Re: [PATCH 10/10] Add command to set an environment variable to an EFI variable

Hi Heinrich,

On Sun, 24 Nov 2024 at 08:11, Heinrich Schuchardt xypron.glpk@gmx.de wrote:

On 11/23/24 20:55, Matthew Garrett wrote:

...

From: Matthew Garrett mgarrett@aurora.tech

We may want to make things conditional on EFI variable state

Signed-off-by: Matthew Garrett mgarrett@aurora.tech

cmd/Kconfig | 4 ++ cmd/Makefile | 1 + cmd/efigetenv.c | 133 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 138 insertions(+) create mode 100644 cmd/efigetenv.c

diff --git a/cmd/Kconfig b/cmd/Kconfig index 33bf3d1ad39..118fb721081 100644 --- a/cmd/Kconfig +++ b/cmd/Kconfig @@ -752,6 +752,10 @@ config CMD_NVEDIT_SELECT help Select the compiled-in persistent storage of environment variables.

+config CMD_EFI_GET_ENV

• bool "efi get env"
  

• help
  

•   Set an environment variable to the contents of an EFI variable
  

  endmenu

  menu "Memory commands"

diff --git a/cmd/Makefile b/cmd/Makefile index 38cb7a4aea5..0507c204c0e 100644 --- a/cmd/Makefile +++ b/cmd/Makefile @@ -69,6 +69,7 @@ obj-$(CONFIG_CMD_EEPROM) += eeprom.o obj-$(CONFIG_EFI) += efi.o efi_common.o obj-$(CONFIG_CMD_EFIDEBUG) += efidebug.o efi_common.o obj-$(CONFIG_CMD_EFICONFIG) += eficonfig.o +obj-$(CONFIG_CMD_EFI_GET_ENV) += efigetenv.o ifdef CONFIG_CMD_EFICONFIG ifdef CONFIG_EFI_MM_COMM_TEE obj-$(CONFIG_EFI_SECURE_BOOT) += eficonfig_sbkey.o diff --git a/cmd/efigetenv.c b/cmd/efigetenv.c new file mode 100644 index 00000000000..5284ee92d6c --- /dev/null +++ b/cmd/efigetenv.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0+ +#include <charset.h> +#include <command.h> +#include <efi_loader.h> +#include <efi_variable.h> +#include <env.h> +#include <hexdump.h> +#include <malloc.h> +#include <uuid.h>

+/* Set a U-Boot environment variable to the contents of a UEFI variable */ +int do_efi_get_env(struct cmd_tbl *cmdtb, int flat, int argc, char *const argv[]) +{

• u16 *var_name = NULL;
  

• char *strdata = NULL;
  

• efi_uintn_t size = 0;
  

• bool var_content_is_utf16_string = false;
  

• efi_status_t ret;
  

• efi_guid_t guid;
  

• u8 *data = NULL;
  

• u32 attributes;
  

• size_t len;
  

• u64 time;
  

• u16 *p;
  

• ret = efi_init_obj_list();
  

• if (ret != EFI_SUCCESS) {
  

•         printf("Error: Cannot initialize UEFI sub-system, r = %lu\n",
  

•                ret & ~EFI_ERROR_MASK);
  

•         return CMD_RET_FAILURE;
  

• }
  

• argv++;
  

• argc--;
  

• if (argc != 3 && argc != 4)
  

•         return CMD_RET_USAGE;
  

• if (argc == 4) {
  

•         if (strcmp(argv[0], "-s"))
  

•                 return CMD_RET_USAGE;
  

•         var_content_is_utf16_string = true;
  

•         argv++;
  

•         argc--;
  

• }
  

• len = utf8_utf16_strnlen(argv[0], strlen(argv[0]));
  

• var_name = malloc((len + 1) * 2);
  

• if (!var_name) {
  

•         printf("## Out of memory\n");
  

•         return CMD_RET_FAILURE;
  

• }
  

• p = var_name;
  

• utf8_utf16_strncpy(&p, argv[0], len + 1);
  

• if (uuid_str_to_bin(argv[1], guid.b, UUID_STR_FORMAT_GUID)) {
  

•         ret = CMD_RET_USAGE;
  

•         goto out;
  

• }
  

• ret = efi_get_variable_int(var_name, &guid, &attributes, &size, data,
  

•                            &time);
  

• if (ret == EFI_BUFFER_TOO_SMALL) {
  

•         data = malloc(size);
  

•         if (!data) {
  

•                 printf("## Out of memory\n");
  

•                 ret = CMD_RET_FAILURE;
  

•                 goto out;
  

•         }
  

•         ret = efi_get_variable_int(var_name, &guid, &attributes,
  

•                                    &size, data, &time);
  

This duplicates code in efi_dump_single_var(), do_efi_capsule_res(), get_dp_device() and others.

We should carve out a function.

That can come later. In general there are EFI_LOADER functions which could be useful in lib/efi/

Reviewed-by: Simon Glass sjg@chromium.org

Regards, Simon