[U-Boot] [PATCH v3] cmd: env: extend "env [set|print] -e" to manage UEFI variables

Heinrich Schuchardt
2019-10-05T06:53:39Z

On 10/4/19 3:20 AM, AKASHI Takahiro wrote:
> With this patch, when setting UEFI variable with "env set -e" command,
> we will be able to
> - specify vendor guid with "-guid guid",
> - specify variable attributes, BOOTSERVICE_ACCESS, RUNTIME_ACCESS,
> respectively with "-bs" and "-rt",
> - append a value instead of overwriting with "-a",
> - use memory as variable's value instead of explicit values given
> at the command line with "-i address,size"
>
> If guid is not explicitly given, default value will be used.
>
> When "-at" is given, a variable should be authenticated with
> appropriate signature database before setting or modifying its value.
> (Authentication is not supported yet though.)

Didn't you remove this in v2?

>
> Meanwhile, "env print -e," will be modified so that it will dump
> a variable's value only if '-v' (verbose) is specified.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>

This does not work as expected:

=> setenv -e -guid 0123456789abcdef0123456789abcdef -bs ARGONAUT hello world
=> printenv -e
OsIndicationsSupported:
EFI_GLOBAL_VARIABLE_GUID: BS|RT, DataSize = 0x8
PlatformLang:
EFI_GLOBAL_VARIABLE_GUID: NV|BS|RT, DataSize = 0x6
PlatformLangCodes:
EFI_GLOBAL_VARIABLE_GUID: BS|RT, DataSize = 0x6
RuntimeServicesSupported:
EFI_GLOBAL_VARIABLE_GUID: BS|RT, DataSize = 0x2

Neither do I see an error nor is the variable set.

The patch increases the size of u-boot.bin by 2216 bytes for qemu-arm64.
Tom is always asking me how we can stop the size increase in the UEFI
sub-system.

Why do we need this patch? This functionality is already available via
the UEFI shell.

Just open the UEFI shell and run

Shell> setvar ARGONAUT -guid 01234567-89ab-cdef-0123-456789abcdef -rt
=L"Hello world"
Shell> exit

Best regards

Heinrich

> ---
> Changes in v3 (Oct 4, 2019)
> * add verbose messages when SetVariable() fails
>
> Changes in v2 (Sept 6, 2019)
> * remove "-at" option
>
> ---
> cmd/nvedit.c | 19 +++--
> cmd/nvedit_efi.c | 212 +++++++++++++++++++++++++++++++++++++++--------
> 2 files changed, 190 insertions(+), 41 deletions(-)
>
> diff --git a/cmd/nvedit.c b/cmd/nvedit.c
> index 1cb0bc1460b9..1e542972db30 100644
> --- a/cmd/nvedit.c
> +++ b/cmd/nvedit.c
> @@ -1387,7 +1387,7 @@ static char env_help_text[] =
> #endif
> "env print [-a | name ...] - print environment\n"
> #if defined(CONFIG_CMD_NVEDIT_EFI)
> - "env print -e [name ...] - print UEFI environment\n"
> + "env print -e [-v] [name ...] - print UEFI environment\n"
> #endif
> #if defined(CONFIG_CMD_RUN)
> "env run var [...] - run commands in an environment variable\n"
> @@ -1399,7 +1399,8 @@ static char env_help_text[] =
> #endif
> #endif
> #if defined(CONFIG_CMD_NVEDIT_EFI)
> - "env set -e name [arg ...] - set UEFI variable; unset if 'arg' not specified\n"
> + "env set -e [-nv][-bs][-rt][-a][-i addr,size][-v] name [arg ...]\n"
> + " - set UEFI variable; unset if '-i' or 'arg' not specified\n"
> #endif
> "env set [-f] name [arg ...]\n";
> #endif
> @@ -1428,8 +1429,9 @@ U_BOOT_CMD_COMPLETE(
> "print environment variables",
> "[-a]\n - print [all] values of all environment variables\n"
> #if defined(CONFIG_CMD_NVEDIT_EFI)
> - "printenv -e [name ...]\n"
> + "printenv -e [-v] [name ...]\n"
> " - print UEFI variable 'name' or all the variables\n"
> + " \"-v\": verbose for signature database\n"
> #endif
> "printenv name ...\n"
> " - print value of environment variable 'name'",
> @@ -1459,9 +1461,16 @@ U_BOOT_CMD_COMPLETE(
> setenv, CONFIG_SYS_MAXARGS, 0, do_env_set,
> "set environment variables",
> #if defined(CONFIG_CMD_NVEDIT_EFI)
> - "-e [-nv] name [value ...]\n"
> + "-e [-guid guid][-nv][-bs][-rt][-a][-v]\n"
> + " [-i addr,size name], or [name [value ...]]\n"
> " - set UEFI variable 'name' to 'value' ...'\n"
> - " 'nv' option makes the variable non-volatile\n"
> + " \"-guid\": set vendor guid\n"
> + " \"-nv\": set non-volatile attribute\n"
> + " \"-bs\": set boot-service attribute\n"
> + " \"-rt\": set runtime attribute\n"
> + " \"-a\": append-write\n"
> + " \"-i addr,size\": use <addr,size> as variable's value\n"
> + " \"-v\": verbose print\n"
> " - delete UEFI variable 'name' if 'value' not specified\n"
> #endif
> "setenv [-f] name value ...\n"
> diff --git a/cmd/nvedit_efi.c b/cmd/nvedit_efi.c
> index ed6d09a53046..795c95be0ef7 100644
> --- a/cmd/nvedit_efi.c
> +++ b/cmd/nvedit_efi.c
> @@ -13,6 +13,7 @@
> #include <exports.h>
> #include <hexdump.h>
> #include <malloc.h>
> +#include <mapmem.h>
> #include <linux/kernel.h>
>
> /*
> @@ -34,15 +35,48 @@ static const struct {
> {EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS, "AT"},
> };
>
> +static const struct {
> + efi_guid_t guid;
> + char *text;
> +} efi_guid_text[] = {
> + /* signature database */
> + {EFI_GLOBAL_VARIABLE_GUID, "EFI_GLOBAL_VARIABLE_GUID"},
> +};
> +
> +/* "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" */
> +static char unknown_guid[37];
> +
> +/**
> + * efi_guid_to_str() - convert guid to readable name
> + *
> + * @guid: GUID
> + * Return: string for GUID
> + *
> + * convert guid to readable name
> + */
> +static const char *efi_guid_to_str(efi_guid_t *guid)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(efi_guid_text); i++)
> + if (!guidcmp(guid, &efi_guid_text[i].guid))
> + return efi_guid_text[i].text;
> +
> + uuid_bin_to_str(guid->b, unknown_guid, UUID_STR_FORMAT_GUID);
> +
> + return unknown_guid;
> +}
> +
> /**
> * efi_dump_single_var() - show information about a UEFI variable
> *
> * @name: Name of the variable
> * @guid: Vendor GUID
> + * @verbose: if true, dump data
> *
> * Show information encoded in one UEFI variable
> */
> -static void efi_dump_single_var(u16 *name, efi_guid_t *guid)
> +static void efi_dump_single_var(u16 *name, efi_guid_t *guid, bool verbose)
> {
> u32 attributes;
> u8 *data;
> @@ -68,7 +102,7 @@ static void efi_dump_single_var(u16 *name, efi_guid_t *guid)
> if (ret != EFI_SUCCESS)
> goto out;
>
> - printf("%ls:", name);
> + printf("%ls:\n %s:", name, efi_guid_to_str(guid));
> for (count = 0, i = 0; i < ARRAY_SIZE(efi_var_attrs); i++)
> if (attributes & efi_var_attrs[i].mask) {
> if (count)
> @@ -79,7 +113,9 @@ static void efi_dump_single_var(u16 *name, efi_guid_t *guid)
> puts(efi_var_attrs[i].text);
> }
> printf(", DataSize = 0x%zx\n", size);
> - print_hex_dump(" ", DUMP_PREFIX_OFFSET, 16, 1, data, size, true);
> + if (verbose)
> + print_hex_dump(" ", DUMP_PREFIX_OFFSET, 16, 1,
> + data, size, true);
>
> out:
> free(data);
> @@ -90,11 +126,12 @@ out:
> *
> * @argc: Number of arguments (variables)
> * @argv: Argument (variable name) array
> + * @verbose: if true, dump data
> * Return: CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
> *
> * Show information encoded in named UEFI variables
> */
> -static int efi_dump_vars(int argc, char * const argv[])
> +static int efi_dump_vars(int argc, char * const argv[], bool verbose)
> {
> u16 *var_name16, *p;
> efi_uintn_t buf_size, size;
> @@ -120,7 +157,8 @@ static int efi_dump_vars(int argc, char * const argv[])
> utf8_utf16_strcpy(&p, argv[0]);
>
> efi_dump_single_var(var_name16,
> - (efi_guid_t *)&efi_global_variable_guid);
> + (efi_guid_t *)&efi_global_variable_guid,
> + verbose);
> }
>
> free(var_name16);
> @@ -131,11 +169,12 @@ static int efi_dump_vars(int argc, char * const argv[])
> /**
> * efi_dump_vars() - show information about all the UEFI variables
> *
> + * @verbose: if true, dump data
> * Return: CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
> *
> * Show information encoded in all the UEFI variables
> */
> -static int efi_dump_var_all(void)
> +static int efi_dump_var_all(bool verbose)
> {
> u16 *var_name16, *p;
> efi_uintn_t buf_size, size;
> @@ -171,7 +210,7 @@ static int efi_dump_var_all(void)
> return CMD_RET_FAILURE;
> }
>
> - efi_dump_single_var(var_name16, &guid);
> + efi_dump_single_var(var_name16, &guid, verbose);
> }
>
> free(var_name16);
> @@ -189,12 +228,13 @@ static int efi_dump_var_all(void)
> * Return: CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
> *
> * This function is for "env print -e" or "printenv -e" command:
> - * => env print -e [var [...]]
> + * => env print -e [-v] [var [...]]
> * If one or more variable names are specified, show information
> * named UEFI variables, otherwise show all the UEFI variables.
> */
> int do_env_print_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> {
> + bool verbose;
> efi_status_t ret;
>
> /* Initialize EFI drivers */
> @@ -205,12 +245,23 @@ int do_env_print_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> return CMD_RET_FAILURE;
> }
>
> - if (argc > 1)
> + verbose = false;
> + for (argc--, argv++; argc > 0 && argv[0][0] == '-'; argc--, argv++) {
> + switch (argv[0][1]) {
> + case 'v':
> + verbose = true;
> + break;
> + default:
> + return CMD_RET_USAGE;
> + }
> + }
> +
> + if (argc)
> /* show specified UEFI variables */
> - return efi_dump_vars(--argc, ++argv);
> + return efi_dump_vars(argc, argv, verbose);
>
> /* enumerate and show all UEFI variables */
> - return efi_dump_var_all();
> + return efi_dump_var_all(verbose);
> }
>
> /**
> @@ -339,18 +390,22 @@ out:
> * Return: CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
> *
> * This function is for "env set -e" or "setenv -e" command:
> - * => env set -e var [value ...]]
> + * => env set -e [-guid guid][-nv][-bs][-rt][-a][-v]
> + * [-i address,size] var, or
> + * var [value ...]
> * Encode values specified and set given UEFI variable.
> * If no value is specified, delete the variable.
> */
> int do_env_set_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> {
> - char *var_name, *value = NULL;
> - efi_uintn_t size = 0;
> - u16 *var_name16 = NULL, *p;
> - size_t len;
> + char *var_name, *value, *ep;
> + ulong addr;
> + efi_uintn_t size;
> efi_guid_t guid;
> u32 attributes;
> + bool default_guid, verbose, value_on_memory;
> + u16 *var_name16 = NULL, *p;
> + size_t len;
> efi_status_t ret;
>
> if (argc == 1)
> @@ -364,32 +419,92 @@ int do_env_set_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> return CMD_RET_FAILURE;
> }
>
> - attributes = EFI_VARIABLE_BOOTSERVICE_ACCESS |
> - EFI_VARIABLE_RUNTIME_ACCESS;
> - if (!strcmp(argv[1], "-nv")) {
> - attributes |= EFI_VARIABLE_NON_VOLATILE;
> - argc--;
> - argv++;
> - if (argc == 1)
> - return CMD_RET_SUCCESS;
> + /*
> + * attributes = EFI_VARIABLE_BOOTSERVICE_ACCESS |
> + * EFI_VARIABLE_RUNTIME_ACCESS;
> + */
> + value = NULL;
> + size = 0;
> + attributes = 0;
> + guid = efi_global_variable_guid;
> + default_guid = true;
> + verbose = false;
> + value_on_memory = false;
> + for (argc--, argv++; argc > 0 && argv[0][0] == '-'; argc--, argv++) {
> + if (!strcmp(argv[0], "-guid")) {
> + if (argc == 1)
> + return CMD_RET_USAGE;
> +
> + argc--;
> + argv++;
> + if (uuid_str_to_bin(argv[0], guid.b,
> + UUID_STR_FORMAT_GUID))
> + return CMD_RET_FAILURE;
> + default_guid = false;
> + } else if (!strcmp(argv[0], "-bs")) {
> + attributes |= EFI_VARIABLE_BOOTSERVICE_ACCESS;
> + } else if (!strcmp(argv[0], "-rt")) {
> + attributes |= EFI_VARIABLE_RUNTIME_ACCESS;
> + } else if (!strcmp(argv[0], "-nv")) {
> + attributes |= EFI_VARIABLE_NON_VOLATILE;
> + } else if (!strcmp(argv[0], "-a")) {
> + attributes |= EFI_VARIABLE_APPEND_WRITE;
> + } else if (!strcmp(argv[0], "-i")) {
> + /* data comes from memory */
> + if (argc == 1)
> + return CMD_RET_USAGE;
> +
> + argc--;
> + argv++;
> + addr = simple_strtoul(argv[0], &ep, 16);
> + if (*ep != ',')
> + return CMD_RET_USAGE;
> +
> + size = simple_strtoul(++ep, NULL, 16);
> + if (!size)
> + return CMD_RET_FAILURE;
> + value_on_memory = true;
> + } else if (!strcmp(argv[0], "-v")) {
> + verbose = true;
> + } else {
> + return CMD_RET_USAGE;
> + }
> }
> + if (!argc)
> + return CMD_RET_USAGE;
> +
> + var_name = argv[0];
> + if (default_guid)
> + guid = efi_global_variable_guid;
>
> - var_name = argv[1];
> - if (argc == 2) {
> - /* delete */
> - value = NULL;
> - size = 0;
> - } else { /* set */
> - argc -= 2;
> - argv += 2;
> + if (verbose) {
> + printf("GUID: %s\n", efi_guid_to_str(&guid));
> + printf("Attributes: 0x%x\n", attributes);
> + }
>
> - for ( ; argc > 0; argc--, argv++)
> + /* for value */
> + if (value_on_memory)
> + value = map_sysmem(addr, 0);
> + else if (argc > 1)
> + for (argc--, argv++; argc > 0; argc--, argv++)
> if (append_value(&value, &size, argv[0]) < 0) {
> printf("## Failed to process an argument, %s\n",
> argv[0]);
> ret = CMD_RET_FAILURE;
> goto out;
> }
> +
> + if (size && !(attributes & (EFI_VARIABLE_BOOTSERVICE_ACCESS |
> + EFI_VARIABLE_RUNTIME_ACCESS))) {
> + printf("## Attributes (-bs or -rt) must be specified\n");
> + ret = CMD_RET_FAILURE;
> + goto out;
> + }
> +
> + if (size && verbose) {
> + printf("Value:\n");
> + print_hex_dump(" ", DUMP_PREFIX_OFFSET,
> + 16, 1, value, size, true);
> }
>
> len = utf8_utf16_strnlen(var_name, strlen(var_name));
> @@ -402,17 +517,42 @@ int do_env_set_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> p = var_name16;
> utf8_utf16_strncpy(&p, var_name, len + 1);
>
> - guid = efi_global_variable_guid;
> ret = EFI_CALL(efi_set_variable(var_name16, &guid, attributes,
> size, value));
> + unmap_sysmem(value);
> if (ret == EFI_SUCCESS) {
> ret = CMD_RET_SUCCESS;
> } else {
> - printf("## Failed to set EFI variable\n");
> + const char *msg;
> +
> + switch (ret) {
> + case EFI_NOT_FOUND:
> + msg = " (not found)";
> + break;
> + case EFI_WRITE_PROTECTED:
> + msg = " (read only)";
> + break;
> + case EFI_INVALID_PARAMETER:
> + msg = " (invalid parameter)";
> + break;
> + case EFI_SECURITY_VIOLATION:
> + msg = " (validation failed)";
> + break;
> + case EFI_OUT_OF_RESOURCES:
> + msg = " (out of memory)";
> + break;
> + default:
> + msg = "";
> + break;
> + }
> + printf("## Failed to set EFI variable%s\n", msg);
> ret = CMD_RET_FAILURE;
> }
> out:
> - free(value);
> + if (value_on_memory)
> + unmap_sysmem(value);
> + else
> + free(value);
> free(var_name16);
>
> return ret;
>