cmd: add efidebug command

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)

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

3 files changed, 598 insertions, 0 deletions

diff --git a/cmd/Kconfig b/cmd/Kconfig
index af2bfb4e58..4bcc5c4557 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1407,6 +1407,16 @@ config CMD_DISPLAY
 	  displayed on a simple board-specific display. Implement
 	  display_putc() to use it.
 
+config CMD_EFIDEBUG
+	bool "efidebug - display/configure 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"
 	depends on LED
diff --git a/cmd/Makefile b/cmd/Makefile
index b9ee51869d..acb85f49fb 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-$(CONFIG_CMD_EFIDEBUG) += efidebug.o
 obj-$(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 0000000000..a1e0832bc4
--- /dev/null
+++ b/cmd/efidebug.c
@@ -0,0 +1,587 @@
+// 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 <exports.h>
+#include <malloc.h>
+#include <search.h>
+#include <linux/ctype.h>
+
+#define RT systab.runtime
+
+/**
+ * do_efi_boot_add() - set UEFI load option
+ *
+ * @cmdtp:	Command table
+ * @flag:	Command flag
+ * @argc:	Number of arguments
+ * @argv:	Argument array
+ * Return:	CMD_RET_SUCCESS on success,
+ *		CMD_RET_USAGE or CMD_RET_RET_FAILURE on failure
+ *
+ * Implement efidebug "boot add" sub-command.
+ * Create or change UEFI load option.
+ *   - boot add <id> <label> <interface> <devnum>[:<part>] <file> <options>
+ */
+static int do_efi_boot_add(cmd_tbl_t *cmdtp, int flag,
+			   int argc, char * const argv[])
+{
+	int id;
+	char *endp;
+	char var_name[9];
+	u16 var_name16[9], *p;
+	efi_guid_t guid;
+	size_t label_len, label_len16;
+	u16 *label;
+	struct efi_device_path *device_path = NULL, *file_path = NULL;
+	struct efi_load_option lo;
+	void *data = NULL;
+	efi_uintn_t size;
+	int ret;
+
+	if (argc < 6 || argc > 7)
+		return CMD_RET_USAGE;
+
+	id = (int)simple_strtoul(argv[1], &endp, 16);
+	if (*endp != '\0' || id > 0xffff)
+		return CMD_RET_FAILURE;
+
+	sprintf(var_name, "Boot%04X", id);
+	p = var_name16;
+	utf8_utf16_strncpy(&p, var_name, 9);
+
+	guid = efi_global_variable_guid;
+
+	/* attributes */
+	lo.attributes = LOAD_OPTION_ACTIVE; /* always ACTIVE */
+
+	/* label */
+	label_len = strlen(argv[2]);
+	label_len16 = utf8_utf16_strnlen(argv[2], label_len);
+	label = malloc((label_len16 + 1) * sizeof(u16));
+	if (!label)
+		return CMD_RET_FAILURE;
+	lo.label = label; /* label will be changed below */
+	utf8_utf16_strncpy(&label, argv[2], label_len);
+
+	/* file path */
+	ret = efi_dp_from_name(argv[3], argv[4], argv[5], &device_path,
+			       &file_path);
+	if (ret != EFI_SUCCESS) {
+		printf("Cannot create device path for \"%s %s\"\n",
+		       argv[3], argv[4]);
+		ret = CMD_RET_FAILURE;
+		goto out;
+	}
+	lo.file_path = file_path;
+	lo.file_path_length = efi_dp_size(file_path)
+				+ sizeof(struct efi_device_path); /* for END */
+
+	/* optional data */
+	lo.optional_data = (u8 *)(argc == 6 ? "" : argv[6]);
+
+	size = efi_serialize_load_option(&lo, (u8 **)&data);
+	if (!size) {
+		ret = CMD_RET_FAILURE;
+		goto out;
+	}
+
+	ret = EFI_CALL(RT->set_variable(var_name16, &guid,
+					EFI_VARIABLE_BOOTSERVICE_ACCESS |
+					EFI_VARIABLE_RUNTIME_ACCESS,
+					size, data));
+	ret = (ret == EFI_SUCCESS ? CMD_RET_SUCCESS : CMD_RET_FAILURE);
+out:
+	free(data);
+	efi_free_pool(device_path);
+	efi_free_pool(file_path);
+	free(lo.label);
+
+	return ret;
+}
+
+/**
+ * do_efi_boot_rm() - delete UEFI load options
+ *
+ * @cmdtp:	Command table
+ * @flag:	Command flag
+ * @argc:	Number of arguments
+ * @argv:	Argument array
+ * Return:	CMD_RET_SUCCESS on success, CMD_RET_RET_FAILURE on failure
+ *
+ * Implement efidebug "boot rm" sub-command.
+ * Delete UEFI load options.
+ *   - boot rm <id> ...
+ */
+static int do_efi_boot_rm(cmd_tbl_t *cmdtp, int flag,
+			  int argc, char * const argv[])
+{
+	efi_guid_t guid;
+	int id, i;
+	char *endp;
+	char var_name[9];
+	u16 var_name16[9];
+	efi_status_t ret;
+
+	if (argc == 1)
+		return CMD_RET_USAGE;
+
+	guid = efi_global_variable_guid;
+	for (i = 1; i < argc; i++, argv++) {
+		id = (int)simple_strtoul(argv[1], &endp, 16);
+		if (*endp != '\0' || id > 0xffff)
+			return CMD_RET_FAILURE;
+
+		sprintf(var_name, "Boot%04X", id);
+		utf8_utf16_strncpy((u16 **)&var_name16, var_name, 9);
+
+		ret = EFI_CALL(RT->set_variable(var_name16, &guid, 0, 0, NULL));
+		if (ret) {
+			printf("cannot remove Boot%04X", id);
+			return CMD_RET_FAILURE;
+		}
+	}
+
+	return CMD_RET_SUCCESS;
+}
+
+/**
+ * show_efi_boot_opt_data() - dump UEFI load option
+ *
+ * @id:		Load option number
+ * @data:	Value of UEFI load option variable
+ *
+ * Decode the value of UEFI load option variable and print information.
+ */
+static void show_efi_boot_opt_data(int id, void *data)
+{
+	struct efi_load_option lo;
+	char *label, *p;
+	size_t label_len16, label_len;
+	u16 *dp_str;
+
+	efi_deserialize_load_option(&lo, data);
+
+	label_len16 = u16_strlen(lo.label);
+	label_len = utf16_utf8_strnlen(lo.label, label_len16);
+	label = malloc(label_len + 1);
+	if (!label)
+		return;
+	p = label;
+	utf16_utf8_strncpy(&p, lo.label, label_len16);
+
+	printf("Boot%04X:\n", id);
+	printf("\tattributes: %c%c%c (0x%08x)\n",
+	       /* ACTIVE */
+	       lo.attributes & LOAD_OPTION_ACTIVE ? 'A' : '-',
+	       /* FORCE RECONNECT */
+	       lo.attributes & LOAD_OPTION_FORCE_RECONNECT ? 'R' : '-',
+	       /* HIDDEN */
+	       lo.attributes & LOAD_OPTION_HIDDEN ? 'H' : '-',
+	       lo.attributes);
+	printf("\tlabel: %s\n", label);
+
+	dp_str = efi_dp_str(lo.file_path);
+	printf("\tfile_path: %ls\n", dp_str);
+	efi_free_pool(dp_str);
+
+	printf("\tdata: %s\n", lo.optional_data);
+
+	free(label);
+}
+
+/**
+ * show_efi_boot_opt() - dump UEFI load option
+ *
+ * @id:		Load option number
+ *
+ * Dump information defined by UEFI load option.
+ */
+static void show_efi_boot_opt(int id)
+{
+	char var_name[9];
+	u16 var_name16[9], *p;
+	efi_guid_t guid;
+	void *data = NULL;
+	efi_uintn_t size;
+	int ret;
+
+	sprintf(var_name, "Boot%04X", id);
+	p = var_name16;
+	utf8_utf16_strncpy(&p, var_name, 9);
+	guid = efi_global_variable_guid;
+
+	size = 0;
+	ret = EFI_CALL(RT->get_variable(var_name16, &guid, NULL, &size, NULL));
+	if (ret == (int)EFI_BUFFER_TOO_SMALL) {
+		data = malloc(size);
+		ret = EFI_CALL(RT->get_variable(var_name16, &guid, NULL, &size,
+						data));
+	}
+	if (ret == EFI_SUCCESS)
+		show_efi_boot_opt_data(id, data);
+	else if (ret == EFI_NOT_FOUND)
+		printf("Boot%04X: not found\n", id);
+
+	free(data);
+}
+
+/**
+ * show_efi_boot_dump() - dump all UEFI load options
+ *
+ * @cmdtp:	Command table
+ * @flag:	Command flag
+ * @argc:	Number of arguments
+ * @argv:	Argument array
+ * Return:	CMD_RET_SUCCESS on success, CMD_RET_RET_FAILURE on failure
+ *
+ * Implement efidebug "boot dump" sub-command.
+ * Dump information of all UEFI load options defined.
+ *   - boot dump
+ */
+static int do_efi_boot_dump(cmd_tbl_t *cmdtp, int flag,
+			    int argc, char * const argv[])
+{
+	char regex[256];
+	char * const regexlist[] = {regex};
+	char *variables = NULL, *boot, *value;
+	int len;
+	int id;
+
+	if (argc > 1)
+		return CMD_RET_USAGE;
+
+	snprintf(regex, 256, "efi_.*-.*-.*-.*-.*_Boot[0-9A-F]+");
+
+	/* TODO: use GetNextVariableName? */
+	len = hexport_r(&env_htab, '\n', H_MATCH_REGEX | H_MATCH_KEY,
+			&variables, 0, 1, regexlist);
+
+	if (!len)
+		return CMD_RET_SUCCESS;
+
+	if (len < 0)
+		return CMD_RET_FAILURE;
+
+	boot = variables;
+	while (*boot) {
+		value = strstr(boot, "Boot") + 4;
+		id = (int)simple_strtoul(value, NULL, 16);
+		show_efi_boot_opt(id);
+		boot = strchr(boot, '\n');
+		if (!*boot)
+			break;
+		boot++;
+	}
+	free(variables);
+
+	return CMD_RET_SUCCESS;
+}
+
+/**
+ * show_efi_boot_order() - show order of UEFI load options
+ *
+ * Return:	CMD_RET_SUCCESS on success, CMD_RET_RET_FAILURE on failure
+ *
+ * Show order of UEFI load options defined by BootOrder variable.
+ */
+static int show_efi_boot_order(void)
+{
+	efi_guid_t guid;
+	u16 *bootorder = NULL;
+	efi_uintn_t size;
+	int num, i;
+	char var_name[9];
+	u16 var_name16[9], *p16;
+	void *data;
+	struct efi_load_option lo;
+	char *label, *p;
+	size_t label_len16, label_len;
+	efi_status_t ret;
+
+	guid = efi_global_variable_guid;
+	size = 0;
+	ret = EFI_CALL(RT->get_variable(L"BootOrder", &guid, NULL, &size,
+					NULL));
+	if (ret == EFI_BUFFER_TOO_SMALL) {
+		bootorder = malloc(size);
+		ret = EFI_CALL(RT->get_variable(L"BootOrder", &guid, NULL,
+						&size, bootorder));
+	}
+	if (ret == EFI_NOT_FOUND) {
+		printf("BootOrder not defined\n");
+		ret = CMD_RET_SUCCESS;
+		goto out;
+	} else if (ret != EFI_SUCCESS) {
+		ret = CMD_RET_FAILURE;
+		goto out;
+	}
+
+	num = size / sizeof(u16);
+	for (i = 0; i < num; i++) {
+		sprintf(var_name, "Boot%04X", bootorder[i]);
+		p16 = var_name16;
+		utf8_utf16_strncpy(&p16, var_name, 9);
+
+		size = 0;
+		ret = EFI_CALL(RT->get_variable(var_name16, &guid, NULL, &size,
+						NULL));
+		if (ret != EFI_BUFFER_TOO_SMALL) {
+			printf("%2d: Boot%04X: (not defined)\n",
+			       i + 1, bootorder[i]);
+			continue;
+		}
+
+		data = malloc(size);
+		if (!data) {
+			ret = CMD_RET_FAILURE;
+			goto out;
+		}
+		ret = EFI_CALL(RT->get_variable(var_name16, &guid, NULL, &size,
+						data));
+		if (ret != EFI_SUCCESS) {
+			free(data);
+			ret = CMD_RET_FAILURE;
+			goto out;
+		}
+
+		efi_deserialize_load_option(&lo, data);
+
+		label_len16 = u16_strlen(lo.label);
+		label_len = utf16_utf8_strnlen(lo.label, label_len16);
+		label = malloc(label_len + 1);
+		if (!label) {
+			free(data);
+			ret = CMD_RET_FAILURE;
+			goto out;
+		}
+		p = label;
+		utf16_utf8_strncpy(&p, lo.label, label_len16);
+		printf("%2d: Boot%04X: %s\n", i + 1, bootorder[i], label);
+		free(label);
+
+		free(data);
+	}
+out:
+	free(bootorder);
+
+	return ret;
+}
+
+/**
+ * do_efi_boot_next() - manage UEFI BootNext variable
+ *
+ * @cmdtp:	Command table
+ * @flag:	Command flag
+ * @argc:	Number of arguments
+ * @argv:	Argument array
+ * Return:	CMD_RET_SUCCESS on success,
+ *		CMD_RET_USAGE or CMD_RET_RET_FAILURE on failure
+ *
+ * Implement efidebug "boot next" sub-command.
+ * Set BootNext variable.
+ *   - boot next <id>
+ */
+static int do_efi_boot_next(cmd_tbl_t *cmdtp, int flag,
+			    int argc, char * const argv[])
+{
+	u16 bootnext;
+	efi_uintn_t size;
+	char *endp;
+	efi_guid_t guid;
+	efi_status_t ret;
+
+	if (argc != 2)
+		return CMD_RET_USAGE;
+
+	bootnext = (u16)simple_strtoul(argv[1], &endp, 16);
+	if (*endp != '\0' || bootnext > 0xffff) {
+		printf("invalid value: %s\n", argv[1]);
+		ret = CMD_RET_FAILURE;
+		goto out;
+	}
+
+	guid = efi_global_variable_guid;
+	size = sizeof(u16);
+	ret = EFI_CALL(RT->set_variable(L"BootNext", &guid,
+					EFI_VARIABLE_BOOTSERVICE_ACCESS |
+					EFI_VARIABLE_RUNTIME_ACCESS,
+					size, &bootnext));
+	ret = (ret == EFI_SUCCESS ? CMD_RET_SUCCESS : CMD_RET_FAILURE);
+out:
+	return ret;
+}
+
+/**
+ * do_efi_boot_order() - manage UEFI BootOrder variable
+ *
+ * @cmdtp:	Command table
+ * @flag:	Command flag
+ * @argc:	Number of arguments
+ * @argv:	Argument array
+ * Return:	CMD_RET_SUCCESS on success, CMD_RET_RET_FAILURE on failure
+ *
+ * Implement efidebug "boot order" sub-command.
+ * Show order of UEFI load options, or change it in BootOrder variable.
+ *   - boot order [<id> ...]
+ */
+static int do_efi_boot_order(cmd_tbl_t *cmdtp, int flag,
+			     int argc, char * const argv[])
+{
+	u16 *bootorder = NULL;
+	efi_uintn_t size;
+	int id, i;
+	char *endp;
+	efi_guid_t guid;
+	efi_status_t ret;
+
+	if (argc == 1)
+		return show_efi_boot_order();
+
+	argc--;
+	argv++;
+
+	size = argc * sizeof(u16);
+	bootorder = malloc(size);
+	if (!bootorder)
+		return CMD_RET_FAILURE;
+
+	for (i = 0; i < argc; i++) {
+		id = (int)simple_strtoul(argv[i], &endp, 16);
+		if (*endp != '\0' || id > 0xffff) {
+			printf("invalid value: %s\n", argv[i]);
+			ret = CMD_RET_FAILURE;
+			goto out;
+		}
+
+		bootorder[i] = (u16)id;
+	}
+
+	guid = efi_global_variable_guid;
+	ret = EFI_CALL(RT->set_variable(L"BootOrder", &guid,
+					EFI_VARIABLE_BOOTSERVICE_ACCESS |
+					EFI_VARIABLE_RUNTIME_ACCESS,
+					size, bootorder));
+	ret = (ret == EFI_SUCCESS ? CMD_RET_SUCCESS : CMD_RET_FAILURE);
+out:
+	free(bootorder);
+
+	return ret;
+}
+
+static cmd_tbl_t cmd_efidebug_boot_sub[] = {
+	U_BOOT_CMD_MKENT(add, CONFIG_SYS_MAXARGS, 1, do_efi_boot_add, "", ""),
+	U_BOOT_CMD_MKENT(rm, CONFIG_SYS_MAXARGS, 1, do_efi_boot_rm, "", ""),
+	U_BOOT_CMD_MKENT(dump, CONFIG_SYS_MAXARGS, 1, do_efi_boot_dump, "", ""),
+	U_BOOT_CMD_MKENT(next, CONFIG_SYS_MAXARGS, 1, do_efi_boot_next, "", ""),
+	U_BOOT_CMD_MKENT(order, CONFIG_SYS_MAXARGS, 1, do_efi_boot_order,
+			 "", ""),
+};
+
+/**
+ * do_efi_boot_opt() - manage UEFI load options
+ *
+ * @cmdtp:	Command table
+ * @flag:	Command flag
+ * @argc:	Number of arguments
+ * @argv:	Argument array
+ * Return:	CMD_RET_SUCCESS on success,
+ *		CMD_RET_USAGE or CMD_RET_RET_FAILURE on failure
+ *
+ * Implement efidebug "boot" sub-command.
+ * See above for details of sub-commands.
+ */
+static int do_efi_boot_opt(cmd_tbl_t *cmdtp, int flag,
+			   int argc, char * const argv[])
+{
+	cmd_tbl_t *cp;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+
+	argc--; argv++;
+
+	cp = find_cmd_tbl(argv[0], cmd_efidebug_boot_sub,
+			  ARRAY_SIZE(cmd_efidebug_boot_sub));
+	if (!cp)
+		return CMD_RET_USAGE;
+
+	return cp->cmd(cmdtp, flag, argc, argv);
+}
+
+static cmd_tbl_t cmd_efidebug_sub[] = {
+	U_BOOT_CMD_MKENT(boot, CONFIG_SYS_MAXARGS, 1, do_efi_boot_opt, "", ""),
+};
+
+/**
+ * do_efidebug() - display and configure UEFI environment
+ *
+ * @cmdtp:	Command table
+ * @flag:	Command flag
+ * @argc:	Number of arguments
+ * @argv:	Argument array
+ * Return:	CMD_RET_SUCCESS on success,
+ *		CMD_RET_USAGE or CMD_RET_RET_FAILURE on failure
+ *
+ * Implement efidebug command which allows us to display and
+ * configure UEFI environment.
+ * See above for details of sub-commands.
+ */
+static int do_efidebug(cmd_tbl_t *cmdtp, int flag,
+		       int argc, char * const argv[])
+{
+	cmd_tbl_t *cp;
+	efi_status_t r;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+
+	argc--; argv++;
+
+	/* Initialize UEFI 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;
+	}
+
+	cp = find_cmd_tbl(argv[0], cmd_efidebug_sub,
+			  ARRAY_SIZE(cmd_efidebug_sub));
+	if (!cp)
+		return CMD_RET_USAGE;
+
+	return cp->cmd(cmdtp, flag, argc, argv);
+}
+
+#ifdef CONFIG_SYS_LONGHELP
+static char efidebug_help_text[] =
+	"  - UEFI Shell-like interface to configure UEFI environment\n"
+	"\n"
+	"efidebug boot add <bootid> <label> <interface> <devnum>[:<part>] <file path> [<load options>]\n"
+	"  - set UEFI BootXXXX variable\n"
+	"    <load options> will be passed to UEFI application\n"
+	"efidebug boot rm <bootid#1> [<bootid#2> [<bootid#3> [...]]]\n"
+	"  - delete UEFI BootXXXX variables\n"
+	"efidebug boot dump\n"
+	"  - dump all UEFI BootXXXX variables\n"
+	"efidebug boot next <bootid>\n"
+	"  - set UEFI BootNext variable\n"
+	"efidebug boot order [<bootid#1> [<bootid#2> [<bootid#3> [...]]]]\n"
+	"  - set/show UEFI boot order\n"
+	"\n";
+#endif
+
+U_BOOT_CMD(
+	efidebug, 10, 0, do_efidebug,
+	"Configure UEFI environment",
+	efidebug_help_text
+);