include/efi_loader.h

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

#include <common.h>
#include <part_efi.h>
#include <efi_api.h>

/* No need for efi loader support in SPL */
#if defined(CONFIG_EFI_LOADER) && !defined(CONFIG_SPL_BUILD)

#include <linux/list.h>

/* #define DEBUG_EFI */

#ifdef DEBUG_EFI
#define EFI_ENTRY(format, ...) do { \
	efi_restore_gd(); \
	printf("EFI: Entry %s(" format ")\n", __func__, ##__VA_ARGS__); \
	} while(0)
#else
#define EFI_ENTRY(format, ...) do { \
	efi_restore_gd(); \
	} while(0)
#endif

#define EFI_EXIT(ret) efi_exit_func(ret);

extern struct efi_system_table systab;

extern const struct efi_simple_text_output_protocol efi_con_out;
extern const struct efi_simple_input_interface efi_con_in;
extern const struct efi_console_control_protocol efi_console_control;

extern const efi_guid_t efi_guid_console_control;
extern const efi_guid_t efi_guid_device_path;
extern const efi_guid_t efi_guid_loaded_image;

/*
 * While UEFI objects can have callbacks, you can also call functions on
 * protocols (classes) themselves. This struct maps a protocol GUID to its
 * interface (usually a struct with callback functions).
 */
struct efi_class_map {
	const efi_guid_t *guid;
	const void *interface;
};

/*
 * When the UEFI payload wants to open a protocol on an object to get its
 * interface (usually a struct with callback functions), this struct maps the
 * protocol GUID to the respective protocol handler open function for that
 * object protocol combination.
 */
struct efi_handler {
	const efi_guid_t *guid;
	efi_status_t (EFIAPI *open)(void *handle,
			efi_guid_t *protocol, void **protocol_interface,
			void *agent_handle, void *controller_handle,
			uint32_t attributes);
};

/*
 * UEFI has a poor man's OO model where one "object" can be polymorphic and have
 * multiple different protocols (classes) attached to it.
 *
 * This struct is the parent struct for all of our actual implementation objects
 * that can include it to make themselves an EFI object
 */
struct efi_object {
	/* Every UEFI object is part of a global object list */
	struct list_head link;
	/* We support up to 4 "protocols" an object can be accessed through */
	struct efi_handler protocols[4];
	/* The object spawner can either use this for data or as identifier */
	void *handle;
};

/* This list contains all UEFI objects we know of */
extern struct list_head efi_obj_list;

/*
 * Stub implementation for a protocol opener that just returns the handle as
 * interface
 */
efi_status_t efi_return_handle(void *handle,
		efi_guid_t *protocol, void **protocol_interface,
		void *agent_handle, void *controller_handle,
		uint32_t attributes);
/* Called from places to check whether a timer expired */
void efi_timer_check(void);
/* PE loader implementation */
void *efi_load_pe(void *efi, struct efi_loaded_image *loaded_image_info);
/* Called once to store the pristine gd pointer */
void efi_save_gd(void);
/* Called from EFI_ENTRY on callback entry to put gd into the gd register */
void efi_restore_gd(void);
/* Called from EFI_EXIT on callback exit to restore the gd register */
efi_status_t efi_exit_func(efi_status_t ret);

#else /* defined(EFI_LOADER) && !defined(CONFIG_SPL_BUILD) */

/* No loader configured, stub out EFI_ENTRY */
static inline void efi_restore_gd(void) { }

#endif