Any error opening the TCG2 protocol, reading its capability, or calling
GetActivePcrBanks aborted boot, although the value is only reported in
LoaderTpm2ActivePcrBanks. TPM firmware bugs are common, so log a
warning and report zero banks instead, as systemd-boot does.
The boot menu is now a BootMenu trait with two styles. The basic menu is
the existing one that prints entries and selects them by number. The new
simple menu is full-screen: entries are centered and highlighted, the
arrow keys, home, end, page up and page down move the selection, enter
boots it, and any key stops the countdown.
The style is picked with --menu-style or menu-style in [options], and
defaults to simple. The timer code used to wait for a key is shared
between both menus in menu.rs.
The late phase is documented to run after the entry is chosen but
before its actions are executed, but it ran before the boot menu was
shown. Run it after the entry is selected and reported to the
bootloader interface, right before executing the entry's actions.