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 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