[U-Boot] [PATCH v6 1/7] cmd: env: add "-e" option for handling UEFI variables

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

On Fri, Jan 25, 2019 at 01:42:17PM +0100, Alexander Graf wrote:
> 
> 
> On 24.01.19 12:04, AKASHI Takahiro wrote:
> > "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@linaro.org>
> > ---
> >  MAINTAINERS       |   1 +
> >  cmd/Kconfig       |   6 +
> >  cmd/Makefile      |   1 +
> >  cmd/nvedit.c      |  28 +++-
> >  cmd/nvedit_efi.c  | 319 ++++++++++++++++++++++++++++++++++++++++++++++
> >  include/command.h |   4 +
> >  6 files changed, 358 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..812a7eb9b74b 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 if EFI_LOADER
> 
> No need for the "if EFI_LOADER" here. You only ever get to run the
> default path when EFI_LOADER is set due to the depends on line before.

Right.

> > +	imply HEXDUMP
> > +
> >  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..7973d7add5fc 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_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"
> > +#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";
> > +#else
> >  	"env set [-f] name [arg ...]\n";
> >  #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..58c92009e8db
> > --- /dev/null
> > +++ b/cmd/nvedit_efi.c
> > @@ -0,0 +1,319 @@
> > +// 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>
> > +
> > +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"},
> > +};
> > +
> > +static int 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)
> > +			return -1;
> 
> Just goto out.

Sure.

> > +
> > +		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%lx\n", size);
> > +	print_hex_dump("    ", DUMP_PREFIX_OFFSET, 16, 1, data, size, true);
> > +
> > +	return 0;
> > +out:
> > +	free(data);
> > +	return -1;
> > +}
> > +
> > +/*
> > + * From efi_variable.c,
> > + *
> > + * Mapping between UEFI variables and u-boot variables:
> > + *
> > + *   efi_$guid_$varname = {attributes}(type)value
> > + */
> > +static int efi_dump_var(cmd_tbl_t *cmdtp, int flag,
> > +			int argc, char * const argv[])
> > +{
> > +	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;
> > +
> > +	if (argc > 1) {
> 
> Missing a comment on what this does. Also, I think it makes sense to
> extract the 2 cases (dump 1 var, dump all vars) into separate functions.
> They share almost no code and just make indentation hard.

Okay.

> > +		argc--;
> > +		argv++;
> > +
> > +		for (; argc > 0; argc--, argv++) {
> > +			size = (strlen(argv[0]) + 1) * 2;
> 
> (utf8_utf16_strlen() + 1) * sizeof(u16)?

Okay.

> > +			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]);
> > +			guid = efi_global_variable_guid;
> 
> Why do you need to copy the guid into a stack variable? Can't you just
> pass the pointer?

You're right.

> > +
> > +			print_variable_info(var_name16, &guid);
> 
> Not checking return value?

This is in an iteration loop and the case that a variable doesn't exist
is also handled in print_variable_info(). So we don't care a return value.
I will change a return value to void to clarify this.

> > +		}
> > +
> > +		free(var_name16);
> > +
> > +		return CMD_RET_SUCCESS;
> > +	}
> > +
> > +	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);
> 
> Not checking return value?

ditto.

Unless you have any comments on other patches (than patch#1),
I'd like to send out only this one as v6.1 (or v7) since changes
here don't affect other patches.

Thanks,
-Takahiro Akashi

> 
> Alex