1 /* 2 * EFI application loader 3 * 4 * Copyright (c) 2016 Alexander Graf 5 * 6 * SPDX-License-Identifier: GPL-2.0+ 7 */ 8 9 #include <common.h> 10 #include <part_efi.h> 11 #include <efi_api.h> 12 13 /* No need for efi loader support in SPL */ 14 #if defined(CONFIG_EFI_LOADER) && !defined(CONFIG_SPL_BUILD) 15 16 #include <linux/list.h> 17 18 /* #define DEBUG_EFI */ 19 20 #ifdef DEBUG_EFI 21 #define EFI_ENTRY(format, ...) do { \ 22 efi_restore_gd(); \ 23 printf("EFI: Entry %s(" format ")\n", __func__, ##__VA_ARGS__); \ 24 } while(0) 25 #else 26 #define EFI_ENTRY(format, ...) do { \ 27 efi_restore_gd(); \ 28 } while(0) 29 #endif 30 31 #define EFI_EXIT(ret) efi_exit_func(ret); 32 33 extern struct efi_system_table systab; 34 35 extern const efi_guid_t efi_guid_device_path; 36 extern const efi_guid_t efi_guid_loaded_image; 37 38 /* 39 * While UEFI objects can have callbacks, you can also call functions on 40 * protocols (classes) themselves. This struct maps a protocol GUID to its 41 * interface (usually a struct with callback functions). 42 */ 43 struct efi_class_map { 44 const efi_guid_t *guid; 45 const void *interface; 46 }; 47 48 /* 49 * When the UEFI payload wants to open a protocol on an object to get its 50 * interface (usually a struct with callback functions), this struct maps the 51 * protocol GUID to the respective protocol handler open function for that 52 * object protocol combination. 53 */ 54 struct efi_handler { 55 const efi_guid_t *guid; 56 efi_status_t (EFIAPI *open)(void *handle, 57 efi_guid_t *protocol, void **protocol_interface, 58 void *agent_handle, void *controller_handle, 59 uint32_t attributes); 60 }; 61 62 /* 63 * UEFI has a poor man's OO model where one "object" can be polymorphic and have 64 * multiple different protocols (classes) attached to it. 65 * 66 * This struct is the parent struct for all of our actual implementation objects 67 * that can include it to make themselves an EFI object 68 */ 69 struct efi_object { 70 /* Every UEFI object is part of a global object list */ 71 struct list_head link; 72 /* We support up to 4 "protocols" an object can be accessed through */ 73 struct efi_handler protocols[4]; 74 /* The object spawner can either use this for data or as identifier */ 75 void *handle; 76 }; 77 78 /* This list contains all UEFI objects we know of */ 79 extern struct list_head efi_obj_list; 80 81 /* 82 * Stub implementation for a protocol opener that just returns the handle as 83 * interface 84 */ 85 efi_status_t efi_return_handle(void *handle, 86 efi_guid_t *protocol, void **protocol_interface, 87 void *agent_handle, void *controller_handle, 88 uint32_t attributes); 89 /* Called from places to check whether a timer expired */ 90 void efi_timer_check(void); 91 /* PE loader implementation */ 92 void *efi_load_pe(void *efi, struct efi_loaded_image *loaded_image_info); 93 /* Called once to store the pristine gd pointer */ 94 void efi_save_gd(void); 95 /* Called from EFI_ENTRY on callback entry to put gd into the gd register */ 96 void efi_restore_gd(void); 97 /* Called from EFI_EXIT on callback exit to restore the gd register */ 98 efi_status_t efi_exit_func(efi_status_t ret); 99 100 #else /* defined(EFI_LOADER) && !defined(CONFIG_SPL_BUILD) */ 101 102 /* No loader configured, stub out EFI_ENTRY */ 103 static inline void efi_restore_gd(void) { } 104 105 #endif 106