efi_boottime.c

/*
 *  EFI application boot time services
 *
 *  Copyright (c) 2016 Alexander Graf
 *
 *  SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <efi_loader.h>
#include <environment.h>
#include <malloc.h>
#include <asm/global_data.h>
#include <libfdt_env.h>
#include <u-boot/crc.h>
#include <bootm.h>
#include <inttypes.h>
#include <watchdog.h>

DECLARE_GLOBAL_DATA_PTR;

/* Task priority level */
static UINTN efi_tpl = TPL_APPLICATION;

/* This list contains all the EFI objects our payload has access to */
LIST_HEAD(efi_obj_list);

/*
 * If we're running on nasty systems (32bit ARM booting into non-EFI Linux)
 * we need to do trickery with caches. Since we don't want to break the EFI
 * aware boot path, only apply hacks when loading exiting directly (breaking
 * direct Linux EFI booting along the way - oh well).
 */
static bool efi_is_direct_boot = true;

/*
 * EFI can pass arbitrary additional "tables" containing vendor specific
 * information to the payload. One such table is the FDT table which contains
 * a pointer to a flattened device tree blob.
 *
 * In most cases we want to pass an FDT to the payload, so reserve one slot of
 * config table space for it. The pointer gets populated by do_bootefi_exec().
 */
static struct efi_configuration_table __efi_runtime_data efi_conf_table[2];

#ifdef CONFIG_ARM
/*
 * The "gd" pointer lives in a register on ARM and AArch64 that we declare
 * fixed when compiling U-Boot. However, the payload does not know about that
 * restriction so we need to manually swap its and our view of that register on
 * EFI callback entry/exit.
 */
static volatile void *efi_gd, *app_gd;
#endif

static int entry_count;
static int nesting_level;

/* Called on every callback entry */
int __efi_entry_check(void)
{
	int ret = entry_count++ == 0;
#ifdef CONFIG_ARM
	assert(efi_gd);
	app_gd = gd;
	gd = efi_gd;
#endif
	return ret;
}

/* Called on every callback exit */
int __efi_exit_check(void)
{
	int ret = --entry_count == 0;
#ifdef CONFIG_ARM
	gd = app_gd;
#endif
	return ret;
}

/* Called from do_bootefi_exec() */
void efi_save_gd(void)
{
#ifdef CONFIG_ARM
	efi_gd = gd;
#endif
}

/*
 * Special case handler for error/abort that just forces things back
 * to u-boot world so we can dump out an abort msg, without any care
 * about returning back to UEFI world.
 */
void efi_restore_gd(void)
{
#ifdef CONFIG_ARM
	/* Only restore if we're already in EFI context */
	if (!efi_gd)
		return;
	gd = efi_gd;
#endif
}

/*
 * Two spaces per indent level, maxing out at 10.. which ought to be
 * enough for anyone ;-)
 */
static const char *indent_string(int level)
{
	const char *indent = "                    ";
	const int max = strlen(indent);
	level = min(max, level * 2);
	return &indent[max - level];
}

const char *__efi_nesting(void)
{
	return indent_string(nesting_level);
}

const char *__efi_nesting_inc(void)
{
	return indent_string(nesting_level++);
}

const char *__efi_nesting_dec(void)
{
	return indent_string(--nesting_level);
}

/* Low 32 bit */
#define EFI_LOW32(a) (a & 0xFFFFFFFFULL)
/* High 32 bit */
#define EFI_HIGH32(a) (a >> 32)

/*
 * 64bit division by 10 implemented as multiplication by 1 / 10
 *
 * Decimals of one tenth: 0x1 / 0xA = 0x0.19999...
 */
#define EFI_TENTH 0x199999999999999A
static u64 efi_div10(u64 a)
{
	u64 prod;
	u64 rem;
	u64 ret;

	ret  = EFI_HIGH32(a) * EFI_HIGH32(EFI_TENTH);
	prod = EFI_HIGH32(a) * EFI_LOW32(EFI_TENTH);
	rem  = EFI_LOW32(prod);
	ret += EFI_HIGH32(prod);
	prod = EFI_LOW32(a) * EFI_HIGH32(EFI_TENTH);
	rem += EFI_LOW32(prod);
	ret += EFI_HIGH32(prod);
	prod = EFI_LOW32(a) * EFI_LOW32(EFI_TENTH);
	rem += EFI_HIGH32(prod);
	ret += EFI_HIGH32(rem);
	/* Round to nearest integer */
	if (rem >= (1 << 31))
		++ret;
	return ret;
}

void efi_signal_event(struct efi_event *event)
{
	if (event->notify_function) {
		event->queued = 1;
		/* Check TPL */
		if (efi_tpl >= event->notify_tpl)
			return;
		EFI_CALL_VOID(event->notify_function(event,
						     event->notify_context));
	}
	event->queued = 0;
}

static efi_status_t efi_unsupported(const char *funcname)
{
	debug("EFI: App called into unimplemented function %s\n", funcname);
	return EFI_EXIT(EFI_UNSUPPORTED);
}

static unsigned long EFIAPI efi_raise_tpl(UINTN new_tpl)
{
	UINTN old_tpl = efi_tpl;

	EFI_ENTRY("0x%zx", new_tpl);

	if (new_tpl < efi_tpl)
		debug("WARNING: new_tpl < current_tpl in %s\n", __func__);
	efi_tpl = new_tpl;
	if (efi_tpl > TPL_HIGH_LEVEL)
		efi_tpl = TPL_HIGH_LEVEL;

	EFI_EXIT(EFI_SUCCESS);
	return old_tpl;
}

static void EFIAPI efi_restore_tpl(UINTN old_tpl)
{
	EFI_ENTRY("0x%zx", old_tpl);

	if (old_tpl > efi_tpl)
		debug("WARNING: old_tpl > current_tpl in %s\n", __func__);
	efi_tpl = old_tpl;
	if (efi_tpl > TPL_HIGH_LEVEL)
		efi_tpl = TPL_HIGH_LEVEL;

	EFI_EXIT(EFI_SUCCESS);
}

static efi_status_t EFIAPI efi_allocate_pages_ext(int type, int memory_type,
						  unsigned long pages,
						  uint64_t *memory)
{
	efi_status_t r;

	EFI_ENTRY("%d, %d, 0x%lx, %p", type, memory_type, pages, memory);
	r = efi_allocate_pages(type, memory_type, pages, memory);
	return EFI_EXIT(r);
}

static efi_status_t EFIAPI efi_free_pages_ext(uint64_t memory,
					      unsigned long pages)
{
	efi_status_t r;

	EFI_ENTRY("%"PRIx64", 0x%lx", memory, pages);
	r = efi_free_pages(memory, pages);
	return EFI_EXIT(r);
}

static efi_status_t EFIAPI efi_get_memory_map_ext(
					unsigned long *memory_map_size,
					struct efi_mem_desc *memory_map,
					unsigned long *map_key,
					unsigned long *descriptor_size,
					uint32_t *descriptor_version)
{
	efi_status_t r;

	EFI_ENTRY("%p, %p, %p, %p, %p", memory_map_size, memory_map,
		  map_key, descriptor_size, descriptor_version);
	r = efi_get_memory_map(memory_map_size, memory_map, map_key,
			       descriptor_size, descriptor_version);
	return EFI_EXIT(r);
}

static efi_status_t EFIAPI efi_allocate_pool_ext(int pool_type,
						 unsigned long size,
						 void **buffer)
{
	efi_status_t r;

	EFI_ENTRY("%d, %ld, %p", pool_type, size, buffer);
	r = efi_allocate_pool(pool_type, size, buffer);
	return EFI_EXIT(r);
}

static efi_status_t EFIAPI efi_free_pool_ext(void *buffer)
{
	efi_status_t r;

	EFI_ENTRY("%p", buffer);
	r = efi_free_pool(buffer);
	return EFI_EXIT(r);
}

static efi_status_t efi_create_handle(void **handle)
{
	struct efi_object *obj;
	efi_status_t r;

	r = efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES,
			      sizeof(struct efi_object),
			      (void **)&obj);
	if (r != EFI_SUCCESS)
		return r;
	memset(obj, 0, sizeof(struct efi_object));
	obj->handle = obj;
	list_add_tail(&obj->link, &efi_obj_list);
	*handle = obj;
	return r;
}

/*
 * Our event capabilities are very limited. Only a small limited
 * number of events is allowed to coexist.
 */
static struct efi_event efi_events[16];

efi_status_t efi_create_event(uint32_t type, UINTN notify_tpl,
			      void (EFIAPI *notify_function) (
					struct efi_event *event,
					void *context),
			      void *notify_context, struct efi_event **event)
{
	int i;

	if (event == NULL)
		return EFI_INVALID_PARAMETER;

	if ((type & EVT_NOTIFY_SIGNAL) && (type & EVT_NOTIFY_WAIT))
		return EFI_INVALID_PARAMETER;

	if ((type & (EVT_NOTIFY_SIGNAL|EVT_NOTIFY_WAIT)) &&
	    notify_function == NULL)
		return EFI_INVALID_PARAMETER;

	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
		if (efi_events[i].type)
			continue;
		efi_events[i].type = type;
		efi_events[i].notify_tpl = notify_tpl;
		efi_events[i].notify_function = notify_function;
		efi_events[i].notify_context = notify_context;
		/* Disable timers on bootup */
		efi_events[i].trigger_next = -1ULL;
		efi_events[i].queued = 0;
		efi_events[i].signaled = 0;
		*event = &efi_events[i];
		return EFI_SUCCESS;
	}
	return EFI_OUT_OF_RESOURCES;
}

static efi_status_t EFIAPI efi_create_event_ext(
			uint32_t type, UINTN notify_tpl,
			void (EFIAPI *notify_function) (
					struct efi_event *event,
					void *context),
			void *notify_context, struct efi_event **event)
{
	EFI_ENTRY("%d, 0x%zx, %p, %p", type, notify_tpl, notify_function,
		  notify_context);
	return EFI_EXIT(efi_create_event(type, notify_tpl, notify_function,
					 notify_context, event));
}


/*
 * Our timers have to work without interrupts, so we check whenever keyboard
 * input or disk accesses happen if enough time elapsed for it to fire.
 */
void efi_timer_check(void)
{
	int i;
	u64 now = timer_get_us();

	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
		if (!efi_events[i].type)
			continue;
		if (efi_events[i].queued)
			efi_signal_event(&efi_events[i]);
		if (!(efi_events[i].type & EVT_TIMER) ||
		    now < efi_events[i].trigger_next)
			continue;
		switch (efi_events[i].trigger_type) {
		case EFI_TIMER_RELATIVE:
			efi_events[i].trigger_type = EFI_TIMER_STOP;
			break;
		case EFI_TIMER_PERIODIC:
			efi_events[i].trigger_next +=
				efi_events[i].trigger_time;
			break;
		default:
			continue;
		}
		efi_events[i].signaled = 1;
		efi_signal_event(&efi_events[i]);
	}
	WATCHDOG_RESET();
}

efi_status_t efi_set_timer(struct efi_event *event, enum efi_timer_delay type,
			   uint64_t trigger_time)
{
	int i;

	/*
	 * The parameter defines a multiple of 100ns.
	 * We use multiples of 1000ns. So divide by 10.
	 */
	trigger_time = efi_div10(trigger_time);

	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
		if (event != &efi_events[i])
			continue;

		if (!(event->type & EVT_TIMER))
			break;
		switch (type) {
		case EFI_TIMER_STOP:
			event->trigger_next = -1ULL;
			break;
		case EFI_TIMER_PERIODIC:
		case EFI_TIMER_RELATIVE:
			event->trigger_next =
				timer_get_us() + trigger_time;
			break;
		default:
			return EFI_INVALID_PARAMETER;
		}
		event->trigger_type = type;
		event->trigger_time = trigger_time;
		event->signaled = 0;
		return EFI_SUCCESS;
	}
	return EFI_INVALID_PARAMETER;
}

static efi_status_t EFIAPI efi_set_timer_ext(struct efi_event *event,
					     enum efi_timer_delay type,
					     uint64_t trigger_time)
{
	EFI_ENTRY("%p, %d, %"PRIx64, event, type, trigger_time);
	return EFI_EXIT(efi_set_timer(event, type, trigger_time));
}

static efi_status_t EFIAPI efi_wait_for_event(unsigned long num_events,
					      struct efi_event **event,
					      unsigned long *index)
{
	int i, j;

	EFI_ENTRY("%ld, %p, %p", num_events, event, index);

	/* Check parameters */
	if (!num_events || !event)
		return EFI_EXIT(EFI_INVALID_PARAMETER);
	/* Check TPL */
	if (efi_tpl != TPL_APPLICATION)
		return EFI_EXIT(EFI_UNSUPPORTED);
	for (i = 0; i < num_events; ++i) {
		for (j = 0; j < ARRAY_SIZE(efi_events); ++j) {
			if (event[i] == &efi_events[j])
				goto known_event;
		}
		return EFI_EXIT(EFI_INVALID_PARAMETER);
known_event:
		if (!event[i]->type || event[i]->type & EVT_NOTIFY_SIGNAL)
			return EFI_EXIT(EFI_INVALID_PARAMETER);
		if (!event[i]->signaled)
			efi_signal_event(event[i]);
	}

	/* Wait for signal */
	for (;;) {
		for (i = 0; i < num_events; ++i) {
			if (event[i]->signaled)
				goto out;
		}
		/* Allow events to occur. */
		efi_timer_check();
	}

out:
	/*
	 * Reset the signal which is passed to the caller to allow periodic
	 * events to occur.
	 */
	event[i]->signaled = 0;
	if (index)
		*index = i;

	return EFI_EXIT(EFI_SUCCESS);
}

static efi_status_t EFIAPI efi_signal_event_ext(struct efi_event *event)
{
	int i;

	EFI_ENTRY("%p", event);
	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
		if (event != &efi_events[i])
			continue;
		if (event->signaled)
			break;
		event->signaled = 1;
		if (event->type & EVT_NOTIFY_SIGNAL)
			efi_signal_event(event);
		break;
	}
	return EFI_EXIT(EFI_SUCCESS);
}

static efi_status_t EFIAPI efi_close_event(struct efi_event *event)
{
	int i;

	EFI_ENTRY("%p", event);
	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
		if (event == &efi_events[i]) {
			event->type = 0;
			event->trigger_next = -1ULL;
			event->queued = 0;
			event->signaled = 0;
			return EFI_EXIT(EFI_SUCCESS);
		}
	}
	return EFI_EXIT(EFI_INVALID_PARAMETER);
}

static efi_status_t EFIAPI efi_check_event(struct efi_event *event)
{
	int i;

	EFI_ENTRY("%p", event);
	efi_timer_check();
	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
		if (event != &efi_events[i])
			continue;
		if (!event->type || event->type & EVT_NOTIFY_SIGNAL)
			break;
		if (!event->signaled)
			efi_signal_event(event);
		if (event->signaled)
			return EFI_EXIT(EFI_SUCCESS);
		return EFI_EXIT(EFI_NOT_READY);
	}
	return EFI_EXIT(EFI_INVALID_PARAMETER);
}

static efi_status_t EFIAPI efi_install_protocol_interface(void **handle,
			efi_guid_t *protocol, int protocol_interface_type,
			void *protocol_interface)
{
	struct list_head *lhandle;
	int i;
	efi_status_t r;

	if (!handle || !protocol ||
	    protocol_interface_type != EFI_NATIVE_INTERFACE) {
		r = EFI_INVALID_PARAMETER;
		goto out;
	}

	/* Create new handle if requested. */
	if (!*handle) {
		r = efi_create_handle(handle);
		if (r != EFI_SUCCESS)
			goto out;
	}
	/* Find object. */
	list_for_each(lhandle, &efi_obj_list) {
		struct efi_object *efiobj;
		efiobj = list_entry(lhandle, struct efi_object, link);

		if (efiobj->handle != *handle)
			continue;
		/* Check if protocol is already installed on the handle. */
		for (i = 0; i < ARRAY_SIZE(efiobj->protocols); i++) {
			struct efi_handler *handler = &efiobj->protocols[i];

			if (!handler->guid)
				continue;
			if (!guidcmp(handler->guid, protocol)) {
				r = EFI_INVALID_PARAMETER;
				goto out;
			}
		}
		/* Install protocol in first empty slot. */
		for (i = 0; i < ARRAY_SIZE(efiobj->protocols); i++) {
			struct efi_handler *handler = &efiobj->protocols[i];

			if (handler->guid)
				continue;

			handler->guid = protocol;
			handler->protocol_interface = protocol_interface;
			r = EFI_SUCCESS;
			goto out;
		}
		r = EFI_OUT_OF_RESOURCES;
		goto out;
	}
	r = EFI_INVALID_PARAMETER;
out:
	return r;
}

static efi_status_t EFIAPI efi_install_protocol_interface_ext(void **handle,
			efi_guid_t *protocol, int protocol_interface_type,
			void *protocol_interface)
{
	EFI_ENTRY("%p, %pUl, %d, %p", handle, protocol, protocol_interface_type,
		  protocol_interface);

	return EFI_EXIT(efi_install_protocol_interface(handle, protocol,
						       protocol_interface_type,
						       protocol_interface));
}

static efi_status_t EFIAPI efi_reinstall_protocol_interface(void *handle,
			efi_guid_t *protocol, void *old_interface,
			void *new_interface)
{
	EFI_ENTRY("%p, %pUl, %p, %p", handle, protocol, old_interface,
		  new_interface);
	return EFI_EXIT(EFI_ACCESS_DENIED);
}

static efi_status_t EFIAPI efi_uninstall_protocol_interface(void *handle,
			efi_guid_t *protocol, void *protocol_interface)
{
	struct list_head *lhandle;
	int i;
	efi_status_t r = EFI_NOT_FOUND;

	if (!handle || !protocol) {
		r = EFI_INVALID_PARAMETER;
		goto out;
	}

	list_for_each(lhandle, &efi_obj_list) {
		struct efi_object *efiobj;
		efiobj = list_entry(lhandle, struct efi_object, link);

		if (efiobj->handle != handle)
			continue;

		for (i = 0; i < ARRAY_SIZE(efiobj->protocols); i++) {
			struct efi_handler *handler = &efiobj->protocols[i];
			const efi_guid_t *hprotocol = handler->guid;

			if (!hprotocol)
				continue;
			if (!guidcmp(hprotocol, protocol)) {
				if (handler->protocol_interface) {
					r = EFI_ACCESS_DENIED;
				} else {
					handler->guid = 0;
					r = EFI_SUCCESS;
				}
				goto out;
			}
		}
	}

out:
	return r;
}

static efi_status_t EFIAPI efi_uninstall_protocol_interface_ext(void *handle,
			efi_guid_t *protocol, void *protocol_interface)
{
	EFI_ENTRY("%p, %pUl, %p", handle, protocol, protocol_interface);

	return EFI_EXIT(efi_uninstall_protocol_interface(handle, protocol,
							 protocol_interface));
}

static efi_status_t EFIAPI efi_register_protocol_notify(efi_guid_t *protocol,
							struct efi_event *event,
							void **registration)
{
	EFI_ENTRY("%pUl, %p, %p", protocol, event, registration);
	return EFI_EXIT(EFI_OUT_OF_RESOURCES);
}

static int efi_search(enum efi_locate_search_type search_type,
		      efi_guid_t *protocol, void *search_key,
		      struct efi_object *efiobj)
{
	int i;

	switch (search_type) {
	case all_handles:
		return 0;
	case by_register_notify:
		return -1;
	case by_protocol:
		for (i = 0; i < ARRAY_SIZE(efiobj->protocols); i++) {
			const efi_guid_t *guid = efiobj->protocols[i].guid;
			if (guid && !guidcmp(guid, protocol))
				return 0;
		}
		return -1;
	}

	return -1;
}

static efi_status_t efi_locate_handle(
			enum efi_locate_search_type search_type,
			efi_guid_t *protocol, void *search_key,
			unsigned long *buffer_size, efi_handle_t *buffer)
{
	struct list_head *lhandle;
	unsigned long size = 0;

	/* Count how much space we need */
	list_for_each(lhandle, &efi_obj_list) {
		struct efi_object *efiobj;
		efiobj = list_entry(lhandle, struct efi_object, link);
		if (!efi_search(search_type, protocol, search_key, efiobj)) {
			size += sizeof(void*);
		}
	}

	if (*buffer_size < size) {
		*buffer_size = size;
		return EFI_BUFFER_TOO_SMALL;
	}

	*buffer_size = size;
	if (size == 0)
		return EFI_NOT_FOUND;

	/* Then fill the array */
	list_for_each(lhandle, &efi_obj_list) {
		struct efi_object *efiobj;
		efiobj = list_entry(lhandle, struct efi_object, link);
		if (!efi_search(search_type, protocol, search_key, efiobj)) {
			*(buffer++) = efiobj->handle;
		}
	}

	return EFI_SUCCESS;
}

static efi_status_t EFIAPI efi_locate_handle_ext(
			enum efi_locate_search_type search_type,
			efi_guid_t *protocol, void *search_key,
			unsigned long *buffer_size, efi_handle_t *buffer)
{
	EFI_ENTRY("%d, %pUl, %p, %p, %p", search_type, protocol, search_key,
		  buffer_size, buffer);

	return EFI_EXIT(efi_locate_handle(search_type, protocol, search_key,
			buffer_size, buffer));
}

static efi_status_t EFIAPI efi_locate_device_path(efi_guid_t *protocol,
			struct efi_device_path **device_path,
			efi_handle_t *device)
{
	struct efi_object *efiobj;

	EFI_ENTRY("%pUl, %p, %p", protocol, device_path, device);

	efiobj = efi_dp_find_obj(*device_path, device_path);
	if (!efiobj)
		return EFI_EXIT(EFI_NOT_FOUND);

	*device = efiobj->handle;

	return EFI_EXIT(EFI_SUCCESS);
}

/* Collapses configuration table entries, removing index i */
static void efi_remove_configuration_table(int i)
{
	struct efi_configuration_table *this = &efi_conf_table[i];
	struct efi_configuration_table *next = &efi_conf_table[i+1];
	struct efi_configuration_table *end = &efi_conf_table[systab.nr_tables];

	memmove(this, next, (ulong)end - (ulong)next);
	systab.nr_tables--;
}

efi_status_t efi_install_configuration_table(const efi_guid_t *guid, void *table)
{
	int i;

	/* Check for guid override */
	for (i = 0; i < systab.nr_tables; i++) {
		if (!guidcmp(guid, &efi_conf_table[i].guid)) {
			if (table)
				efi_conf_table[i].table = table;
			else
				efi_remove_configuration_table(i);
			return EFI_SUCCESS;
		}
	}

	if (!table)
		return EFI_NOT_FOUND;

	/* No override, check for overflow */
	if (i >= ARRAY_SIZE(efi_conf_table))
		return EFI_OUT_OF_RESOURCES;

	/* Add a new entry */
	memcpy(&efi_conf_table[i].guid, guid, sizeof(*guid));
	efi_conf_table[i].table = table;
	systab.nr_tables = i + 1;

	return EFI_SUCCESS;
}

static efi_status_t EFIAPI efi_install_configuration_table_ext(efi_guid_t *guid,
							       void *table)
{
	EFI_ENTRY("%pUl, %p", guid, table);
	return EFI_EXIT(efi_install_configuration_table(guid, table));
}

/* Initialize a loaded_image_info + loaded_image_info object with correct
 * protocols, boot-device, etc.
 */
void efi_setup_loaded_image(struct efi_loaded_image *info, struct efi_object *obj,
			    struct efi_device_path *device_path,
			    struct efi_device_path *file_path)
{
	obj->handle = info;

	/*
	 * When asking for the device path interface, return
	 * bootefi_device_path
	 */
	obj->protocols[0].guid = &efi_guid_device_path;
	obj->protocols[0].protocol_interface = device_path;

	/*
	 * When asking for the loaded_image interface, just
	 * return handle which points to loaded_image_info
	 */
	obj->protocols[1].guid = &efi_guid_loaded_image;
	obj->protocols[1].protocol_interface = info;

	obj->protocols[2].guid = &efi_guid_console_control;
	obj->protocols[2].protocol_interface = (void *)&efi_console_control;

	obj->protocols[3].guid = &efi_guid_device_path_to_text_protocol;
	obj->protocols[3].protocol_interface =
		(void *)&efi_device_path_to_text;

	info->file_path = file_path;
	info->device_handle = efi_dp_find_obj(device_path, NULL);

	list_add_tail(&obj->link, &efi_obj_list);
}

efi_status_t efi_load_image_from_path(struct efi_device_path *file_path,
				      void **buffer)
{
	struct efi_file_info *info = NULL;
	struct efi_file_handle *f;
	static efi_status_t ret;
	uint64_t bs;

	f = efi_file_from_path(file_path);
	if (!f)
		return EFI_DEVICE_ERROR;

	bs = 0;
	EFI_CALL(ret = f->getinfo(f, (efi_guid_t *)&efi_file_info_guid,
				  &bs, info));
	if (ret == EFI_BUFFER_TOO_SMALL) {
		info = malloc(bs);
		EFI_CALL(ret = f->getinfo(f, (efi_guid_t *)&efi_file_info_guid,
					  &bs, info));
	}
	if (ret != EFI_SUCCESS)
		goto error;

	ret = efi_allocate_pool(EFI_LOADER_DATA, info->file_size, buffer);
	if (ret)
		goto error;

	EFI_CALL(ret = f->read(f, &info->file_size, *buffer));

error:
	free(info);
	EFI_CALL(f->close(f));

	if (ret != EFI_SUCCESS) {
		efi_free_pool(*buffer);
		*buffer = NULL;
	}

	return ret;
}

static efi_status_t EFIAPI efi_load_image(bool boot_policy,
					  efi_handle_t parent_image,
					  struct efi_device_path *file_path,
					  void *source_buffer,
					  unsigned long source_size,
					  efi_handle_t *image_handle)
{
	struct efi_loaded_image *info;
	struct efi_object *obj;

	EFI_ENTRY("%d, %p, %p, %p, %ld, %p", boot_policy, parent_image,
		  file_path, source_buffer, source_size, image_handle);

	info = calloc(1, sizeof(*info));
	obj = calloc(1, sizeof(*obj));

	if (!source_buffer) {
		struct efi_device_path *dp, *fp;
		efi_status_t ret;

		ret = efi_load_image_from_path(file_path, &source_buffer);
		if (ret != EFI_SUCCESS) {
			free(info);
			free(obj);
			return EFI_EXIT(ret);
		}

		/*
		 * split file_path which contains both the device and
		 * file parts:
		 */
		efi_dp_split_file_path(file_path, &dp, &fp);

		efi_setup_loaded_image(info, obj, dp, fp);
	} else {
		/* In this case, file_path is the "device" path, ie.
		 * something like a HARDWARE_DEVICE:MEMORY_MAPPED
		 */
		efi_setup_loaded_image(info, obj, file_path, NULL);
	}

	info->reserved = efi_load_pe(source_buffer, info);
	if (!info->reserved) {
		free(info);
		free(obj);
		return EFI_EXIT(EFI_UNSUPPORTED);
	}

	*image_handle = info;

	return EFI_EXIT(EFI_SUCCESS);
}

static efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
					   unsigned long *exit_data_size,
					   s16 **exit_data)
{
	ulong (*entry)(void *image_handle, struct efi_system_table *st);
	struct efi_loaded_image *info = image_handle;

	EFI_ENTRY("%p, %p, %p", image_handle, exit_data_size, exit_data);
	entry = info->reserved;

	efi_is_direct_boot = false;

	/* call the image! */
	if (setjmp(&info->exit_jmp)) {
		/* We returned from the child image */
		return EFI_EXIT(info->exit_status);
	}

	__efi_nesting_dec();
	__efi_exit_check();
	entry(image_handle, &systab);
	__efi_entry_check();
	__efi_nesting_inc();

	/* Should usually never get here */
	return EFI_EXIT(EFI_SUCCESS);
}

static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
			efi_status_t exit_status, unsigned long exit_data_size,
			int16_t *exit_data)
{
	struct efi_loaded_image *loaded_image_info = (void*)image_handle;

	EFI_ENTRY("%p, %ld, %ld, %p", image_handle, exit_status,
		  exit_data_size, exit_data);

	/* Make sure entry/exit counts for EFI world cross-overs match */
	__efi_exit_check();

	/*
	 * But longjmp out with the U-Boot gd, not the application's, as
	 * the other end is a setjmp call inside EFI context.
	 */
	efi_restore_gd();

	loaded_image_info->exit_status = exit_status;
	longjmp(&loaded_image_info->exit_jmp, 1);

	panic("EFI application exited");
}

static struct efi_object *efi_search_obj(void *handle)
{
	struct list_head *lhandle;

	list_for_each(lhandle, &efi_obj_list) {
		struct efi_object *efiobj;
		efiobj = list_entry(lhandle, struct efi_object, link);
		if (efiobj->handle == handle)
			return efiobj;
	}

	return NULL;
}

static efi_status_t EFIAPI efi_unload_image(void *image_handle)
{
	struct efi_object *efiobj;

	EFI_ENTRY("%p", image_handle);
	efiobj = efi_search_obj(image_handle);