1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * EFI application ACPI tables support 4 * 5 * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com> 6 */ 7 8 #include <common.h> 9 #include <efi_loader.h> 10 #include <asm/acpi_table.h> 11 12 static const efi_guid_t acpi_guid = EFI_ACPI_TABLE_GUID; 13 14 /* 15 * Install the ACPI table as a configuration table. 16 * 17 * @return status code 18 */ 19 efi_status_t efi_acpi_register(void) 20 { 21 /* Map within the low 32 bits, to allow for 32bit ACPI tables */ 22 u64 acpi = U32_MAX; 23 efi_status_t ret; 24 25 /* Reserve 64kiB page for ACPI */ 26 ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS, 27 EFI_RUNTIME_SERVICES_DATA, 16, &acpi); 28 if (ret != EFI_SUCCESS) 29 return ret; 30 31 /* 32 * Generate ACPI tables - we know that efi_allocate_pages() returns 33 * a 4k-aligned address, so it is safe to assume that 34 * write_acpi_tables() will write the table at that address. 35 */ 36 assert(!(acpi & 0xf)); 37 write_acpi_tables(acpi); 38 39 /* And expose them to our EFI payload */ 40 return efi_install_configuration_table(&acpi_guid, 41 (void *)(uintptr_t)acpi); 42 } 43