_map_id(struct device_node *np, u32 id,
 
 phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
 
+struct kimage;
+void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
+				   unsigned long initrd_load_addr,
+				   unsigned long initrd_len,
+				   const char *cmdline, size_t extra_fdt_size);
 #else /* CONFIG_OF */
 
 static inline void of_core_init(void)
