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1// SPDX-License-Identifier: GPL-2.0-only2// Copyright 2022 Google LLC3// Author: Ard Biesheuvel <ardb@google.com>4 5#include <linux/efi.h>6 7#include "efistub.h"8 9typedef union efi_smbios_protocol efi_smbios_protocol_t;10 11union 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 36const 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 51const 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