1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * EFI device path interface 4 * 5 * Copyright (c) 2017 Leif Lindholm 6 */ 7 8 #include <common.h> 9 #include <efi_loader.h> 10 11 const efi_guid_t efi_guid_device_path_utilities_protocol = 12 EFI_DEVICE_PATH_UTILITIES_PROTOCOL_GUID; 13 14 /* 15 * Get size of a device path. 16 * 17 * This function implements the GetDevicePathSize service of the device path 18 * utilities protocol. The device path length includes the end of path tag 19 * which may be an instance end. 20 * 21 * See the Unified Extensible Firmware Interface (UEFI) specification 22 * for details. 23 * 24 * @device_path device path 25 * @return size in bytes 26 */ 27 static efi_uintn_t EFIAPI get_device_path_size( 28 const struct efi_device_path *device_path) 29 { 30 efi_uintn_t sz = 0; 31 32 EFI_ENTRY("%pD", device_path); 33 /* size includes the END node: */ 34 if (device_path) 35 sz = efi_dp_size(device_path) + sizeof(struct efi_device_path); 36 return EFI_EXIT(sz); 37 } 38 39 /* 40 * Duplicate a device path. 41 * 42 * This function implements the DuplicateDevicePath service of the device path 43 * utilities protocol. 44 * 45 * The UEFI spec does not indicate what happens to the end tag. We follow the 46 * EDK2 logic: In case the device path ends with an end of instance tag, the 47 * copy will also end with an end of instance tag. 48 * 49 * See the Unified Extensible Firmware Interface (UEFI) specification 50 * for details. 51 * 52 * @device_path device path 53 * @return copy of the device path 54 */ 55 static struct efi_device_path * EFIAPI duplicate_device_path( 56 const struct efi_device_path *device_path) 57 { 58 EFI_ENTRY("%pD", device_path); 59 return EFI_EXIT(efi_dp_dup(device_path)); 60 } 61 62 /* 63 * Append device path. 64 * 65 * This function implements the AppendDevicePath service of the device path 66 * utilities protocol. 67 * 68 * See the Unified Extensible Firmware Interface (UEFI) specification 69 * for details. 70 * 71 * @src1 1st device path 72 * @src2 2nd device path 73 * @return concatenated device path 74 */ 75 static struct efi_device_path * EFIAPI append_device_path( 76 const struct efi_device_path *src1, 77 const struct efi_device_path *src2) 78 { 79 EFI_ENTRY("%pD, %pD", src1, src2); 80 return EFI_EXIT(efi_dp_append(src1, src2)); 81 } 82 83 /* 84 * Append device path node. 85 * 86 * This function implements the AppendDeviceNode service of the device path 87 * utilities protocol. 88 * 89 * See the Unified Extensible Firmware Interface (UEFI) specification 90 * for details. 91 * 92 * @device_path device path 93 * @device_node device node 94 * @return concatenated device path 95 */ 96 static struct efi_device_path * EFIAPI append_device_node( 97 const struct efi_device_path *device_path, 98 const struct efi_device_path *device_node) 99 { 100 EFI_ENTRY("%pD, %p", device_path, device_node); 101 return EFI_EXIT(efi_dp_append_node(device_path, device_node)); 102 } 103 104 /* 105 * Append device path instance. 106 * 107 * This function implements the AppendDevicePathInstance service of the device 108 * path utilities protocol. 109 * 110 * See the Unified Extensible Firmware Interface (UEFI) specification 111 * for details. 112 * 113 * @device_path 1st device path 114 * @device_path_instance 2nd device path 115 * @return concatenated device path 116 */ 117 static struct efi_device_path * EFIAPI append_device_path_instance( 118 const struct efi_device_path *device_path, 119 const struct efi_device_path *device_path_instance) 120 { 121 EFI_ENTRY("%pD, %pD", device_path, device_path_instance); 122 return EFI_EXIT(efi_dp_append_instance(device_path, 123 device_path_instance)); 124 } 125 126 /* 127 * Get next device path instance. 128 * 129 * This function implements the GetNextDevicePathInstance service of the device 130 * path utilities protocol. 131 * 132 * See the Unified Extensible Firmware Interface (UEFI) specification 133 * for details. 134 * 135 * @device_path_instance next device path instance 136 * @device_path_instance_size size of the device path instance 137 * @return concatenated device path 138 */ 139 static struct efi_device_path * EFIAPI get_next_device_path_instance( 140 struct efi_device_path **device_path_instance, 141 efi_uintn_t *device_path_instance_size) 142 { 143 EFI_ENTRY("%pD, %p", device_path_instance, device_path_instance_size); 144 return EFI_EXIT(efi_dp_get_next_instance(device_path_instance, 145 device_path_instance_size)); 146 } 147 148 /* 149 * Check if a device path contains more than one instance. 150 * 151 * This function implements the AppendDeviceNode service of the device path 152 * utilities protocol. 153 * 154 * See the Unified Extensible Firmware Interface (UEFI) specification 155 * for details. 156 * 157 * @device_path device path 158 * @device_node device node 159 * @return concatenated device path 160 */ 161 static bool EFIAPI is_device_path_multi_instance( 162 const struct efi_device_path *device_path) 163 { 164 EFI_ENTRY("%pD", device_path); 165 return EFI_EXIT(efi_dp_is_multi_instance(device_path)); 166 } 167 168 /* 169 * Create device node. 170 * 171 * This function implements the CreateDeviceNode service of the device path 172 * utilities protocol. 173 * 174 * See the Unified Extensible Firmware Interface (UEFI) specification 175 * for details. 176 * 177 * @node_type node type 178 * @node_sub_type node sub type 179 * @node_length node length 180 * @return device path node 181 */ 182 static struct efi_device_path * EFIAPI create_device_node( 183 uint8_t node_type, uint8_t node_sub_type, uint16_t node_length) 184 { 185 EFI_ENTRY("%u, %u, %u", node_type, node_sub_type, node_length); 186 return EFI_EXIT(efi_dp_create_device_node(node_type, node_sub_type, 187 node_length)); 188 } 189 190 const struct efi_device_path_utilities_protocol efi_device_path_utilities = { 191 .get_device_path_size = get_device_path_size, 192 .duplicate_device_path = duplicate_device_path, 193 .append_device_path = append_device_path, 194 .append_device_node = append_device_node, 195 .append_device_path_instance = append_device_path_instance, 196 .get_next_device_path_instance = get_next_device_path_instance, 197 .is_device_path_multi_instance = is_device_path_multi_instance, 198 .create_device_node = create_device_node, 199 }; 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