vbe: Add a new vbe command

Add a command to look at VBE methods and their status. Provide a test for
all of this as well.

Signed-off-by: Simon Glass <sjg@chromium.org>

cmd/Kconfig

@@ -330,6 +330,16 @@ config BOOTM_RTEMS
 	help
 	  Support booting RTEMS images via the bootm command.
 
+config CMD_VBE
+	bool "vbe - Verified Boot for Embedded"
+	depends on BOOTMETH_VBE
+	default y
+	help
+	  Provides various subcommands related to VBE, such as listing the
+	  available methods, looking at the state and changing which method
+	  is used to boot. Updating the parameters is not currently
+	  supported.
+
 config BOOTM_VXWORKS
 	bool "Support booting VxWorks OS images"
 	depends on CMD_BOOTM

cmd/Makefile

@@ -179,6 +179,7 @@ obj-$(CONFIG_CMD_FS_UUID) += fs_uuid.o
 obj-$(CONFIG_CMD_USB_MASS_STORAGE) += usb_mass_storage.o
 obj-$(CONFIG_CMD_USB_SDP) += usb_gadget_sdp.o
 obj-$(CONFIG_CMD_THOR_DOWNLOAD) += thordown.o
+obj-$(CONFIG_CMD_VBE) += vbe.o
 obj-$(CONFIG_CMD_XIMG) += ximg.o
 obj-$(CONFIG_CMD_YAFFS2) += yaffs2.o
 obj-$(CONFIG_CMD_SPL) += spl.o

cmd/vbe.c

@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Verified Boot for Embedded (VBE) command
+ *
+ * Copyright 2022 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <common.h>
+#include <bootmeth.h>
+#include <bootstd.h>
+#include <command.h>
+#include <vbe.h>
+
+static int do_vbe_list(struct cmd_tbl *cmdtp, int flag, int argc,
+		       char *const argv[])
+{
+	vbe_list();
+
+	return 0;
+}
+
+static int do_vbe_select(struct cmd_tbl *cmdtp, int flag, int argc,
+			 char *const argv[])
+{
+	struct bootstd_priv *std;
+	struct udevice *dev;
+	int ret;
+
+	ret = bootstd_get_priv(&std);
+	if (ret)
+		return CMD_RET_FAILURE;
+	if (argc < 2) {
+		std->vbe_bootmeth = NULL;
+		return 0;
+	}
+	if (vbe_find_by_any(argv[1], &dev))
+		return CMD_RET_FAILURE;
+
+	std->vbe_bootmeth = dev;
+
+	return 0;
+}
+
+static int do_vbe_info(struct cmd_tbl *cmdtp, int flag, int argc,
+		       char *const argv[])
+{
+	struct bootstd_priv *std;
+	char buf[256];
+	int ret, len;
+
+	ret = bootstd_get_priv(&std);
+	if (ret)
+		return CMD_RET_FAILURE;
+	if (!std->vbe_bootmeth) {
+		printf("No VBE bootmeth selected\n");
+		return CMD_RET_FAILURE;
+	}
+	ret = bootmeth_get_state_desc(std->vbe_bootmeth, buf, sizeof(buf));
+	if (ret) {
+		printf("Failed (err=%d)\n", ret);
+		return CMD_RET_FAILURE;
+	}
+	len = strnlen(buf, sizeof(buf));
+	if (len >= sizeof(buf)) {
+		printf("Buffer overflow\n");
+		return CMD_RET_FAILURE;
+	}
+
+	puts(buf);
+	if (buf[len] != '\n')
+		putc('\n');
+
+	return 0;
+}
+
+#ifdef CONFIG_SYS_LONGHELP
+static char vbe_help_text[] =
+	"list   - list VBE bootmeths\n"
+	"vbe select - select a VBE bootmeth by sequence or name\n"
+	"vbe info   - show information about a VBE bootmeth";
+#endif
+
+U_BOOT_CMD_WITH_SUBCMDS(vbe, "Verified Boot for Embedded", vbe_help_text,
+	U_BOOT_SUBCMD_MKENT(list, 1, 1, do_vbe_list),
+	U_BOOT_SUBCMD_MKENT(select, 2, 1, do_vbe_select),
+	U_BOOT_SUBCMD_MKENT(info, 2, 1, do_vbe_info));