Merge branch '2022-01-16-bootstd-updates'

To quote the author:
So far standard boot lacks a boot menu, although it is possible to create
a rudimentary one using the existing 'bootmenu' command.

Even then, this text-based menu offer only basic functionality and does
not take full advantage of the displays which are common on many devices.

This series provides a 'bootflow menu' command which allows the user to
select from the available bootflows. An attempt is made to show the name
of the available operating systems, by reading more information into the
bootflow. A logo can be read also, where supported, so that this can be
presented to the user when an option is highlighted.

Full use is made of TrueType fonts, if enabled. For cases where only a
serial console is available, it falls back to a simple text-based menu.

All of this is implementing using a new 'expo' construct, a collection of
scenes (like menu screens) which can be navigated by the user to view
information and select options. This is fairly general and should be able
to cope with a wider array of use cases, with less hacking of the menu
code, such as is currently needed for CMD_BOOTEFI_BOOTMGR.

Of course it would be possible to enhance the existing menu rather than
creating a new setup. Instead it seems better to make the existing menu
use expo, if code space permits. It avoids the event-loop problem and
should be more extensible, given its loosely coupled components and use of
IDs instead of pointers. Further motivation is provided in the
documentation.

For now the CLI keypress-decoding code is split out to be used by the new
menu. The key codes defined by menu.h are reused also.

This is of course just a starting point. Some ideas for future work are
included in the documentation.

1 files changed, 170 insertions, 0 deletions

diff --git a/boot/expo.c b/boot/expo.c
new file mode 100644
index 0000000000..05950a1760
--- /dev/null
+++ b/boot/expo.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Implementation of a expo, a collection of scenes providing menu options
+ *
+ * Copyright 2022 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <expo.h>
+#include <malloc.h>
+#include <video.h>
+#include "scene_internal.h"
+
+int expo_new(const char *name, void *priv, struct expo **expp)
+{
+	struct expo *exp;
+
+	exp = calloc(1, sizeof(struct expo));
+	if (!exp)
+		return log_msg_ret("expo", -ENOMEM);
+	exp->name = strdup(name);
+	if (!exp->name) {
+		free(exp);
+		return log_msg_ret("name", -ENOMEM);
+	}
+	exp->priv = priv;
+	INIT_LIST_HEAD(&exp->scene_head);
+	INIT_LIST_HEAD(&exp->str_head);
+
+	*expp = exp;
+
+	return 0;
+}
+
+static void estr_destroy(struct expo_string *estr)
+{
+	free(estr);
+}
+
+void expo_destroy(struct expo *exp)
+{
+	struct scene *scn, *next;
+	struct expo_string *estr, *enext;
+
+	list_for_each_entry_safe(scn, next, &exp->scene_head, sibling)
+		scene_destroy(scn);
+
+	list_for_each_entry_safe(estr, enext, &exp->str_head, sibling)
+		estr_destroy(estr);
+
+	free(exp->name);
+	free(exp);
+}
+
+int expo_str(struct expo *exp, const char *name, uint id, const char *str)
+{
+	struct expo_string *estr;
+
+	estr = calloc(1, sizeof(struct expo_string));
+	if (!estr)
+		return log_msg_ret("obj", -ENOMEM);
+
+	estr->id = resolve_id(exp, id);
+	estr->str = str;
+	list_add_tail(&estr->sibling, &exp->str_head);
+
+	return estr->id;
+}
+
+const char *expo_get_str(struct expo *exp, uint id)
+{
+	struct expo_string *estr;
+
+	list_for_each_entry(estr, &exp->str_head, sibling) {
+		if (estr->id == id)
+			return estr->str;
+	}
+
+	return NULL;
+}
+
+int expo_set_display(struct expo *exp, struct udevice *dev)
+{
+	exp->display = dev;
+
+	return 0;
+}
+
+void exp_set_text_mode(struct expo *exp, bool text_mode)
+{
+	exp->text_mode = text_mode;
+}
+
+struct scene *expo_lookup_scene_id(struct expo *exp, uint scene_id)
+{
+	struct scene *scn;
+
+	list_for_each_entry(scn, &exp->scene_head, sibling) {
+		if (scn->id == scene_id)
+			return scn;
+	}
+
+	return NULL;
+}
+
+int expo_set_scene_id(struct expo *exp, uint scene_id)
+{
+	if (!expo_lookup_scene_id(exp, scene_id))
+		return log_msg_ret("id", -ENOENT);
+	exp->scene_id = scene_id;
+
+	return 0;
+}
+
+int expo_render(struct expo *exp)
+{
+	struct udevice *dev = exp->display;
+	struct video_priv *vid_priv = dev_get_uclass_priv(dev);
+	struct scene *scn = NULL;
+	u32 colour;
+	int ret;
+
+	colour = video_index_to_colour(vid_priv, VID_WHITE);
+	ret = video_fill(dev, colour);
+	if (ret)
+		return log_msg_ret("fill", ret);
+
+	if (exp->scene_id) {
+		scn = expo_lookup_scene_id(exp, exp->scene_id);
+		if (!scn)
+			return log_msg_ret("scn", -ENOENT);
+
+		ret = scene_render(scn);
+		if (ret)
+			return log_msg_ret("ren", ret);
+	}
+
+	video_sync(dev, true);
+
+	return scn ? 0 : -ECHILD;
+}
+
+int expo_send_key(struct expo *exp, int key)
+{
+	struct scene *scn = NULL;
+
+	if (exp->scene_id) {
+		int ret;
+
+		scn = expo_lookup_scene_id(exp, exp->scene_id);
+		if (!scn)
+			return log_msg_ret("scn", -ENOENT);
+
+		ret = scene_send_key(scn, key, &exp->action);
+		if (ret)
+			return log_msg_ret("key", ret);
+	}
+
+	return scn ? 0 : -ECHILD;
+}
+
+int expo_action_get(struct expo *exp, struct expo_action *act)
+{
+	*act = exp->action;
+	exp->action.type = EXPOACT_NONE;
+
+	return act->type == EXPOACT_NONE ? -EAGAIN : 0;
+}