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, 40 insertions, 0 deletions

diff --git a/include/bootflow.h b/include/bootflow.h
index 32dbbbbe261..c201246c6de 100644
--- a/include/bootflow.h
+++ b/include/bootflow.h
@@ -7,8 +7,12 @@
 #ifndef __bootflow_h
 #define __bootflow_h
 
+#include <dm/ofnode_decl.h>
 #include <linux/list.h>
 
+struct bootstd_priv;
+struct expo;
+
 /**
  * enum bootflow_state_t - states that a particular bootflow can be in
  *
@@ -49,9 +53,13 @@ enum bootflow_state_t {
  * @state: Current state (enum bootflow_state_t)
  * @subdir: Subdirectory to fetch files from (with trailing /), or NULL if none
  * @fname: Filename of bootflow file (allocated)
+ * @logo: Logo to display for this bootflow (BMP format)
+ * @logo_size: Size of the logo in bytes
  * @buf: Bootflow file contents (allocated)
  * @size: Size of bootflow file in bytes
  * @err: Error number received (0 if OK)
+ * @os_name: Name of the OS / distro being booted, or NULL if not known
+ *	(allocated)
  */
 struct bootflow {
 	struct list_head bm_node;
@@ -65,9 +73,12 @@ struct bootflow {
 	enum bootflow_state_t state;
 	char *subdir;
 	char *fname;
+	void *logo;
+	uint logo_size;
 	char *buf;
 	int size;
 	int err;
+	char *os_name;
 };
 
 /**
@@ -329,4 +340,33 @@ int bootflow_iter_uses_network(const struct bootflow_iter *iter);
  */
 int bootflow_iter_uses_system(const struct bootflow_iter *iter);
 
+/**
+ * bootflow_menu_new() - Create a new bootflow menu
+ *
+ * @expp: Returns the expo created
+ * Returns 0 on success, -ve on error
+ */
+int bootflow_menu_new(struct expo **expp);
+
+/**
+ * bootflow_menu_apply_theme() - Apply a theme to a bootmenu
+ *
+ * @exp: Expo to update
+ * @node: Node containing the theme information
+ * Returns 0 on success, -ve on error
+ */
+int bootflow_menu_apply_theme(struct expo *exp, ofnode node);
+
+/**
+ * bootflow_menu_run() - Create and run a menu of available bootflows
+ *
+ * @std: Bootstd information
+ * @text_mode: Uses a text-based menu suitable for a serial port
+ * @bflowp: Returns chosen bootflow (set to NULL if nothing is chosen)
+ * @return 0 if an option was chosen, -EAGAIN if nothing was chosen, -ve on
+ * error
+ */
+int bootflow_menu_run(struct bootstd_priv *std, bool text_mode,
+		      struct bootflow **bflowp);
+
 #endif