[U-Boot] [PATCH v6.2] cmd: env: add "-e" option for handling UEFI variables

Heinrich Schuchardt xypron.glpk at gmx.de
Tue Feb 19 18:58:29 UTC 2019


On 2/1/19 2:31 AM, AKASHI Takahiro wrote:
> # This is a replacement of my patch#1[1] with minor updates to fix
> # travis build errors. The other patches are the exact same as in v6.
> # [1] https://lists.denx.de/pipermail/u-boot/2019-January/356035.html
> 
> "env [print|set] -e" allows for handling uefi variables without
> knowing details about mapping to corresponding u-boot variables.
> 
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>

Thanks for the patch. As long as we use U-Boot variables as backend for
EFI variables this additional functionality is very helpful.

How about adding a Python test (in a separate patch)?

When resending, please, send the complete series marked as v7 or
whatever is next.

Please, provide a change log separated via
---
from the commit message (so that it is not copied into the repository).

> ---
>  MAINTAINERS       |   1 +
>  cmd/Kconfig       |   6 +
>  cmd/Makefile      |   1 +
>  cmd/nvedit.c      |  28 +++-
>  cmd/nvedit_efi.c  | 340 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/command.h |   4 +
>  6 files changed, 379 insertions(+), 1 deletion(-)
>  create mode 100644 cmd/nvedit_efi.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index ae825014bda9..22ac686ab2d6 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -438,6 +438,7 @@ F:	lib/efi*/
>  F:	test/py/tests/test_efi*
>  F:	test/unicode_ut.c
>  F:	cmd/bootefi.c
> +F:	cmd/nvedit_efi.c
>  F:	tools/file2include.c
>  
>  FPGA
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index ea1a325eb301..c66333598d31 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -53,6 +53,12 @@ config SYS_PROMPT
>  	  This string is displayed in the command line to the left of the
>  	  cursor.
>  
> +config CMD_NVEDIT_EFI
> +	bool
> +	depends on EFI_LOADER
> +	default y
> +	imply HEXDUMP
> +

Please, add a descriptive text so that this configuration item become
editable with 'make menuconfig'.

>  menu "Autoboot options"
>  
>  config AUTOBOOT
> diff --git a/cmd/Makefile b/cmd/Makefile
> index 15ae4d250f50..142e0ee222ca 100644
> --- a/cmd/Makefile
> +++ b/cmd/Makefile
> @@ -98,6 +98,7 @@ obj-$(CONFIG_CMD_MTD) += mtd.o
>  obj-$(CONFIG_CMD_MTDPARTS) += mtdparts.o
>  obj-$(CONFIG_CMD_NAND) += nand.o
>  obj-$(CONFIG_CMD_NET) += net.o
> +obj-$(CONFIG_CMD_NVEDIT_EFI) += nvedit_efi.o
>  obj-$(CONFIG_CMD_ONENAND) += onenand.o
>  obj-$(CONFIG_CMD_OSD) += osd.o
>  obj-$(CONFIG_CMD_PART) += part.o
> diff --git a/cmd/nvedit.c b/cmd/nvedit.c
> index ce746bbf1b3e..07285b877f40 100644
> --- a/cmd/nvedit.c
> +++ b/cmd/nvedit.c
> @@ -119,6 +119,11 @@ static int do_env_print(cmd_tbl_t *cmdtp, int flag, int argc,
>  	int rcode = 0;
>  	int env_flag = H_HIDE_DOT;
>  
> +#if defined(CONFIG_CMD_NVEDIT_EFI)
> +	if (argc > 1 && argv[1][0] == '-' && argv[1][1] == 'e')
> +		return do_env_print_efi(cmdtp, flag, --argc, ++argv);
> +#endif
> +
>  	if (argc > 1 && argv[1][0] == '-' && argv[1][1] == 'a') {
>  		argc--;
>  		argv++;
> @@ -216,6 +221,12 @@ static int _do_env_set(int flag, int argc, char * const argv[], int env_flag)
>  	ENTRY e, *ep;
>  
>  	debug("Initial value for argc=%d\n", argc);
> +
> +#if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_CMD_NVEDIT_EFI)
> +	if (argc > 1 && argv[1][0] == '-' && argv[1][1] == 'e')
> +		return do_env_set_efi(NULL, flag, --argc, ++argv);
> +#endif
> +
>  	while (argc > 1 && **(argv + 1) == '-') {
>  		char *arg = *++argv;
>  
> @@ -1263,14 +1274,21 @@ static char env_help_text[] =
>  	"env import [-d] [-t [-r] | -b | -c] addr [size] [var ...] - import environment\n"
>  #endif
>  	"env print [-a | name ...] - print environment\n"
> +#if defined(CONFIG_CMD_NVEDIT_EFI)
> +	"env print  -e [name ...] - print UEFI environment\n"

There is a duplicate space before '-e'.

> +#endif
>  #if defined(CONFIG_CMD_RUN)
>  	"env run var [...] - run commands in an environment variable\n"
>  #endif
>  #if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_ENV_IS_NOWHERE)
>  	"env save - save environment\n"
>  #endif
> +#if defined(CONFIG_CMD_NVEDIT_EFI)
> +	"env set [-e | -f] name [arg ...]\n";

=> help env set
env - environment handling commands

Usage:
<snip>
env set [-e | -f] name [arg ...]

This leaves the user without a clue what env set actually does and what
-e is meant for.

Please, add a bit more text.

Wouldn't separate lines for 'set' with and without '-e' be more
consistent with what you did for 'env print'?

> +#else
>  	"env set [-f] name [arg ...]\n";

Here too.

>  #endif
> +#endif
>  
>  U_BOOT_CMD(
>  	env, CONFIG_SYS_MAXARGS, 1, do_env,
> @@ -1295,6 +1313,10 @@ U_BOOT_CMD_COMPLETE(
>  	printenv, CONFIG_SYS_MAXARGS, 1,	do_env_print,
>  	"print environment variables",
>  	"[-a]\n    - print [all] values of all environment variables\n"
> +#if defined(CONFIG_CMD_NVEDIT_EFI)
> +	"printenv -e [<name> ...]\n"
> +	"    - print UEFI variable 'name' or all the variables\n"
> +#endif
>  	"printenv name ...\n"
>  	"    - print value of environment variable 'name'",
>  	var_complete
> @@ -1322,7 +1344,11 @@ U_BOOT_CMD_COMPLETE(
>  U_BOOT_CMD_COMPLETE(
>  	setenv, CONFIG_SYS_MAXARGS, 0,	do_env_set,
>  	"set environment variables",
> -	"[-f] name value ...\n"
> +#if defined(CONFIG_CMD_NVEDIT_EFI)
> +	"-e <name> [<value> ...]\n"
> +	"    - set UEFI variable 'name' to 'value' ...'\n"
> +#endif
> +	"setenv [-f] name value ...\n"
>  	"    - [forcibly] set environment variable 'name' to 'value ...'\n"
>  	"setenv [-f] name\n"
>  	"    - [forcibly] delete environment variable 'name'",
> diff --git a/cmd/nvedit_efi.c b/cmd/nvedit_efi.c
> new file mode 100644
> index 000000000000..08a7889139e6
> --- /dev/null
> +++ b/cmd/nvedit_efi.c
> @@ -0,0 +1,340 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + *  Integrate UEFI variables to u-boot env interface
> + *
> + *  Copyright (c) 2018 AKASHI Takahiro, Linaro Limited
> + */
> +
> +#include <charset.h>
> +#include <common.h>
> +#include <command.h>
> +#include <efi_loader.h>
> +#include <exports.h>
> +#include <hexdump.h>
> +#include <malloc.h>
> +#include <linux/kernel.h>
> +
> +/*
> + * From efi_variable.c,
> + *
> + * Mapping between UEFI variables and u-boot variables:
> + *
> + *   efi_$guid_$varname = {attributes}(type)value
> + */
> +
> +static const struct {
> +	u32 mask;
> +	char *text;
> +} efi_var_attrs[] = {
> +	{EFI_VARIABLE_NON_VOLATILE, "NV"},
> +	{EFI_VARIABLE_BOOTSERVICE_ACCESS, "BS"},
> +	{EFI_VARIABLE_RUNTIME_ACCESS, "RT"},
> +	{EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS, "AW"},
> +	{EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS, "AT"},
> +};
> +
> +/* show information of named variable */

The comments for a function should look like shown below. This allows to
use Sphinx to generate a html documentation page. I prefer to add
descriptions to all functions.

/**
 * print_variable_info() - show information about a variable
 *
 * @name:	name of the variable
 * @guid:	vendor GUID
 */
> +static void print_variable_info(u16 *name, efi_guid_t *guid)
> +{
> +	u32 attributes;
> +	u8 *data;
> +	efi_uintn_t size;
> +	int count, i;
> +	efi_status_t ret;
> +
> +	data = NULL;
> +	size = 0;
> +	ret = efi_get_variable(name, guid, &attributes, &size, data);
> +	if (ret == EFI_BUFFER_TOO_SMALL) {
> +		data = malloc(size);
> +		if (!data)
> +			goto out;
> +
> +		ret = efi_get_variable(name, guid, &attributes, &size, data);
> +	}
> +	if (ret == EFI_NOT_FOUND) {
> +		printf("Error: \"%ls\" not defined\n", name);
> +		goto out;
> +	}
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	printf("%ls:", name);
> +	for (count = 0, i = 0; i < ARRAY_SIZE(efi_var_attrs); i++)
> +		if (attributes & efi_var_attrs[i].mask) {
> +			if (count)
> +				putc('|');
> +			else
> +				putc(' ');
> +			count++;
> +			puts(efi_var_attrs[i].text);
> +		}
> +	printf(", DataSize = 0x%zx\n", size);
> +	print_hex_dump("    ", DUMP_PREFIX_OFFSET, 16, 1, data, size, true);
> +
> +	return;
> +out:
> +	free(data);
> +}
> +
> +static int efi_dump_var_ones(int argc,  char * const argv[])

The naming of this function sounds strange. How about
efi_dump_single_var() or just efi_dump_var()?

> +{
> +	u16 *var_name16, *p;
> +	efi_uintn_t buf_size, size;
> +
> +	buf_size = 128;
> +	var_name16 = malloc(buf_size);
> +	if (!var_name16)
> +		return CMD_RET_FAILURE;
> +
> +	for (; argc > 0; argc--, argv++) {
> +		size = (utf8_utf16_strlen(argv[0]) + 1) * sizeof(u16);
> +		if (buf_size < size) {
> +			buf_size = size;
> +			p = realloc(var_name16, buf_size);
> +			if (!p) {
> +				free(var_name16);
> +				return CMD_RET_FAILURE;
> +			}
> +			var_name16 = p;
> +		}
> +
> +		p = var_name16;
> +		utf8_utf16_strcpy(&p, argv[0]);
> +
> +		print_variable_info(var_name16,
> +				    (efi_guid_t *)&efi_global_variable_guid);
> +	}
> +
> +	free(var_name16);
> +
> +	return CMD_RET_SUCCESS;
> +}
> +
> +static int efi_dump_var_all(void)
> +{
> +	u16 *var_name16, *p;
> +	efi_uintn_t buf_size, size;
> +	efi_guid_t guid;
> +	efi_status_t ret;
> +
> +	buf_size = 128;
> +	var_name16 = malloc(buf_size);
> +	if (!var_name16)
> +		return CMD_RET_FAILURE;
> +
> +	var_name16[0] = 0;
> +	for (;;) {
> +		size = buf_size;
> +		ret = efi_get_next_variable_name(&size, var_name16, &guid);
> +		if (ret == EFI_NOT_FOUND)
> +			break;
> +		if (ret == EFI_BUFFER_TOO_SMALL) {
> +			buf_size = size;
> +			p = realloc(var_name16, buf_size);
> +			if (!p) {
> +				free(var_name16);
> +				return CMD_RET_FAILURE;
> +			}
> +			var_name16 = p;
> +			ret = efi_get_next_variable_name(&size, var_name16,
> +							 &guid);
> +		}
> +		if (ret != EFI_SUCCESS) {
> +			free(var_name16);
> +			return CMD_RET_FAILURE;
> +		}
> +
> +		print_variable_info(var_name16, &guid);
> +	}
> +
> +	free(var_name16);
> +
> +	return CMD_RET_SUCCESS;
> +}
> +
> +static int efi_dump_var(cmd_tbl_t *cmdtp, int flag,
> +			int argc, char * const argv[])
> +{
> +	if (argc > 1)
> +		/* show specified UEFI variables */
> +		return efi_dump_var_ones(--argc, ++argv);
> +
> +	/* enumerate and show all UEFI variables */
> +	return efi_dump_var_all();
> +}
> +
> +int do_env_print_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> +{
> +	efi_status_t r;
> +
> +	/* Initialize EFI drivers */
> +	r = efi_init_obj_list();
> +	if (r != EFI_SUCCESS) {
> +		printf("Error: Cannot initialize UEFI sub-system, r = %lu\n",
> +		       r & ~EFI_ERROR_MASK);
> +		return CMD_RET_FAILURE;
> +	}
> +
> +	return efi_dump_var(cmdtp, flag, argc, argv);
> +}
> +
> +/*
> + * Interpret a given data string and append it to buffer.
> + * Buffer will be realloc'ed if necessary.
> + */

Please, use Sphinx style comment:

/**
 * append_value() - append data string to buffer
 *
 * Interpret a given data string and append it to buffer.
 * Buffer will be realloc'ed if necessary.
 *
 * @bufp:	pointer to pointer to buffer
 * @sizep:	pointer to size of buffer
 *		(updated if buffer is reallocated)
 * @data:	data to be interpreted and appended
 * Return:	0 on success
 */
> +static int append_value(char **bufp, size_t *sizep, char *data)
> +{
> +	char *tmp_buf = NULL, *new_buf = NULL, *value;
> +	unsigned long len = 0;
> +
> +	if (!strncmp(data, "=0x", 2)) { /* hexadecimal number */
> +		union {
> +			u8 u8;
> +			u16 u16;
> +			u32 u32;
> +			u64 u64;
> +		} tmp_data;
> +		unsigned long hex_value;
> +		void *hex_ptr;
> +
> +		data += 3;
> +		len = strlen(data);
> +		if ((len & 0x1)) /* not multiple of two */
> +			return -1;
> +
> +		len /= 2;
> +		if (len > 8)
> +			return -1;
> +		else if (len > 4)
> +			len = 8;
> +		else if (len > 2)
> +			len = 4;
> +
> +		/* convert hex hexadecimal number */
> +		if (strict_strtoul(data, 16, &hex_value) < 0)
> +			return -1;
> +
> +		tmp_buf = malloc(len);
> +		if (!tmp_buf)
> +			return -1;
> +
> +		if (len == 1) {
> +			tmp_data.u8 = hex_value;
> +			hex_ptr = &tmp_data.u8;
> +		} else if (len == 2) {
> +			tmp_data.u16 = hex_value;
> +			hex_ptr = &tmp_data.u16;
> +		} else if (len == 4) {
> +			tmp_data.u32 = hex_value;
> +			hex_ptr = &tmp_data.u32;
> +		} else {
> +			tmp_data.u64 = hex_value;
> +			hex_ptr = &tmp_data.u64;
> +		}
> +		memcpy(tmp_buf, hex_ptr, len);
> +		value = tmp_buf;
> +
> +	} else if (!strncmp(data, "=H", 2)) { /* hexadecimal-byte array */
> +		data += 2;
> +		len = strlen(data);
> +		if (len & 0x1) /* not multiple of two */
> +			return -1;
> +
> +		len /= 2;
> +		tmp_buf = malloc(len);
> +		if (!tmp_buf)
> +			return -1;
> +
> +		if (hex2bin((u8 *)tmp_buf, data, len) < 0)
> +			return -1;
> +
> +		value = tmp_buf;
> +	} else { /* string */
> +		if (!strncmp(data, "=\"", 2) || !strncmp(data, "=S\"", 3)) {
> +			if (data[1] == '"')
> +				data += 2;
> +			else
> +				data += 3;
> +			value = data;
> +			len = strlen(data) - 1;
> +			if (data[len] != '"')
> +				return -1;
> +		} else {
> +			value = data;
> +			len = strlen(data);
> +		}
> +	}
> +
> +	new_buf = realloc(*bufp, *sizep + len);
> +	if (!new_buf)
> +		goto out;
> +
> +	memcpy(new_buf + *sizep, value, len);
> +	*bufp = new_buf;
> +	*sizep += len;
> +
> +out:
> +	free(tmp_buf);
> +
> +	return 0;
> +}
> +
> +static int efi_set_var(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;
> +	efi_guid_t guid;
> +	efi_status_t ret;
> +
> +	if (argc == 1)
> +		return CMD_RET_SUCCESS;
> +
> +	var_name = argv[1];
> +	if (argc == 2) {
> +		/* remove */
> +		value = NULL;
> +		size = 0;
> +	} else { /* set */
> +		argc -= 2;
> +		argv += 2;
> +
> +		for ( ; argc > 0; argc--, argv++)
> +			if (append_value(&value, &size, argv[0]) < 0) {
> +				ret = CMD_RET_FAILURE;
> +				goto out;
> +			}
> +	}
> +
> +	var_name16 = malloc((strlen(var_name) + 1) * 2);

Please, always check the return value of malloc().

strlen() is the wrong function here. Use utf8_utf16_strlen() to match
the copy function below.

> +	p = var_name16;
> +	utf8_utf16_strncpy(&p, var_name, strlen(var_name) + 1);

Don't you trust your malloc() call?
Wouldn't you use utf8_utf16_strcpy()?

Best regards

Heinrich

> +
> +	guid = efi_global_variable_guid;
> +	ret = efi_set_variable(var_name16, &guid,
> +			       EFI_VARIABLE_BOOTSERVICE_ACCESS |
> +			       EFI_VARIABLE_RUNTIME_ACCESS, size, value);
> +	ret = (ret == EFI_SUCCESS ? CMD_RET_SUCCESS : CMD_RET_FAILURE);
> +out:
> +	free(value);
> +	free(var_name16);
> +
> +	return ret;
> +}
> +
> +int do_env_set_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> +{
> +	efi_status_t r;
> +
> +	/* Initialize EFI drivers */
> +	r = efi_init_obj_list();
> +	if (r != EFI_SUCCESS) {
> +		printf("Error: Cannot initialize UEFI sub-system, r = %lu\n",
> +		       r & ~EFI_ERROR_MASK);
> +		return CMD_RET_FAILURE;
> +	}
> +
> +	return efi_set_var(cmdtp, flag, argc, argv);
> +}
> diff --git a/include/command.h b/include/command.h
> index feddef300ccc..efc4dfc457c1 100644
> --- a/include/command.h
> +++ b/include/command.h
> @@ -51,6 +51,10 @@ extern int do_run(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
>  #if defined(CONFIG_CMD_BOOTEFI)
>  extern int do_bootefi_run(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
>  #endif
> +#if defined(CONFIG_CMD_NVEDIT_EFI)
> +int do_env_print_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
> +int do_env_set_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
> +#endif
>  
>  /* common/command.c */
>  int _do_help (cmd_tbl_t *cmd_start, int cmd_items, cmd_tbl_t * cmdtp, int
> 



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