[linux-2.6-block.git] / drivers / firmware / efi / libstub / fdt.c

// 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);
	if (!efi_novamap)
		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;
}
Commit	Line	Data
4febfb8d	1	// SPDX-License-Identifier: GPL-2.0
263b4a30 RF	2	/*
	3	* FDT related Helper functions used by the EFI stub on multiple
	4	* architectures. This should be #included by the EFI stub
	5	* implementation files.
	6	*
	7	* Copyright 2013 Linaro Limited; author Roy Franz
263b4a30 RF	8	*/
263b4a30 RF	9
bd669475 AB	10	#include <linux/efi.h>
	11	#include <linux/libfdt.h>
	12	#include <asm/efi.h>
	13
f3cdfd23 AB	14	#include "efistub.h"
f3cdfd23 AB	15
ae8a442d SG	16	#define EFI_DT_ADDR_CELLS_DEFAULT 2
	17	#define EFI_DT_SIZE_CELLS_DEFAULT 2
	18
cd33a5c1	19	static void fdt_update_cell_size(void *fdt)
ae8a442d SG	20	{
	21	int offset;
	22
	23	offset = fdt_path_offset(fdt, "/");
	24	/* Set the #address-cells and #size-cells values for an empty tree */
	25
ac9aff8e IM	26	fdt_setprop_u32(fdt, offset, "#address-cells", EFI_DT_ADDR_CELLS_DEFAULT);
ac9aff8e IM	27	fdt_setprop_u32(fdt, offset, "#size-cells", EFI_DT_SIZE_CELLS_DEFAULT);
ae8a442d SG	28	}
ae8a442d SG	29
cd33a5c1	30	static efi_status_t update_fdt(void *orig_fdt, unsigned long orig_fdt_size,
f4dc7fff	31	void fdt, int new_fdt_size, char cmdline_ptr)
263b4a30	32	{
500899c2	33	int node, num_rsv;
263b4a30 RF	34	int status;
	35	u32 fdt_val32;
	36	u64 fdt_val64;
	37
ac9aff8e	38	/* Do some checks on provided FDT, if it exists: */
263b4a30 RF	39	if (orig_fdt) {
263b4a30 RF	40	if (fdt_check_header(orig_fdt)) {
793473c2	41	efi_err("Device Tree header not valid!\n");
263b4a30 RF	42	return EFI_LOAD_ERROR;
	43	}
	44	/*
	45	* We don't get the size of the FDT if we get if from a
ac9aff8e	46	* configuration table:
263b4a30 RF	47	*/
263b4a30 RF	48	if (orig_fdt_size && fdt_totalsize(orig_fdt) > orig_fdt_size) {
793473c2	49	efi_err("Truncated device tree! foo!\n");
263b4a30 RF	50	return EFI_LOAD_ERROR;
	51	}
	52	}
	53
ae8a442d	54	if (orig_fdt) {
263b4a30	55	status = fdt_open_into(orig_fdt, fdt, new_fdt_size);
ae8a442d	56	} else {
263b4a30	57	status = fdt_create_empty_tree(fdt, new_fdt_size);
ae8a442d SG	58	if (status == 0) {
ae8a442d SG	59	/*
ac9aff8e IM	60	* Any failure from the following function is
ac9aff8e IM	61	* non-critical:
ae8a442d	62	*/
cd33a5c1	63	fdt_update_cell_size(fdt);
ae8a442d SG	64	}
ae8a442d SG	65	}
263b4a30 RF	66
	67	if (status != 0)
	68	goto fdt_set_fail;
	69
0ceac9e0 MS	70	/*
	71	* Delete all memory reserve map entries. When booting via UEFI,
	72	* kernel will use the UEFI memory map to find reserved regions.
	73	*/
	74	num_rsv = fdt_num_mem_rsv(fdt);
	75	while (num_rsv-- > 0)
	76	fdt_del_mem_rsv(fdt, num_rsv);
	77
263b4a30 RF	78	node = fdt_subnode_offset(fdt, 0, "chosen");
	79	if (node < 0) {
	80	node = fdt_add_subnode(fdt, 0, "chosen");
	81	if (node < 0) {
ac9aff8e IM	82	/* 'node' is an error code when negative: */
ac9aff8e IM	83	status = node;
263b4a30 RF	84	goto fdt_set_fail;
	85	}
	86	}
	87
ac9aff8e	88	if (cmdline_ptr != NULL && strlen(cmdline_ptr) > 0) {
263b4a30 RF	89	status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr,
	90	strlen(cmdline_ptr) + 1);
	91	if (status)
	92	goto fdt_set_fail;
	93	}
	94
263b4a30 RF	95	/* Add FDT entries for EFI runtime services in chosen node. */
263b4a30 RF	96	node = fdt_subnode_offset(fdt, 0, "chosen");
ccc27ae7	97	fdt_val64 = cpu_to_fdt64((u64)(unsigned long)efi_system_table);
ac9aff8e IM	98
ac9aff8e IM	99	status = fdt_setprop_var(fdt, node, "linux,uefi-system-table", fdt_val64);
263b4a30 RF	100	if (status)
	101	goto fdt_set_fail;
	102
abfb7b68	103	fdt_val64 = U64_MAX; /* placeholder */
ac9aff8e IM	104
ac9aff8e IM	105	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-start", fdt_val64);
263b4a30 RF	106	if (status)
	107	goto fdt_set_fail;
	108
abfb7b68	109	fdt_val32 = U32_MAX; /* placeholder */
ac9aff8e IM	110
ac9aff8e IM	111	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-size", fdt_val32);
263b4a30 RF	112	if (status)
	113	goto fdt_set_fail;
	114
ac9aff8e	115	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32);
263b4a30 RF	116	if (status)
	117	goto fdt_set_fail;
	118
ac9aff8e	119	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-ver", fdt_val32);
263b4a30 RF	120	if (status)
	121	goto fdt_set_fail;
	122
d32de913	123	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
2b5fe07a AB	124	efi_status_t efi_status;
2b5fe07a AB	125
cd33a5c1	126	efi_status = efi_get_random_bytes(sizeof(fdt_val64),
2b5fe07a AB	127	(u8 *)&fdt_val64);
2b5fe07a AB	128	if (efi_status == EFI_SUCCESS) {
ac9aff8e	129	status = fdt_setprop_var(fdt, node, "kaslr-seed", fdt_val64);
2b5fe07a AB	130	if (status)
2b5fe07a AB	131	goto fdt_set_fail;
2b5fe07a AB	132	}
2b5fe07a AB	133	}
72a58a63	134
ac9aff8e	135	/* Shrink the FDT back to its minimum size: */
72a58a63 AB	136	fdt_pack(fdt);
72a58a63 AB	137
263b4a30 RF	138	return EFI_SUCCESS;
	139
	140	fdt_set_fail:
	141	if (status == -FDT_ERR_NOSPACE)
	142	return EFI_BUFFER_TOO_SMALL;
	143
	144	return EFI_LOAD_ERROR;
	145	}
	146
abfb7b68 AB	147	static efi_status_t update_fdt_memmap(void fdt, struct efi_boot_memmap map)
	148	{
	149	int node = fdt_path_offset(fdt, "/chosen");
	150	u64 fdt_val64;
	151	u32 fdt_val32;
	152	int err;
	153
	154	if (node < 0)
	155	return EFI_LOAD_ERROR;
	156
eab31265	157	fdt_val64 = cpu_to_fdt64((unsigned long)map->map);
ac9aff8e IM	158
ac9aff8e IM	159	err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-start", fdt_val64);
abfb7b68 AB	160	if (err)
	161	return EFI_LOAD_ERROR;
	162
eab31265	163	fdt_val32 = cpu_to_fdt32(map->map_size);
ac9aff8e IM	164
ac9aff8e IM	165	err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-size", fdt_val32);
abfb7b68 AB	166	if (err)
	167	return EFI_LOAD_ERROR;
	168
eab31265	169	fdt_val32 = cpu_to_fdt32(map->desc_size);
ac9aff8e IM	170
ac9aff8e IM	171	err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32);
abfb7b68 AB	172	if (err)
	173	return EFI_LOAD_ERROR;
	174
eab31265	175	fdt_val32 = cpu_to_fdt32(map->desc_ver);
ac9aff8e IM	176
ac9aff8e IM	177	err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-ver", fdt_val32);
abfb7b68 AB	178	if (err)
	179	return EFI_LOAD_ERROR;
	180
	181	return EFI_SUCCESS;
	182	}
	183
ed9cc156	184	struct exit_boot_struct {
eab31265	185	struct efi_boot_memmap *boot_memmap;
ac9aff8e	186	efi_memory_desc_t *runtime_map;
f80d2604	187	int runtime_entry_count;
ac9aff8e	188	void *new_fdt_addr;
ed9cc156 JH	189	};
ed9cc156 JH	190
eab31265	191	static efi_status_t exit_boot_func(struct efi_boot_memmap map, void priv)
ed9cc156 JH	192	{
ed9cc156 JH	193	struct exit_boot_struct *p = priv;
eab31265 AB	194
	195	p->boot_memmap = map;
	196
ed9cc156 JH	197	/*
	198	* Update the memory map with virtual addresses. The function will also
	199	* populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME
	200	* entries so that we can pass it straight to SetVirtualAddressMap()
	201	*/
eab31265	202	efi_get_virtmap(map->map, map->map_size, map->desc_size,
f80d2604	203	p->runtime_map, &p->runtime_entry_count);
ed9cc156	204
c8f325a5	205	return update_fdt_memmap(p->new_fdt_addr, map);
ed9cc156 JH	206	}
ed9cc156 JH	207
24d7c494	208	#ifndef MAX_FDT_SIZE
ac9aff8e	209	# define MAX_FDT_SIZE SZ_2M
24d7c494 AB	210	#endif
24d7c494 AB	211
263b4a30	212	/*
f4dc7fff AB	213	* Allocate memory for a new FDT, then add EFI and commandline related fields
	214	* to the FDT. This routine increases the FDT allocation size until the
	215	* allocated memory is large enough. EFI allocations are in EFI_PAGE_SIZE
	216	* granules, which are fixed at 4K bytes, so in most cases the first allocation
	217	* should succeed. EFI boot services are exited at the end of this function.
	218	* There must be no allocations between the get_memory_map() call and the
	219	* exit_boot_services() call, so the exiting of boot services is very tightly
	220	* tied to the creation of the FDT with the final memory map in it.
263b4a30	221	*/
4fc8e738	222	static
cd33a5c1	223	efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
4fc8e738	224	efi_loaded_image_t *image,
263b4a30	225	unsigned long *new_fdt_addr,
4fc8e738	226	char *cmdline_ptr)
263b4a30	227	{
eab31265	228	unsigned long desc_size;
263b4a30	229	u32 desc_ver;
263b4a30	230	efi_status_t status;
ed9cc156	231	struct exit_boot_struct priv;
4fc8e738 AB	232	unsigned long fdt_addr = 0;
4fc8e738 AB	233	unsigned long fdt_size = 0;
dadb57ab	234
f80d2604 AB	235	if (!efi_novamap) {
	236	status = efi_alloc_virtmap(&priv.runtime_map, &desc_size,
	237	&desc_ver);
	238	if (status != EFI_SUCCESS) {
	239	efi_err("Unable to retrieve UEFI memory map.\n");
	240	return status;
	241	}
f3cdfd23 AB	242	}
f3cdfd23 AB	243
4fc8e738 AB	244	/*
	245	* Unauthenticated device tree data is a security hazard, so ignore
	246	* 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure
	247	* boot is enabled if we can't determine its state.
	248	*/
	249	if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) \|\|
	250	efi_get_secureboot() != efi_secureboot_mode_disabled) {
	251	if (strstr(cmdline_ptr, "dtb="))
	252	efi_err("Ignoring DTB from command line.\n");
	253	} else {
	254	status = efi_load_dtb(image, &fdt_addr, &fdt_size);
	255
	256	if (status != EFI_SUCCESS && status != EFI_NOT_READY) {
	257	efi_err("Failed to load device tree!\n");
	258	goto fail;
	259	}
	260	}
	261
	262	if (fdt_addr) {
	263	efi_info("Using DTB from command line\n");
	264	} else {
	265	/* Look for a device tree configuration table entry. */
	266	fdt_addr = (uintptr_t)get_fdt(&fdt_size);
	267	if (fdt_addr)
	268	efi_info("Using DTB from configuration table\n");
	269	}
	270
	271	if (!fdt_addr)
	272	efi_info("Generating empty DTB\n");
	273
68c9cdf3	274	efi_info("Exiting boot services...\n");
263b4a30	275
54649911	276	status = efi_allocate_pages(MAX_FDT_SIZE, new_fdt_addr, ULONG_MAX);
24d7c494	277	if (status != EFI_SUCCESS) {
793473c2	278	efi_err("Unable to allocate memory for new device tree.\n");
24d7c494 AB	279	goto fail;
	280	}
	281
cd33a5c1	282	status = update_fdt((void *)fdt_addr, fdt_size,
f4dc7fff	283	(void )new_fdt_addr, MAX_FDT_SIZE, cmdline_ptr);
263b4a30	284
24d7c494	285	if (status != EFI_SUCCESS) {
793473c2	286	efi_err("Unable to construct new device tree.\n");
24d7c494	287	goto fail_free_new_fdt;
263b4a30 RF	288	}
263b4a30 RF	289
f80d2604	290	priv.new_fdt_addr = (void )new_fdt_addr;
ac9aff8e	291
eab31265	292	status = efi_exit_boot_services(handle, &priv, exit_boot_func);
263b4a30	293
f3cdfd23 AB	294	if (status == EFI_SUCCESS) {
f3cdfd23 AB	295	efi_set_virtual_address_map_t *svam;
263b4a30	296
980771f6	297	if (efi_novamap)
4e46c2a9 AB	298	return EFI_SUCCESS;
4e46c2a9 AB	299
f3cdfd23	300	/* Install the new virtual address map */
ccc27ae7	301	svam = efi_system_table->runtime->set_virtual_address_map;
f80d2604 AB	302	status = svam(priv.runtime_entry_count * desc_size, desc_size,
f80d2604 AB	303	desc_ver, priv.runtime_map);
f3cdfd23 AB	304
	305	/*
	306	* We are beyond the point of no return here, so if the call to
	307	* SetVirtualAddressMap() failed, we need to signal that to the
	308	* incoming kernel but proceed normally otherwise.
	309	*/
	310	if (status != EFI_SUCCESS) {
eab31265	311	efi_memory_desc_t *p;
f3cdfd23 AB	312	int l;
	313
	314	/*
	315	* Set the virtual address field of all
37926f96 AB	316	* EFI_MEMORY_RUNTIME entries to U64_MAX. This will
	317	* signal the incoming kernel that no virtual
	318	* translation has been installed.
f3cdfd23	319	*/
eab31265 AB	320	for (l = 0; l < priv.boot_memmap->map_size;
	321	l += priv.boot_memmap->desc_size) {
	322	p = (void *)priv.boot_memmap->map + l;
f3cdfd23 AB	323
f3cdfd23 AB	324	if (p->attribute & EFI_MEMORY_RUNTIME)
37926f96	325	p->virt_addr = U64_MAX;
f3cdfd23 AB	326	}
	327	}
	328	return EFI_SUCCESS;
	329	}
263b4a30	330
793473c2	331	efi_err("Exit boot services failed.\n");
263b4a30	332
263b4a30	333	fail_free_new_fdt:
cd33a5c1	334	efi_free(MAX_FDT_SIZE, *new_fdt_addr);
263b4a30 RF	335
263b4a30 RF	336	fail:
4fc8e738	337	efi_free(fdt_size, fdt_addr);
4b2543f7 HH	338	if (!efi_novamap)
4b2543f7 HH	339	efi_bs_call(free_pool, priv.runtime_map);
ac9aff8e	340
263b4a30 RF	341	return EFI_LOAD_ERROR;
	342	}
	343
4fc8e738 AB	344	efi_status_t efi_boot_kernel(void handle, efi_loaded_image_t image,
	345	unsigned long kernel_addr, char *cmdline_ptr)
	346	{
	347	unsigned long fdt_addr;
	348	efi_status_t status;
	349
	350	status = allocate_new_fdt_and_exit_boot(handle, image, &fdt_addr,
	351	cmdline_ptr);
	352	if (status != EFI_SUCCESS) {
	353	efi_err("Failed to update FDT and exit boot services\n");
	354	return status;
	355	}
	356
	357	if (IS_ENABLED(CONFIG_ARM))
	358	efi_handle_post_ebs_state();
	359
	360	efi_enter_kernel(kernel_addr, fdt_addr, fdt_totalsize((void *)fdt_addr));
	361	/* not reached */
	362	}
	363
cd33a5c1	364	void get_fdt(unsigned long fdt_size)
263b4a30	365	{
82d736ac	366	void *fdt;
263b4a30	367
cd33a5c1	368	fdt = get_efi_config_table(DEVICE_TREE_GUID);
263b4a30	369
82d736ac MG	370	if (!fdt)
82d736ac MG	371	return NULL;
8c25db0a	372
82d736ac	373	if (fdt_check_header(fdt) != 0) {
793473c2	374	efi_err("Invalid header detected on UEFI supplied FDT, ignoring ...\n");
82d736ac	375	return NULL;
6935b3c4	376	}
82d736ac MG	377	*fdt_size = fdt_totalsize(fdt);
82d736ac MG	378	return fdt;
263b4a30	379	}