| 1 | // SPDX-License-Identifier: GPL-2.0-only |
|---|---|
| 2 | // Copyright 2022 Google LLC |
| 3 | // Author: Ard Biesheuvel <ardb@google.com> |
| 4 | |
| 5 | #include <linux/efi.h> |
| 6 | |
| 7 | #include "efistub.h" |
| 8 | |
| 9 | typedef union efi_smbios_protocol efi_smbios_protocol_t; |
| 10 | |
| 11 | union efi_smbios_protocol { |
| 12 | struct { |
| 13 | efi_status_t (__efiapi *add)(efi_smbios_protocol_t *, efi_handle_t, |
| 14 | u16 *, struct efi_smbios_record *); |
| 15 | efi_status_t (__efiapi *update_string)(efi_smbios_protocol_t *, u16 *, |
| 16 | unsigned long *, u8 *); |
| 17 | efi_status_t (__efiapi *remove)(efi_smbios_protocol_t *, u16); |
| 18 | efi_status_t (__efiapi *get_next)(efi_smbios_protocol_t *, u16 *, u8 *, |
| 19 | struct efi_smbios_record **, |
| 20 | efi_handle_t *); |
| 21 | |
| 22 | u8 major_version; |
| 23 | u8 minor_version; |
| 24 | }; |
| 25 | struct { |
| 26 | u32 add; |
| 27 | u32 update_string; |
| 28 | u32 remove; |
| 29 | u32 get_next; |
| 30 | |
| 31 | u8 major_version; |
| 32 | u8 minor_version; |
| 33 | } mixed_mode; |
| 34 | }; |
| 35 | |
| 36 | const struct efi_smbios_record *efi_get_smbios_record(u8 type) |
| 37 | { |
| 38 | struct efi_smbios_record *record; |
| 39 | efi_smbios_protocol_t *smbios; |
| 40 | efi_status_t status; |
| 41 | u16 handle = 0xfffe; |
| 42 | |
| 43 | status = efi_bs_call(locate_protocol, &EFI_SMBIOS_PROTOCOL_GUID, NULL, |
| 44 | (void **)&smbios) ?: |
| 45 | efi_call_proto(smbios, get_next, &handle, &type, &record, NULL); |
| 46 | if (status != EFI_SUCCESS) |
| 47 | return NULL; |
| 48 | return record; |
| 49 | } |
| 50 | |
| 51 | const u8 *__efi_get_smbios_string(const struct efi_smbios_record *record, |
| 52 | const u8 *offset) |
| 53 | { |
| 54 | const u8 *strtable; |
| 55 | |
| 56 | if (!record) |
| 57 | return NULL; |
| 58 | |
| 59 | strtable = (u8 *)record + record->length; |
| 60 | for (int i = 1; i < *offset; i++) { |
| 61 | int len = strlen(strtable); |
| 62 | |
| 63 | if (!len) |
| 64 | return NULL; |
| 65 | strtable += len + 1; |
| 66 | } |
| 67 | return strtable; |
| 68 | } |
| 69 |