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 struct efi_smbios_protocol efi_smbios_protocol_t;
10
11 struct efi_smbios_protocol {
12 efi_status_t (__efiapi *add)(efi_smbios_protocol_t *, efi_handle_t,
13 u16 *, struct efi_smbios_record *);
14 efi_status_t (__efiapi *update_string)(efi_smbios_protocol_t *, u16 *,
15 unsigned long *, u8 *);
16 efi_status_t (__efiapi *remove)(efi_smbios_protocol_t *, u16);
17 efi_status_t (__efiapi *get_next)(efi_smbios_protocol_t *, u16 *, u8 *,
18 struct efi_smbios_record **,
19 efi_handle_t *);
20
21 u8 major_version;
22 u8 minor_version;
23 };
24
__efi_get_smbios_string(u8 type,int offset,int recsize)25 const u8 *__efi_get_smbios_string(u8 type, int offset, int recsize)
26 {
27 struct efi_smbios_record *record;
28 efi_smbios_protocol_t *smbios;
29 efi_status_t status;
30 u16 handle = 0xfffe;
31 const u8 *strtable;
32
33 status = efi_bs_call(locate_protocol, &EFI_SMBIOS_PROTOCOL_GUID, NULL,
34 (void **)&smbios) ?:
35 efi_call_proto(smbios, get_next, &handle, &type, &record, NULL);
36 if (status != EFI_SUCCESS)
37 return NULL;
38
39 strtable = (u8 *)record + recsize;
40 for (int i = 1; i < ((u8 *)record)[offset]; i++) {
41 int len = strlen(strtable);
42
43 if (!len)
44 return NULL;
45 strtable += len + 1;
46 }
47 return strtable;
48 }
49