linux-zen-desktop/drivers/firmware/efi/libstub/smbios.c

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2023-08-30 17:31:07 +02:00
// SPDX-License-Identifier: GPL-2.0-only
// Copyright 2022 Google LLC
// Author: Ard Biesheuvel <ardb@google.com>
#include <linux/efi.h>
#include "efistub.h"
typedef struct efi_smbios_protocol efi_smbios_protocol_t;
struct efi_smbios_protocol {
efi_status_t (__efiapi *add)(efi_smbios_protocol_t *, efi_handle_t,
u16 *, struct efi_smbios_record *);
efi_status_t (__efiapi *update_string)(efi_smbios_protocol_t *, u16 *,
unsigned long *, u8 *);
efi_status_t (__efiapi *remove)(efi_smbios_protocol_t *, u16);
efi_status_t (__efiapi *get_next)(efi_smbios_protocol_t *, u16 *, u8 *,
struct efi_smbios_record **,
efi_handle_t *);
u8 major_version;
u8 minor_version;
};
const struct efi_smbios_record *efi_get_smbios_record(u8 type)
{
struct efi_smbios_record *record;
efi_smbios_protocol_t *smbios;
efi_status_t status;
u16 handle = 0xfffe;
status = efi_bs_call(locate_protocol, &EFI_SMBIOS_PROTOCOL_GUID, NULL,
(void **)&smbios) ?:
efi_call_proto(smbios, get_next, &handle, &type, &record, NULL);
if (status != EFI_SUCCESS)
return NULL;
return record;
}
const u8 *__efi_get_smbios_string(const struct efi_smbios_record *record,
u8 type, int offset)
{
const u8 *strtable;
if (!record)
return NULL;
strtable = (u8 *)record + record->length;
for (int i = 1; i < ((u8 *)record)[offset]; i++) {
int len = strlen(strtable);
if (!len)
return NULL;
strtable += len + 1;
}
return strtable;
}