* include/grub/kernel.h (grub_module_header_types): Add type
OBJ_TYPE_CONFIG.
* kern/main.c (grub_load_config): New function.
(grub_main): Call grub_load_config to read boot config.
* grub-mkimage (generate_image): New parameter config_path.
(options): New option --config.
(main): Parse --config option, and pass it to generate_image.