Merge branch '2022-04-25-initial-implementation-of-stdboot'

To quote the author:
The bootflow feature provide a built-in way for U-Boot to automatically
boot an Operating System without custom scripting and other customisation.
This is called 'standard boot' since it provides a standard way for
U-Boot to boot a distro, without scripting.

It introduces the following concepts:

   - bootdev - a device which can hold a distro
   - bootmeth - a method to scan a bootdev to find bootflows (owned by
                U-Boot)
   - bootflow - a description of how to boot (owned by the distro)

This series provides an implementation of these, enabled to scan for
bootflows from MMC, USB and Ethernet. It supports the existing distro
boot as well as the EFI loader flow (bootefi/bootmgr). It works
similiarly to the existing script-based approach, but is native to
U-Boot.

With this we can boot on a Raspberry Pi 3 with just one command:

   bootflow scan -lb

which means to scan, listing (-l) each bootflow and trying to boot each
one (-b). The final patch shows this.

With a standard way to identify boot devices, booting become easier. It
also should be possible to support U-Boot scripts, for backwards
compatibility only.

...

The design is described in these two documents:

https://drive.google.com/file/d/1ggW0KJpUOR__vBkj3l61L2dav4ZkNC12/view?usp=sharing

https://drive.google.com/file/d/1kTrflO9vvGlKp-ZH_jlgb9TY3WYG6FF9/view?usp=sharing

1 files changed, 120 insertions, 0 deletions

diff --git a/cmd/bootdev.c b/cmd/bootdev.c
new file mode 100644
index 00000000000..ecd797c0503
--- /dev/null
+++ b/cmd/bootdev.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * 'bootdev' command
+ *
+ * Copyright 2021 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <common.h>
+#include <bootdev.h>
+#include <bootflow.h>
+#include <bootstd.h>
+#include <command.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/uclass-internal.h>
+
+static int bootdev_check_state(struct bootstd_priv **stdp)
+{
+	struct bootstd_priv *std;
+	int ret;
+
+	ret = bootstd_get_priv(&std);
+	if (ret)
+		return ret;
+	if (!std->cur_bootdev) {
+		printf("Please use 'bootdev select' first\n");
+		return -ENOENT;
+	}
+	*stdp = std;
+
+	return 0;
+}
+
+static int do_bootdev_list(struct cmd_tbl *cmdtp, int flag, int argc,
+			   char *const argv[])
+{
+	bool probe;
+
+	probe = argc >= 2 && !strcmp(argv[1], "-p");
+	bootdev_list(probe);
+
+	return 0;
+}
+
+static int do_bootdev_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->cur_bootdev = NULL;
+		return 0;
+	}
+	if (bootdev_find_by_any(argv[1], &dev))
+		return CMD_RET_FAILURE;
+
+	std->cur_bootdev = dev;
+
+	return 0;
+}
+
+static int do_bootdev_info(struct cmd_tbl *cmdtp, int flag, int argc,
+			   char *const argv[])
+{
+	struct bootstd_priv *priv;
+	struct bootflow *bflow;
+	int ret, i, num_valid;
+	struct udevice *dev;
+	bool probe;
+
+	probe = argc >= 2 && !strcmp(argv[1], "-p");
+
+	ret = bootdev_check_state(&priv);
+	if (ret)
+		return CMD_RET_FAILURE;
+
+	dev = priv->cur_bootdev;
+
+	/* Count the number of bootflows, including how many are valid*/
+	num_valid = 0;
+	for (ret = bootdev_first_bootflow(dev, &bflow), i = 0;
+	     !ret;
+	     ret = bootdev_next_bootflow(&bflow), i++)
+		num_valid += bflow->state == BOOTFLOWST_READY;
+
+	/*
+	 * Prove the device, if requested, otherwise assume that there is no
+	 * error
+	 */
+	ret = 0;
+	if (probe)
+		ret = device_probe(dev);
+
+	printf("Name:      %s\n", dev->name);
+	printf("Sequence:  %d\n", dev_seq(dev));
+	printf("Status:    %s\n", ret ? simple_itoa(ret) : device_active(dev) ?
+		"Probed" : "OK");
+	printf("Uclass:    %s\n", dev_get_uclass_name(dev_get_parent(dev)));
+	printf("Bootflows: %d (%d valid)\n", i, num_valid);
+
+	return 0;
+}
+
+#ifdef CONFIG_SYS_LONGHELP
+static char bootdev_help_text[] =
+	"list [-p]      - list all available bootdevs (-p to probe)\n"
+	"bootdev select <bd>    - select a bootdev by name | label | seq\n"
+	"bootdev info [-p]      - show information about a bootdev (-p to probe)";
+#endif
+
+U_BOOT_CMD_WITH_SUBCMDS(bootdev, "Boot devices", bootdev_help_text,
+	U_BOOT_SUBCMD_MKENT(list, 2, 1, do_bootdev_list),
+	U_BOOT_SUBCMD_MKENT(select, 2, 1, do_bootdev_select),
+	U_BOOT_SUBCMD_MKENT(info, 2, 1, do_bootdev_info));