u-boot/lib/efi_loader/efi_acpi.c
Bin Meng 86df34d42b efi_loader: Install ACPI configuration tables
ACPI tables can be passed via EFI configuration table to an EFI
application. This is only supported on x86 so far.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2018-07-02 09:23:28 +08:00

43 lines
1.0 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* EFI application ACPI tables support
*
* Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
*/
#include <common.h>
#include <efi_loader.h>
#include <asm/acpi_table.h>
static const efi_guid_t acpi_guid = EFI_ACPI_TABLE_GUID;
/*
* Install the ACPI table as a configuration table.
*
* @return status code
*/
efi_status_t efi_acpi_register(void)
{
/* Map within the low 32 bits, to allow for 32bit ACPI tables */
u64 acpi = U32_MAX;
efi_status_t ret;
/* Reserve 64kiB page for ACPI */
ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
EFI_RUNTIME_SERVICES_DATA, 16, &acpi);
if (ret != EFI_SUCCESS)
return ret;
/*
* Generate ACPI tables - we know that efi_allocate_pages() returns
* a 4k-aligned address, so it is safe to assume that
* write_acpi_tables() will write the table at that address.
*/
assert(!(acpi & 0xf));
write_acpi_tables(acpi);
/* And expose them to our EFI payload */
return efi_install_configuration_table(&acpi_guid,
(void *)(uintptr_t)acpi);
}