* feat(menu): add a graphical boot menu
Adds the graphical menu style, selected with menu-style = "graphical" or
--menu-style=graphical. It draws to the graphics output with the existing
framebuffer, using a built-in 8x8 font, and takes input from the keyboard
and from relative or absolute pointers. The Sprout logo is drawn in the
bottom right corner. If there is no graphics output, the simple menu is
used, which still falls back to the basic menu.
The logo is converted from assets/logo-small.png to raw pixels by the build
crate, which adds the png crate as a build-time dependency only.
The default menu style is still simple. Pointer input is untested, as
OVMF has no mouse driver.
* fix(build): only build the logo conversion on the host
CI builds the whole workspace for the UEFI target, which also builds the
build crate for UEFI. The png dependency pulls in simd-adler32, which
crashes LLVM on that target. The logo conversion only runs in build
scripts on the host, so png and the conversion are now left out when
targeting UEFI.
RootConfiguration derived Default, which set menu-timeout to 0 and the
version to 0, while an empty configuration file gets a 10 second
timeout and the latest version. --autoconfigure uses the default
configuration, so it booted the first entry without showing the menu.
Implement Default with the same values serde uses.
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.