provides an escape sequence from the limited "password"
strings.
+ CONFIG_AUTOBOOT_ENCRYPTION
+
+ "bootstopkeysha256" environment variable
+
+ - Hash value of the input which unlocks the device and
+ stops autoboot.
+
+ This option allows a string to be entered into U-Boot to stop the
+ autoboot. The string itself is hashed and compared against the hash
+ in the environment variable 'bootstopkeysha256'. If it matches then
+ boot stops and a command-line prompt is presented.
+
+ This provides a way to ship a secure production device which can also
+ be accessed at the U-Boot command line.
+
CONFIG_RESET_TO_RETRY
(Only effective when CONFIG_BOOT_RETRY_TIME is also set)
After the countdown timed out, the board will be reset to restart
again.
+
+ CONFIG_AUTOBOOT_USE_MENUKEY
+ CONFIG_AUTOBOOT_MENUKEY
+
+ If this key is pressed to stop autoboot, then the commands in the
+ environment variable 'menucmd' will be executed before boot starts.
+ For example, 33 means "!" in ASCII, so pressing ! at boot would take
+ this action.