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 <log.h>
11 #include <mapmem.h>
12 #include <smbios.h>
13
14 static const efi_guid_t smbios_guid = SMBIOS_TABLE_GUID;
15
16 /*
17 * Install the SMBIOS table as a configuration table.
18 *
19 * @return status code
20 */
efi_smbios_register(void)21 efi_status_t efi_smbios_register(void)
22 {
23 /* Map within the low 32 bits, to allow for 32bit SMBIOS tables */
24 u64 dmi_addr = U32_MAX;
25 efi_status_t ret;
26 void *dmi;
27
28 /* Reserve 4kiB page for SMBIOS */
29 ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
30 EFI_RUNTIME_SERVICES_DATA, 1, &dmi_addr);
31
32 if (ret != EFI_SUCCESS) {
33 /* Could not find space in lowmem, use highmem instead */
34 ret = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES,
35 EFI_RUNTIME_SERVICES_DATA, 1,
36 &dmi_addr);
37
38 if (ret != EFI_SUCCESS)
39 return ret;
40 }
41
42 /*
43 * Generate SMBIOS tables - we know that efi_allocate_pages() returns
44 * a 4k-aligned address, so it is safe to assume that
45 * write_smbios_table() will write the table at that address.
46 *
47 * Note that on sandbox, efi_allocate_pages() unfortunately returns a
48 * pointer even though it uses a uint64_t type. Convert it.
49 */
50 assert(!(dmi_addr & 0xf));
51 dmi = (void *)(uintptr_t)dmi_addr;
52 write_smbios_table(map_to_sysmem(dmi));
53
54 /* And expose them to our EFI payload */
55 return efi_install_configuration_table(&smbios_guid, dmi);
56 }
57