Provide opinionated boot flow

It would be preferrable to read linux,default-trigger or u-boot,default-trigger
instead of adding `setup_leds` to the env.

Author: samueldr

include/config_distro_bootcmd.h

@@ -9,6 +9,8 @@
 #ifndef _CONFIG_CMD_DISTRO_BOOTCMD_H
 #define _CONFIG_CMD_DISTRO_BOOTCMD_H
 
+#include <tow-boot_env.h>
+
 /*
  * A note on error handling: It is possible for BOOT_TARGET_DEVICES to
  * reference a device that is not enabled in the U-Boot configuration, e.g.
@@ -538,6 +540,8 @@
 		BOOTENV_SET_EXTENSION_NEED_INIT                           \
 		"for target in ${boot_targets}; do "                      \
 			"run bootcmd_${target}; "                         \
-		"done\0"
+		"done\0" \
+	\
+	TOW_BOOT_ENV
 
 #endif  /* _CONFIG_CMD_DISTRO_BOOTCMD_H */

include/tow-boot_env.h

@@ -0,0 +1,58 @@
+#ifndef _TOW_BOOT_ENV_H
+#define _TOW_BOOT_ENV_H
+
+#ifdef CONFIG_CMD_POWEROFF
+#define TOW_BOOT_MAYBE_POWEROFF "tb_menu add 'Shutdown' 'Powers off the device' 'poweroff';"
+#else
+#define TOW_BOOT_MAYBE_POWEROFF
+#endif
+
+#ifdef CONFIG_CMD_USB
+#define TOW_BOOT_MAYBE_USB "tb_menu add 'Rescan USB' 'Look for new USB devices' \"usb reset; $menucmd\";"
+#else
+#define TOW_BOOT_MAYBE_USB
+#endif
+
+#define TOW_BOOT_ENV \
+	/* Used internally to check updater runs on the right board. */ \
+	"board_identifier=@boardIdentifier@\0" \
+	\
+	/* By default, no setup for LEDs */ \
+	"setup_leds=echo\0" \
+	"bootcmd=run setup_leds; run distro_bootcmd\0" \
+	"target_name_mmc0=" CONFIG_TOW_BOOT_MMC0_NAME "\0" \
+	"target_name_mmc1=" CONFIG_TOW_BOOT_MMC1_NAME "\0" \
+	"target_name_mmc2=" CONFIG_TOW_BOOT_MMC2_NAME "\0" \
+	"target_name_usb0=USB\0" \
+	"target_name_nvme0=NVME\0" \
+	"target_name_pxe=PXE\0" \
+	"target_name_dhcp=DHCP\0" \
+	\
+	\
+	"towboot_menu=" \
+	/* Builds the boot options in the same order distro_bootcmd uses. */ \
+	"tb_menu new;" \
+	"for target in ${boot_targets}; do" \
+	/*   # Skip fel as it has no value for end-users */ \
+	"    if test \"$target\" != fel; then" \
+	"        env indirect target_name target_name_${target} \"(${target})\";" \
+	"        tb_menu add \"Boot from ${target_name}\" '' \"run bootcmd_${target}; echo ${target_name} Boot failed.; pause; $menucmd\" ;" \
+	"    fi;" \
+	"done;" \
+	\
+	"tb_menu separator;" \
+	TOW_BOOT_MAYBE_USB \
+	/* In the future, this would be "Firmware Options". */ \
+	"tb_menu add 'Firmware Console' 'Go to the console' 'cls; echo; echo \"Use `run menucmd` to return to the menu.\" ; echo' ;" \
+	"tb_menu separator;" \
+	/* `reset` is universal. Power off is optional */ \
+	"tb_menu add 'Reboot' 'Reboots the device' 'reset';" \
+	TOW_BOOT_MAYBE_POWEROFF \
+	/* Show this menu! */ \
+	"tb_menu show" \
+	"\0" \
+	\
+	\
+	"menucmd=run towboot_menu\0" \
+
+#endif