Support multiple fallback entries, and provide an API to support
executing default+fallback menu entries. Renamed the `terminal' menu
viewer to `text'.
* include/grub/normal.h (grub_normal_text_menu_viewer): New global
variable declaration.
(grub_menu_execute_callback): New structure declaration.
(grub_menu_execute_callback_t): New typedef.
(grub_menu_execute_with_fallback): New function declaration.
(grub_menu_get_entry): Likewise.
(grub_menu_get_timeout): Likewise.
(grub_menu_set_timeout): Likewise.
* normal/main.c (GRUB_MOD_INIT(normal)): Refer to new variable name.
* normal/menu.c (grub_wait_after_message): Moved to
`normal/menu_text.c'.
(draw_border): Likewise.
(print_message): Likewise.
(print_entry): Likewise.
(print_entries): Likewise.
(grub_menu_init_page): Likewise.
(get_entry_number): Likewise.
(print_timeout): Likewise.
(run_menu): Likewise.
(grub_menu_execute_entry): Likewise.
(show_text_menu): Likewise.
(get_and_remove_first_entry_number): New function.
(grub_menu_execute_with_fallback): Likewise.
(get_entry): Renamed to ...
(grub_menu_get_entry): .. this and made it global.
(get_timeout): Renamed to ...
(grub_menu_get_timeout): ... this and made it global.
(set_timeout): Renamed to ...
(grub_menu_set_timeout): ... this and made it global.
(grub_normal_terminal_menu_viewer): Renamed to ...
(grub_normal_text_menu_viewer): ... this.
* normal/menu_text.c: New file. Extracted text-menu-specific code
from normal/menu.c.
* conf/i386-coreboot.rmk (grub_emu_SOURCES): Add `normal/menu_text.c'.
(normal_mod_SOURCES): Likewise.
* conf/i386-efi.rmk (grub_emu_SOURCES): Likewise.
(normal_mod_SOURCES): Likewise.
* conf/i386-ieee1275.rmk (grub_emu_SOURCES): Likewise.
(normal_mod_SOURCES): Likewise.
* conf/i386-pc.rmk, (grub_emu_SOURCES): Likewise.
(normal_mod_SOURCES): Likewise.
* conf/powerpc-ieee1275.rmk (grub_emu_SOURCES): Likewise.
(normal_mod_SOURCES): Likewise.
* conf/sparc64-ieee1275.rmk (grub_emu_SOURCES): Likewise.
(normal_mod_SOURCES): Likewise.
* conf/x86_64-efi.rmk (grub_emu_SOURCES): Likewise.
(normal_mod_SOURCES): Likewise.
