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

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.

Best regards

Heinrich

• }
• if (ret == EFI_NOT_FOUND) {

• printf("Error: \"%ls\" not defined\n", var_name);
  

• ret = CMD_RET_FAILURE;
  

• goto out;
  

• }
• if (ret != EFI_SUCCESS) {

• printf("Error: Cannot read variable, r = %lu\n",
  

•        ret & ~EFI_ERROR_MASK);
  

• ret = CMD_RET_FAILURE;
  

• goto out;
  

• }
• if (var_content_is_utf16_string) {

• char *p;
  

• len = utf16_utf8_strnlen((u16 *)data, size / 2);
  

• strdata = malloc(len + 1);
  

• if (!strdata) {
  

• 	printf("## Out of memory\n");
  

• 	ret = CMD_RET_FAILURE;
  

• 	goto out;
  

• }
  

• p = strdata;
  

• utf16_utf8_strncpy(&p, (u16 *)data, size / 2);
  

• } else {

• len = size * 2;
  

• strdata = malloc(len + 1);
  

• if (!strdata) {
  

• 	printf("## Out of memory\n");
  

• 	ret = CMD_RET_FAILURE;
  

• 	goto out;
  

• }
  

• bin2hex(strdata, data, size);
  

• }
• strdata[len] = '\0';
• ret = env_set(argv[2], strdata);
• if (ret) {

• ret = CMD_RET_FAILURE;
  

• goto out;
  

• }
• ret = CMD_RET_SUCCESS;

+out:

• free(strdata);
• free(data);
• free(var_name);
• return ret;

+}

+U_BOOT_CMD(

• efigetenv, 5, 4, do_efi_get_env,
• "set environment variable to content of EFI variable",
• "[-s] name guid envvar\n"
• " - set environment variable 'envvar' to the EFI variable 'name'-'guid'\n"
• " "-s": Interpret the EFI variable value as a UTF-16 string\n"

+);