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_record(u8 type)25 const struct efi_smbios_record *efi_get_smbios_record(u8 type)
26 {
27 struct efi_smbios_record *record;
28 efi_smbios_protocol_t *smbios;
29 efi_status_t status;
30 u16 handle = 0xfffe;
31
32 status = efi_bs_call(locate_protocol, &EFI_SMBIOS_PROTOCOL_GUID, NULL,
33 (void **)&smbios) ?:
34 efi_call_proto(smbios, get_next, &handle, &type, &record, NULL);
35 if (status != EFI_SUCCESS)
36 return NULL;
37 return record;
38 }
39
__efi_get_smbios_string(const struct efi_smbios_record * record,u8 type,int offset)40 const u8 *__efi_get_smbios_string(const struct efi_smbios_record *record,
41 u8 type, int offset)
42 {
43 const u8 *strtable;
44
45 if (!record)
46 return NULL;
47
48 strtable = (u8 *)record + record->length;
49 for (int i = 1; i < ((u8 *)record)[offset]; i++) {
50 int len = strlen(strtable);
51
52 if (!len)
53 return NULL;
54 strtable += len + 1;
55 }
56 return strtable;
57 }
58