Ilias Apalodimas | aa0f755 | 2021-03-17 21:54:59 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * Copyright (c) 2020, Linaro Limited |
| 4 | */ |
| 5 | |
| 6 | #define LOG_CATEGORY LOGC_EFI |
| 7 | #include <common.h> |
| 8 | #include <env.h> |
| 9 | #include <malloc.h> |
| 10 | #include <dm.h> |
| 11 | #include <fs.h> |
| 12 | #include <efi_load_initrd.h> |
| 13 | #include <efi_loader.h> |
| 14 | #include <efi_variable.h> |
| 15 | |
Heinrich Schuchardt | 6c405cb | 2021-10-15 02:33:33 +0200 | [diff] [blame] | 16 | #if defined(CONFIG_CMD_EFIDEBUG) || defined(CONFIG_EFI_LOAD_FILE2_INITRD) |
| 17 | /* GUID used by Linux to identify the LoadFile2 protocol with the initrd */ |
| 18 | const efi_guid_t efi_lf2_initrd_guid = EFI_INITRD_MEDIA_GUID; |
| 19 | #endif |
| 20 | |
Ilias Apalodimas | aa0f755 | 2021-03-17 21:54:59 +0200 | [diff] [blame] | 21 | /** |
| 22 | * efi_create_current_boot_var() - Return Boot#### name were #### is replaced by |
| 23 | * the value of BootCurrent |
| 24 | * |
| 25 | * @var_name: variable name |
| 26 | * @var_name_size: size of var_name |
| 27 | * |
| 28 | * Return: Status code |
| 29 | */ |
| 30 | static efi_status_t efi_create_current_boot_var(u16 var_name[], |
| 31 | size_t var_name_size) |
| 32 | { |
| 33 | efi_uintn_t boot_current_size; |
| 34 | efi_status_t ret; |
| 35 | u16 boot_current; |
| 36 | u16 *pos; |
| 37 | |
| 38 | boot_current_size = sizeof(boot_current); |
| 39 | ret = efi_get_variable_int(L"BootCurrent", |
| 40 | &efi_global_variable_guid, NULL, |
| 41 | &boot_current_size, &boot_current, NULL); |
| 42 | if (ret != EFI_SUCCESS) |
| 43 | goto out; |
| 44 | |
| 45 | pos = efi_create_indexed_name(var_name, var_name_size, "Boot", |
| 46 | boot_current); |
| 47 | if (!pos) { |
| 48 | ret = EFI_OUT_OF_RESOURCES; |
| 49 | goto out; |
| 50 | } |
| 51 | |
| 52 | out: |
| 53 | return ret; |
| 54 | } |
| 55 | |
| 56 | /** |
| 57 | * efi_get_dp_from_boot() - Retrieve and return a device path from an EFI |
| 58 | * Boot### variable. |
| 59 | * A boot option may contain an array of device paths. |
| 60 | * We use a VenMedia() with a specific GUID to identify |
| 61 | * the usage of the array members. This function is |
| 62 | * used to extract a specific device path |
| 63 | * |
| 64 | * @guid: vendor GUID of the VenMedia() device path node identifying the |
| 65 | * device path |
| 66 | * |
| 67 | * Return: device path or NULL. Caller must free the returned value |
| 68 | */ |
| 69 | struct efi_device_path *efi_get_dp_from_boot(const efi_guid_t guid) |
| 70 | { |
Ilias Apalodimas | aa0f755 | 2021-03-17 21:54:59 +0200 | [diff] [blame] | 71 | struct efi_load_option lo; |
Heinrich Schuchardt | 35dd322 | 2021-10-15 02:59:15 +0200 | [diff] [blame] | 72 | void *var_value; |
Ilias Apalodimas | aa0f755 | 2021-03-17 21:54:59 +0200 | [diff] [blame] | 73 | efi_uintn_t size; |
| 74 | efi_status_t ret; |
| 75 | u16 var_name[16]; |
| 76 | |
| 77 | ret = efi_create_current_boot_var(var_name, sizeof(var_name)); |
| 78 | if (ret != EFI_SUCCESS) |
| 79 | return NULL; |
| 80 | |
| 81 | var_value = efi_get_var(var_name, &efi_global_variable_guid, &size); |
| 82 | if (!var_value) |
| 83 | return NULL; |
| 84 | |
| 85 | ret = efi_deserialize_load_option(&lo, var_value, &size); |
| 86 | if (ret != EFI_SUCCESS) |
Heinrich Schuchardt | 35dd322 | 2021-10-15 02:59:15 +0200 | [diff] [blame] | 87 | goto err; |
Ilias Apalodimas | aa0f755 | 2021-03-17 21:54:59 +0200 | [diff] [blame] | 88 | |
Heinrich Schuchardt | 35dd322 | 2021-10-15 02:59:15 +0200 | [diff] [blame] | 89 | return efi_dp_from_lo(&lo, &guid); |
Ilias Apalodimas | aa0f755 | 2021-03-17 21:54:59 +0200 | [diff] [blame] | 90 | |
Heinrich Schuchardt | 35dd322 | 2021-10-15 02:59:15 +0200 | [diff] [blame] | 91 | err: |
Ilias Apalodimas | aa0f755 | 2021-03-17 21:54:59 +0200 | [diff] [blame] | 92 | free(var_value); |
Heinrich Schuchardt | 35dd322 | 2021-10-15 02:59:15 +0200 | [diff] [blame] | 93 | return NULL; |
Ilias Apalodimas | aa0f755 | 2021-03-17 21:54:59 +0200 | [diff] [blame] | 94 | } |