u-boot-brain/lib/efi_loader/efi_setup.c
Ilias Apalodimas ec80b4735a efi_loader: Implement FileLoad2 for initramfs loading
Following kernel's proposal for an arch-agnostic initrd loading
mechanism [1] let's implement the U-boot counterpart.
This new approach has a number of advantages compared to what we did up
to now. The file is loaded into memory only when requested limiting the
area of TOCTOU attacks. Users will be allowed to place the initramfs
file on any u-boot accessible partition instead of just the ESP one.
Finally this is an attempt of a generic interface across architectures
in the linux kernel so it makes sense to support that.

The file location is intentionally only supported as a config option
argument(CONFIG_EFI_INITRD_FILESPEC), in an effort to enhance security.
Although U-boot is not responsible for verifying the integrity of the
initramfs, we can enhance the offered security by only accepting a
built-in option, which will be naturally verified by UEFI Secure Boot.
This can easily change in the future if needed and configure that via ENV
or UEFI variable.

[1] https://lore.kernel.org/linux-efi/20200207202637.GA3464906@rani.riverdale.lan/T/#m4a25eb33112fab7a22faa0fd65d4d663209af32f

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-02-28 19:37:14 +01:00

191 lines
4.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* EFI setup code
*
* Copyright (c) 2016-2018 Alexander Graf et al.
*/
#include <common.h>
#include <bootm.h>
#include <efi_loader.h>
#define OBJ_LIST_NOT_INITIALIZED 1
static efi_status_t efi_obj_list_initialized = OBJ_LIST_NOT_INITIALIZED;
/*
* Allow unaligned memory access.
*
* This routine is overridden by architectures providing this feature.
*/
void __weak allow_unaligned(void)
{
}
/**
* efi_init_platform_lang() - define supported languages
*
* Set the PlatformLangCodes and PlatformLang variables.
*
* Return: status code
*/
static efi_status_t efi_init_platform_lang(void)
{
efi_status_t ret;
efi_uintn_t data_size = 0;
char *lang = CONFIG_EFI_PLATFORM_LANG_CODES;
char *pos;
/*
* Variable PlatformLangCodes defines the language codes that the
* machine can support.
*/
ret = EFI_CALL(efi_set_variable(L"PlatformLangCodes",
&efi_global_variable_guid,
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
sizeof(CONFIG_EFI_PLATFORM_LANG_CODES),
CONFIG_EFI_PLATFORM_LANG_CODES));
if (ret != EFI_SUCCESS)
goto out;
/*
* Variable PlatformLang defines the language that the machine has been
* configured for.
*/
ret = EFI_CALL(efi_get_variable(L"PlatformLang",
&efi_global_variable_guid,
NULL, &data_size, &pos));
if (ret == EFI_BUFFER_TOO_SMALL) {
/* The variable is already set. Do not change it. */
ret = EFI_SUCCESS;
goto out;
}
/*
* The list of supported languages is semicolon separated. Use the first
* language to initialize PlatformLang.
*/
pos = strchr(lang, ';');
if (pos)
*pos = 0;
ret = EFI_CALL(efi_set_variable(L"PlatformLang",
&efi_global_variable_guid,
EFI_VARIABLE_NON_VOLATILE |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
1 + strlen(lang), lang));
out:
if (ret != EFI_SUCCESS)
printf("EFI: cannot initialize platform language settings\n");
return ret;
}
/**
* efi_init_obj_list() - Initialize and populate EFI object list
*
* Return: status code
*/
efi_status_t efi_init_obj_list(void)
{
u64 os_indications_supported = 0; /* None */
efi_status_t ret = EFI_SUCCESS;
/* Initialize once only */
if (efi_obj_list_initialized != OBJ_LIST_NOT_INITIALIZED)
return efi_obj_list_initialized;
/* Allow unaligned memory access */
allow_unaligned();
/* On ARM switch from EL3 or secure mode to EL2 or non-secure mode */
switch_to_non_secure_mode();
/* Initialize variable services */
ret = efi_init_variables();
if (ret != EFI_SUCCESS)
goto out;
/* Define supported languages */
ret = efi_init_platform_lang();
if (ret != EFI_SUCCESS)
goto out;
/* Indicate supported features */
ret = EFI_CALL(efi_set_variable(L"OsIndicationsSupported",
&efi_global_variable_guid,
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
sizeof(os_indications_supported),
&os_indications_supported));
if (ret != EFI_SUCCESS)
goto out;
/* Initialize system table */
ret = efi_initialize_system_table();
if (ret != EFI_SUCCESS)
goto out;
/* Indicate supported runtime services */
ret = efi_init_runtime_supported();
if (ret != EFI_SUCCESS)
goto out;
/* Initialize root node */
ret = efi_root_node_register();
if (ret != EFI_SUCCESS)
goto out;
/* Initialize EFI driver uclass */
ret = efi_driver_init();
if (ret != EFI_SUCCESS)
goto out;
ret = efi_console_register();
if (ret != EFI_SUCCESS)
goto out;
#ifdef CONFIG_PARTITIONS
ret = efi_disk_register();
if (ret != EFI_SUCCESS)
goto out;
#endif
#if defined(CONFIG_LCD) || defined(CONFIG_DM_VIDEO)
ret = efi_gop_register();
if (ret != EFI_SUCCESS)
goto out;
#endif
#ifdef CONFIG_EFI_LOAD_FILE2_INITRD
ret = efi_initrd_register();
if (ret != EFI_SUCCESS)
goto out;
#endif
#ifdef CONFIG_NET
ret = efi_net_register();
if (ret != EFI_SUCCESS)
goto out;
#endif
#ifdef CONFIG_GENERATE_ACPI_TABLE
ret = efi_acpi_register();
if (ret != EFI_SUCCESS)
goto out;
#endif
#ifdef CONFIG_GENERATE_SMBIOS_TABLE
ret = efi_smbios_register();
if (ret != EFI_SUCCESS)
goto out;
#endif
ret = efi_watchdog_register();
if (ret != EFI_SUCCESS)
goto out;
/* Initialize EFI runtime services */
ret = efi_reset_system_init();
if (ret != EFI_SUCCESS)
goto out;
out:
efi_obj_list_initialized = ret;
return ret;
}