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 */ 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