1 // SPDX-License-Identifier: GPL-2.0+
3 * EFI application ACPI tables support
5 * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
9 #include <efi_loader.h>
10 #include <asm/acpi_table.h>
12 static const efi_guid_t acpi_guid = EFI_ACPI_TABLE_GUID;
15 * Install the ACPI table as a configuration table.
19 efi_status_t efi_acpi_register(void)
21 /* Map within the low 32 bits, to allow for 32bit ACPI tables */
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)
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.
36 assert(!(acpi & 0xf));
37 write_acpi_tables(acpi);
39 /* And expose them to our EFI payload */
40 return efi_install_configuration_table(&acpi_guid,
41 (void *)(uintptr_t)acpi);