Re: [U-Boot] [PATCH v5 1/7] cmd: add efidebug command

Alex,

On Mon, Jan 21, 2019 at 02:07:31PM +0100, Alexander Graf wrote:

On 01/21/2019 08:49 AM, AKASHI Takahiro wrote:

...

Currently, there is no easy way to add or modify UEFI variables. In particular, bootmgr supports BootOrder/BootXXXX variables, it is quite hard to define them as u-boot variables because they are represented in a complicated and encoded format.

The new command, efidebug, helps address these issues and give us more friendly interfaces:

• efidebug boot add: add BootXXXX variable
• efidebug boot rm: remove BootXXXX variable
• efidebug boot dump: display all BootXXXX variables
• efidebug boot next: set BootNext variable
• efidebug boot order: set/display a boot order (BootOrder)
• efidebug setvar: set an UEFI variable (with limited functionality)
• efidebug dumpvar: display all UEFI variables

Please note that the file, efidebug.c, will be compiled under CONFIG_EFI_LOADER because some helper functions will be used to enable "env -e" command in a later patch whether or not the command is compiled in.

Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org

MAINTAINERS | 1 + cmd/Kconfig | 10 + cmd/Makefile | 1 + cmd/efidebug.c | 755 ++++++++++++++++++++++++++++++++++++++++++++++ include/command.h | 6 + 5 files changed, 773 insertions(+) create mode 100644 cmd/efidebug.c

diff --git a/MAINTAINERS b/MAINTAINERS index ae825014bda9..301c5c69ea25 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/efidebug.c F: tools/file2include.c FPGA diff --git a/cmd/Kconfig b/cmd/Kconfig index ea1a325eb301..d9cab3cc0c49 100644 --- a/cmd/Kconfig +++ b/cmd/Kconfig @@ -1397,6 +1397,16 @@ config CMD_DISPLAY displayed on a simple board-specific display. Implement display_putc() to use it. +config CMD_EFIDEBUG

• bool "efidebug - display/customize UEFI environment"
• depends on EFI_LOADER
• default n
• help

•  Enable the 'efidebug' command which provides a subset of UEFI
  

•  shell utility with simplified functionality. It will be useful
  

•  particularly for managing boot parameters as  well as examining
  

•  various EFI status for debugging.
  

config CMD_LED bool "led" default y if LED diff --git a/cmd/Makefile b/cmd/Makefile index 15ae4d250f50..e48d34c394ee 100644 --- a/cmd/Makefile +++ b/cmd/Makefile @@ -51,6 +51,7 @@ obj-$(CONFIG_CMD_ECHO) += echo.o obj-$(CONFIG_ENV_IS_IN_EEPROM) += eeprom.o obj-$(CONFIG_CMD_EEPROM) += eeprom.o obj-$(CONFIG_EFI_STUB) += efi.o +obj-$(CONFIG_EFI_LOADER) += efidebug.o obj-$(CONFIG_CMD_ELF) += elf.o obj-$(CONFIG_HUSH_PARSER) += exit.o obj-$(CONFIG_CMD_EXT4) += ext4.o diff --git a/cmd/efidebug.c b/cmd/efidebug.c new file mode 100644 index 000000000000..c54fb6cfa101 --- /dev/null +++ b/cmd/efidebug.c @@ -0,0 +1,755 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*

• • UEFI Shell-like command
• • Copyright (c) 2018 AKASHI Takahiro, Linaro Limited
• */

+#include <charset.h> +#include <common.h> +#include <command.h> +#include <efi_loader.h> +#include <environment.h> +#include <errno.h> +#include <exports.h> +#include <hexdump.h> +#include <malloc.h> +#include <search.h> +#include <linux/ctype.h> +#include <asm/global_data.h>

+static void dump_var_data(char *data, unsigned long len) +{

• char *start, *end, *p;
• unsigned long pos, count;
• char hex[3], line[9];
• int i;
• end = data + len;
• for (start = data, pos = 0; start < end; start += count, pos += count) {

• count = end - start;
  

• if (count > 16)
  

• 	count = 16;
  

• /* count should be multiple of two */
  

• printf("%08lx: ", pos);
  

• /* in hex format */
  

• p = start;
  

• for (i = 0; i < count / 2; p += 2, i++)
  

• 	printf(" %c%c", *p, *(p + 1));
  

• for (; i < 8; i++)
  

• 	printf("   ");
  

• /* in character format */
  

• p = start;
  

• hex[2] = '\0';
  

• for (i = 0; i < count / 2; i++) {
  

• 	hex[0] = *p++;
  

• 	hex[1] = *p++;
  

• 	line[i] = (char)simple_strtoul(hex, 0, 16);
  

• 	if (line[i] < 0x20 || line[i] > 0x7f)
  

• 		line[i] = '.';
  

• }
  

• line[i] = '\0';
  

• printf("  %s\n", line);
  

• }

+}

Is this print_hex_dump() reimplemented?

Actually, no. A UEFI variable on u-boot is encoded as ascii representation of binary data. That means, for example,

=> env set -e PlatformLang en => env print -e PlatformLang: {boot,run}(blob) 00000000: 65 6e en => env print ... efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_PlatformLang={boot,run}(blob)656e ...

the value of "PlatformLang" as a u-boot variable here is "656e", not "en." So if we want to use print_hex_dump(), we first have to convert that string to a binary. But then print_hex_dump() converts the binary to a string. It's just rediculuous, isn't it?

You might think that the value in this case should be {boot, run}(utf8)en ^^^^ It's possible, but it depends on a variable and currently my do_set_efi_var() doesn't support it anyway.

Thanks, -Takahiro Akashi

Alex