drivers/firmware/efi/libstub/fdt.c - linux/kernel/git/torvalds/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * FDT related Helper functions used by the EFI stub on multiple
  * architectures. This should be #included by the EFI stub
  * implementation files.
  *
  * Copyright 2013 Linaro Limited; author Roy Franz
  */

 #include <linux/efi.h>
 #include <linux/libfdt.h>
 #include <asm/efi.h>

 #include "efistub.h"

 #define EFI_DT_ADDR_CELLS_DEFAULT 2
 #define EFI_DT_SIZE_CELLS_DEFAULT 2

 static void fdt_update_cell_size(void *fdt)
 {
 	int offset;

 	offset = fdt_path_offset(fdt, "/");
 	/* Set the #address-cells and #size-cells values for an empty tree */

 	fdt_setprop_u32(fdt, offset, "#address-cells", EFI_DT_ADDR_CELLS_DEFAULT);
 	fdt_setprop_u32(fdt, offset, "#size-cells",    EFI_DT_SIZE_CELLS_DEFAULT);
 }

 static efi_status_t update_fdt(void *orig_fdt, unsigned long orig_fdt_size,
 			       void *fdt, int new_fdt_size, char *cmdline_ptr)
 {
 	int node, num_rsv;
 	int status;
 	u32 fdt_val32;
 	u64 fdt_val64;

 	/* Do some checks on provided FDT, if it exists: */
 	if (orig_fdt) {
 		if (fdt_check_header(orig_fdt)) {
 			efi_err("Device Tree header not valid!\n");
 			return EFI_LOAD_ERROR;
 		}
 		/*
 		 * We don't get the size of the FDT if we get if from a
 		 * configuration table:
 		 */
 		if (orig_fdt_size && fdt_totalsize(orig_fdt) > orig_fdt_size) {
 			efi_err("Truncated device tree! foo!\n");
 			return EFI_LOAD_ERROR;
 		}
 	}

 	if (orig_fdt) {
 		status = fdt_open_into(orig_fdt, fdt, new_fdt_size);
 	} else {
 		status = fdt_create_empty_tree(fdt, new_fdt_size);
 		if (status == 0) {
 			/*
 			 * Any failure from the following function is
 			 * non-critical:
 			 */
 			fdt_update_cell_size(fdt);
 		}
 	}

 	if (status != 0)
 		goto fdt_set_fail;

 	/*
 	 * Delete all memory reserve map entries. When booting via UEFI,
 	 * kernel will use the UEFI memory map to find reserved regions.
 	 */
 	num_rsv = fdt_num_mem_rsv(fdt);
 	while (num_rsv-- > 0)
 		fdt_del_mem_rsv(fdt, num_rsv);

 	node = fdt_subnode_offset(fdt, 0, "chosen");
 	if (node < 0) {
 		node = fdt_add_subnode(fdt, 0, "chosen");
 		if (node < 0) {
 			/* 'node' is an error code when negative: */
 			status = node;
 			goto fdt_set_fail;
 		}
 	}

 	if (cmdline_ptr != NULL && strlen(cmdline_ptr) > 0) {
 		status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr,
 				     strlen(cmdline_ptr) + 1);
 		if (status)
 			goto fdt_set_fail;
 	}

 	/* Add FDT entries for EFI runtime services in chosen node. */
 	node = fdt_subnode_offset(fdt, 0, "chosen");
 	fdt_val64 = cpu_to_fdt64((u64)(unsigned long)efi_system_table);

 	status = fdt_setprop_var(fdt, node, "linux,uefi-system-table", fdt_val64);
 	if (status)
 		goto fdt_set_fail;

 	fdt_val64 = U64_MAX; /* placeholder */

 	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-start", fdt_val64);
 	if (status)
 		goto fdt_set_fail;

 	fdt_val32 = U32_MAX; /* placeholder */

 	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-size", fdt_val32);
 	if (status)
 		goto fdt_set_fail;

 	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32);
 	if (status)
 		goto fdt_set_fail;

 	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-ver", fdt_val32);
 	if (status)
 		goto fdt_set_fail;

 	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
 		efi_status_t efi_status;

 		efi_status = efi_get_random_bytes(sizeof(fdt_val64),
 						  (u8 *)&fdt_val64);
 		if (efi_status == EFI_SUCCESS) {
 			status = fdt_setprop_var(fdt, node, "kaslr-seed", fdt_val64);
 			if (status)
 				goto fdt_set_fail;
 		}
 	}

 	/* Shrink the FDT back to its minimum size: */
 	fdt_pack(fdt);

 	return EFI_SUCCESS;

 fdt_set_fail:
 	if (status == -FDT_ERR_NOSPACE)
 		return EFI_BUFFER_TOO_SMALL;

 	return EFI_LOAD_ERROR;
 }

 static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map)
 {
 	int node = fdt_path_offset(fdt, "/chosen");
 	u64 fdt_val64;
 	u32 fdt_val32;
 	int err;

 	if (node < 0)
 		return EFI_LOAD_ERROR;

 	fdt_val64 = cpu_to_fdt64((unsigned long)map->map);

 	err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-start", fdt_val64);
 	if (err)
 		return EFI_LOAD_ERROR;

 	fdt_val32 = cpu_to_fdt32(map->map_size);

 	err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-size", fdt_val32);
 	if (err)
 		return EFI_LOAD_ERROR;

 	fdt_val32 = cpu_to_fdt32(map->desc_size);

 	err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32);
 	if (err)
 		return EFI_LOAD_ERROR;

 	fdt_val32 = cpu_to_fdt32(map->desc_ver);

 	err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-ver", fdt_val32);
 	if (err)
 		return EFI_LOAD_ERROR;

 	return EFI_SUCCESS;
 }

 struct exit_boot_struct {
 	struct efi_boot_memmap	*boot_memmap;
 	efi_memory_desc_t	*runtime_map;
 	int			runtime_entry_count;
 	void			*new_fdt_addr;
 };

 static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv)
 {
 	struct exit_boot_struct *p = priv;

 	p->boot_memmap = map;

 	/*
 	 * Update the memory map with virtual addresses. The function will also
 	 * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME
 	 * entries so that we can pass it straight to SetVirtualAddressMap()
 	 */
 	efi_get_virtmap(map->map, map->map_size, map->desc_size,
 			p->runtime_map, &p->runtime_entry_count);

 	return update_fdt_memmap(p->new_fdt_addr, map);
 }

 #ifndef MAX_FDT_SIZE
 # define MAX_FDT_SIZE SZ_2M
 #endif

 /*
  * Allocate memory for a new FDT, then add EFI and commandline related fields
  * to the FDT.  This routine increases the FDT allocation size until the
  * allocated memory is large enough.  EFI allocations are in EFI_PAGE_SIZE
  * granules, which are fixed at 4K bytes, so in most cases the first allocation
  * should succeed.  EFI boot services are exited at the end of this function.
  * There must be no allocations between the get_memory_map() call and the
  * exit_boot_services() call, so the exiting of boot services is very tightly
  * tied to the creation of the FDT with the final memory map in it.
  */
 static
 efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
 					    efi_loaded_image_t *image,
 					    unsigned long *new_fdt_addr,
 					    char *cmdline_ptr)
 {
 	unsigned long desc_size;
 	u32 desc_ver;
 	efi_status_t status;
 	struct exit_boot_struct priv;
 	unsigned long fdt_addr = 0;
 	unsigned long fdt_size = 0;

 	if (!efi_novamap) {
 		status = efi_alloc_virtmap(&priv.runtime_map, &desc_size,
 					   &desc_ver);
 		if (status != EFI_SUCCESS) {
 			efi_err("Unable to retrieve UEFI memory map.\n");
 			return status;
 		}
 	}

 	/*
 	 * Unauthenticated device tree data is a security hazard, so ignore
 	 * 'dtb=' unless UEFI Secure Boot is disabled.  We assume that secure
 	 * boot is enabled if we can't determine its state.
 	 */
 	if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
 	    efi_get_secureboot() != efi_secureboot_mode_disabled) {
 		if (strstr(cmdline_ptr, "dtb="))
 			efi_err("Ignoring DTB from command line.\n");
 	} else {
 		status = efi_load_dtb(image, &fdt_addr, &fdt_size);

 		if (status != EFI_SUCCESS && status != EFI_NOT_READY) {
 			efi_err("Failed to load device tree!\n");
 			goto fail;
 		}
 	}

 	if (fdt_addr) {
 		efi_info("Using DTB from command line\n");
 	} else {
 		/* Look for a device tree configuration table entry. */
 		fdt_addr = (uintptr_t)get_fdt(&fdt_size);
 		if (fdt_addr)
 			efi_info("Using DTB from configuration table\n");
 	}

 	if (!fdt_addr)
 		efi_info("Generating empty DTB\n");

 	efi_info("Exiting boot services...\n");

 	status = efi_allocate_pages(MAX_FDT_SIZE, new_fdt_addr, ULONG_MAX);
 	if (status != EFI_SUCCESS) {
 		efi_err("Unable to allocate memory for new device tree.\n");
 		goto fail;
 	}

 	status = update_fdt((void *)fdt_addr, fdt_size,
 			    (void *)*new_fdt_addr, MAX_FDT_SIZE, cmdline_ptr);

 	if (status != EFI_SUCCESS) {
 		efi_err("Unable to construct new device tree.\n");
 		goto fail_free_new_fdt;
 	}

 	priv.new_fdt_addr = (void *)*new_fdt_addr;

 	status = efi_exit_boot_services(handle, &priv, exit_boot_func);

 	if (status == EFI_SUCCESS) {
 		efi_set_virtual_address_map_t *svam;

 		if (efi_novamap)
 			return EFI_SUCCESS;

 		/* Install the new virtual address map */
 		svam = efi_system_table->runtime->set_virtual_address_map;
 		status = svam(priv.runtime_entry_count * desc_size, desc_size,
 			      desc_ver, priv.runtime_map);

 		/*
 		 * We are beyond the point of no return here, so if the call to
 		 * SetVirtualAddressMap() failed, we need to signal that to the
 		 * incoming kernel but proceed normally otherwise.
 		 */
 		if (status != EFI_SUCCESS) {
 			efi_memory_desc_t *p;
 			int l;

 			/*
 			 * Set the virtual address field of all
 			 * EFI_MEMORY_RUNTIME entries to U64_MAX. This will
 			 * signal the incoming kernel that no virtual
 			 * translation has been installed.
 			 */
 			for (l = 0; l < priv.boot_memmap->map_size;
 			     l += priv.boot_memmap->desc_size) {
 				p = (void *)priv.boot_memmap->map + l;

 				if (p->attribute & EFI_MEMORY_RUNTIME)
 					p->virt_addr = U64_MAX;
 			}
 		}
 		return EFI_SUCCESS;
 	}

 	efi_err("Exit boot services failed.\n");

 fail_free_new_fdt:
 	efi_free(MAX_FDT_SIZE, *new_fdt_addr);

 fail:
 	efi_free(fdt_size, fdt_addr);

 	efi_bs_call(free_pool, priv.runtime_map);

 	return EFI_LOAD_ERROR;
 }

 efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image,
 			     unsigned long kernel_addr, char *cmdline_ptr)
 {
 	unsigned long fdt_addr;
 	efi_status_t status;

 	status = allocate_new_fdt_and_exit_boot(handle, image, &fdt_addr,
 						cmdline_ptr);
 	if (status != EFI_SUCCESS) {
 		efi_err("Failed to update FDT and exit boot services\n");
 		return status;
 	}

 	if (IS_ENABLED(CONFIG_ARM))
 		efi_handle_post_ebs_state();

 	efi_enter_kernel(kernel_addr, fdt_addr, fdt_totalsize((void *)fdt_addr));
 	/* not reached */
 }

 void *get_fdt(unsigned long *fdt_size)
 {
 	void *fdt;

 	fdt = get_efi_config_table(DEVICE_TREE_GUID);

 	if (!fdt)
 		return NULL;

 	if (fdt_check_header(fdt) != 0) {
 		efi_err("Invalid header detected on UEFI supplied FDT, ignoring ...\n");
 		return NULL;
 	}
 	*fdt_size = fdt_totalsize(fdt);
 	return fdt;
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* FDT related Helper functions used by the EFI stub on multiple
	* architectures. This should be #included by the EFI stub
	* implementation files.
	*
	* Copyright 2013 Linaro Limited; author Roy Franz
	*/

	#include <linux/efi.h>
	#include <linux/libfdt.h>
	#include <asm/efi.h>

	#include "efistub.h"

	#define EFI_DT_ADDR_CELLS_DEFAULT 2
	#define EFI_DT_SIZE_CELLS_DEFAULT 2

	static void fdt_update_cell_size(void *fdt)
	{
	int offset;

	offset = fdt_path_offset(fdt, "/");
	/* Set the #address-cells and #size-cells values for an empty tree */

	fdt_setprop_u32(fdt, offset, "#address-cells", EFI_DT_ADDR_CELLS_DEFAULT);
	fdt_setprop_u32(fdt, offset, "#size-cells", EFI_DT_SIZE_CELLS_DEFAULT);
	}

	static efi_status_t update_fdt(void *orig_fdt, unsigned long orig_fdt_size,
	void fdt, int new_fdt_size, char cmdline_ptr)
	{
	int node, num_rsv;
	int status;
	u32 fdt_val32;
	u64 fdt_val64;

	/* Do some checks on provided FDT, if it exists: */
	if (orig_fdt) {
	if (fdt_check_header(orig_fdt)) {
	efi_err("Device Tree header not valid!\n");
	return EFI_LOAD_ERROR;
	}
	/*
	* We don't get the size of the FDT if we get if from a
	* configuration table:
	*/
	if (orig_fdt_size && fdt_totalsize(orig_fdt) > orig_fdt_size) {
	efi_err("Truncated device tree! foo!\n");
	return EFI_LOAD_ERROR;
	}
	}

	if (orig_fdt) {
	status = fdt_open_into(orig_fdt, fdt, new_fdt_size);
	} else {
	status = fdt_create_empty_tree(fdt, new_fdt_size);
	if (status == 0) {
	/*
	* Any failure from the following function is
	* non-critical:
	*/
	fdt_update_cell_size(fdt);
	}
	}

	if (status != 0)
	goto fdt_set_fail;

	/*
	* Delete all memory reserve map entries. When booting via UEFI,
	* kernel will use the UEFI memory map to find reserved regions.
	*/
	num_rsv = fdt_num_mem_rsv(fdt);
	while (num_rsv-- > 0)
	fdt_del_mem_rsv(fdt, num_rsv);

	node = fdt_subnode_offset(fdt, 0, "chosen");
	if (node < 0) {
	node = fdt_add_subnode(fdt, 0, "chosen");
	if (node < 0) {
	/* 'node' is an error code when negative: */
	status = node;
	goto fdt_set_fail;
	}
	}

	if (cmdline_ptr != NULL && strlen(cmdline_ptr) > 0) {
	status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr,
	strlen(cmdline_ptr) + 1);
	if (status)
	goto fdt_set_fail;
	}

	/* Add FDT entries for EFI runtime services in chosen node. */
	node = fdt_subnode_offset(fdt, 0, "chosen");
	fdt_val64 = cpu_to_fdt64((u64)(unsigned long)efi_system_table);

	status = fdt_setprop_var(fdt, node, "linux,uefi-system-table", fdt_val64);
	if (status)
	goto fdt_set_fail;

	fdt_val64 = U64_MAX; /* placeholder */

	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-start", fdt_val64);
	if (status)
	goto fdt_set_fail;

	fdt_val32 = U32_MAX; /* placeholder */

	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-size", fdt_val32);
	if (status)
	goto fdt_set_fail;

	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32);
	if (status)
	goto fdt_set_fail;

	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-ver", fdt_val32);
	if (status)
	goto fdt_set_fail;

	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
	efi_status_t efi_status;

	efi_status = efi_get_random_bytes(sizeof(fdt_val64),
	(u8 *)&fdt_val64);
	if (efi_status == EFI_SUCCESS) {
	status = fdt_setprop_var(fdt, node, "kaslr-seed", fdt_val64);
	if (status)
	goto fdt_set_fail;
	}
	}

	/* Shrink the FDT back to its minimum size: */
	fdt_pack(fdt);

	return EFI_SUCCESS;

	fdt_set_fail:
	if (status == -FDT_ERR_NOSPACE)
	return EFI_BUFFER_TOO_SMALL;

	return EFI_LOAD_ERROR;
	}

	static efi_status_t update_fdt_memmap(void fdt, struct efi_boot_memmap map)
	{
	int node = fdt_path_offset(fdt, "/chosen");
	u64 fdt_val64;
	u32 fdt_val32;
	int err;

	if (node < 0)
	return EFI_LOAD_ERROR;

	fdt_val64 = cpu_to_fdt64((unsigned long)map->map);

	err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-start", fdt_val64);
	if (err)
	return EFI_LOAD_ERROR;

	fdt_val32 = cpu_to_fdt32(map->map_size);

	err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-size", fdt_val32);
	if (err)
	return EFI_LOAD_ERROR;

	fdt_val32 = cpu_to_fdt32(map->desc_size);

	err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32);
	if (err)
	return EFI_LOAD_ERROR;

	fdt_val32 = cpu_to_fdt32(map->desc_ver);

	err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-ver", fdt_val32);
	if (err)
	return EFI_LOAD_ERROR;

	return EFI_SUCCESS;
	}

	struct exit_boot_struct {
	struct efi_boot_memmap *boot_memmap;
	efi_memory_desc_t *runtime_map;
	int runtime_entry_count;
	void *new_fdt_addr;
	};

	static efi_status_t exit_boot_func(struct efi_boot_memmap map, void priv)
	{
	struct exit_boot_struct *p = priv;

	p->boot_memmap = map;

	/*
	* Update the memory map with virtual addresses. The function will also
	* populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME
	* entries so that we can pass it straight to SetVirtualAddressMap()
	*/
	efi_get_virtmap(map->map, map->map_size, map->desc_size,
	p->runtime_map, &p->runtime_entry_count);

	return update_fdt_memmap(p->new_fdt_addr, map);
	}

	#ifndef MAX_FDT_SIZE
	# define MAX_FDT_SIZE SZ_2M
	#endif

	/*
	* Allocate memory for a new FDT, then add EFI and commandline related fields
	* to the FDT. This routine increases the FDT allocation size until the
	* allocated memory is large enough. EFI allocations are in EFI_PAGE_SIZE
	* granules, which are fixed at 4K bytes, so in most cases the first allocation
	* should succeed. EFI boot services are exited at the end of this function.
	* There must be no allocations between the get_memory_map() call and the
	* exit_boot_services() call, so the exiting of boot services is very tightly
	* tied to the creation of the FDT with the final memory map in it.
	*/
	static
	efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
	efi_loaded_image_t *image,
	unsigned long *new_fdt_addr,
	char *cmdline_ptr)
	{
	unsigned long desc_size;
	u32 desc_ver;
	efi_status_t status;
	struct exit_boot_struct priv;
	unsigned long fdt_addr = 0;
	unsigned long fdt_size = 0;

	if (!efi_novamap) {
	status = efi_alloc_virtmap(&priv.runtime_map, &desc_size,
	&desc_ver);
	if (status != EFI_SUCCESS) {
	efi_err("Unable to retrieve UEFI memory map.\n");
	return status;
	}
	}

	/*
	* Unauthenticated device tree data is a security hazard, so ignore
	* 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure
	* boot is enabled if we can't determine its state.
	*/
	if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) \|\|
	efi_get_secureboot() != efi_secureboot_mode_disabled) {
	if (strstr(cmdline_ptr, "dtb="))
	efi_err("Ignoring DTB from command line.\n");
	} else {
	status = efi_load_dtb(image, &fdt_addr, &fdt_size);

	if (status != EFI_SUCCESS && status != EFI_NOT_READY) {
	efi_err("Failed to load device tree!\n");
	goto fail;
	}
	}

	if (fdt_addr) {
	efi_info("Using DTB from command line\n");
	} else {
	/* Look for a device tree configuration table entry. */
	fdt_addr = (uintptr_t)get_fdt(&fdt_size);
	if (fdt_addr)
	efi_info("Using DTB from configuration table\n");
	}

	if (!fdt_addr)
	efi_info("Generating empty DTB\n");

	efi_info("Exiting boot services...\n");

	status = efi_allocate_pages(MAX_FDT_SIZE, new_fdt_addr, ULONG_MAX);
	if (status != EFI_SUCCESS) {
	efi_err("Unable to allocate memory for new device tree.\n");
	goto fail;
	}

	status = update_fdt((void *)fdt_addr, fdt_size,
	(void )new_fdt_addr, MAX_FDT_SIZE, cmdline_ptr);

	if (status != EFI_SUCCESS) {
	efi_err("Unable to construct new device tree.\n");
	goto fail_free_new_fdt;
	}

	priv.new_fdt_addr = (void )new_fdt_addr;

	status = efi_exit_boot_services(handle, &priv, exit_boot_func);

	if (status == EFI_SUCCESS) {
	efi_set_virtual_address_map_t *svam;

	if (efi_novamap)
	return EFI_SUCCESS;

	/* Install the new virtual address map */
	svam = efi_system_table->runtime->set_virtual_address_map;
	status = svam(priv.runtime_entry_count * desc_size, desc_size,
	desc_ver, priv.runtime_map);

	/*
	* We are beyond the point of no return here, so if the call to
	* SetVirtualAddressMap() failed, we need to signal that to the
	* incoming kernel but proceed normally otherwise.
	*/
	if (status != EFI_SUCCESS) {
	efi_memory_desc_t *p;
	int l;

	/*
	* Set the virtual address field of all
	* EFI_MEMORY_RUNTIME entries to U64_MAX. This will
	* signal the incoming kernel that no virtual
	* translation has been installed.
	*/
	for (l = 0; l < priv.boot_memmap->map_size;
	l += priv.boot_memmap->desc_size) {
	p = (void *)priv.boot_memmap->map + l;

	if (p->attribute & EFI_MEMORY_RUNTIME)
	p->virt_addr = U64_MAX;
	}
	}
	return EFI_SUCCESS;
	}

	efi_err("Exit boot services failed.\n");

	fail_free_new_fdt:
	efi_free(MAX_FDT_SIZE, *new_fdt_addr);

	fail:
	efi_free(fdt_size, fdt_addr);

	efi_bs_call(free_pool, priv.runtime_map);

	return EFI_LOAD_ERROR;
	}

	efi_status_t efi_boot_kernel(void handle, efi_loaded_image_t image,
	unsigned long kernel_addr, char *cmdline_ptr)
	{
	unsigned long fdt_addr;
	efi_status_t status;

	status = allocate_new_fdt_and_exit_boot(handle, image, &fdt_addr,
	cmdline_ptr);
	if (status != EFI_SUCCESS) {
	efi_err("Failed to update FDT and exit boot services\n");
	return status;
	}

	if (IS_ENABLED(CONFIG_ARM))
	efi_handle_post_ebs_state();

	efi_enter_kernel(kernel_addr, fdt_addr, fdt_totalsize((void *)fdt_addr));
	/* not reached */
	}

	void get_fdt(unsigned long fdt_size)
	{
	void *fdt;

	fdt = get_efi_config_table(DEVICE_TREE_GUID);

	if (!fdt)
	return NULL;

	if (fdt_check_header(fdt) != 0) {
	efi_err("Invalid header detected on UEFI supplied FDT, ignoring ...\n");
	return NULL;
	}
	*fdt_size = fdt_totalsize(fdt);
	return fdt;
	}