1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * EFI application tables support
4 *
5 * Copyright (c) 2016 Alexander Graf
6 */
7
8 #include <common.h>
9 #include <efi_loader.h>
10 #include <mapmem.h>
11 #include <smbios.h>
12
13 static const efi_guid_t smbios_guid = SMBIOS_TABLE_GUID;
14
15 /*
16 * Install the SMBIOS table as a configuration table.
17 *
18 * @return status code
19 */
efi_smbios_register(void)20 efi_status_t efi_smbios_register(void)
21 {
22 /* Map within the low 32 bits, to allow for 32bit SMBIOS tables */
23 u64 dmi_addr = U32_MAX;
24 efi_status_t ret;
25 void *dmi;
26
27 /* Reserve 4kiB page for SMBIOS */
28 ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
29 EFI_RUNTIME_SERVICES_DATA, 1, &dmi_addr);
30
31 if (ret != EFI_SUCCESS) {
32 /* Could not find space in lowmem, use highmem instead */
33 ret = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES,
34 EFI_RUNTIME_SERVICES_DATA, 1,
35 &dmi_addr);
36
37 if (ret != EFI_SUCCESS)
38 return ret;
39 }
40
41 /*
42 * Generate SMBIOS tables - we know that efi_allocate_pages() returns
43 * a 4k-aligned address, so it is safe to assume that
44 * write_smbios_table() will write the table at that address.
45 *
46 * Note that on sandbox, efi_allocate_pages() unfortunately returns a
47 * pointer even though it uses a uint64_t type. Convert it.
48 */
49 assert(!(dmi_addr & 0xf));
50 dmi = (void *)(uintptr_t)dmi_addr;
51 write_smbios_table(map_to_sysmem(dmi));
52
53 /* And expose them to our EFI payload */
54 return efi_install_configuration_table(&smbios_guid, dmi);
55 }
56