- bootstrap.inc in includes/
bootstrap.inc - Functions that need to be loaded on every Backdrop request.
- drupal.inc in includes/
drupal.inc - Contains constants and function wrappers for Drupal 7.x compatibility.
- hook_requirements in modules/
system/ system.api.php - Check installation requirements and do status reporting.
- install_profile_info in includes/
install.inc - Retrieves information about an installation profile from its .info file.
- _system_rebuild_module_data in modules/
system/ system.module - Helper function to scan and collect module .info data.
- _system_rebuild_theme_data in modules/
system/ system.module - Helper function to scan and collect theme .info data and their engines.
- system_requirements in modules/
system/ system.install - Implements hook_requirements().
- update_module_add_to_system in includes/
update.inc - Adds modules to the system table in a Backdrop core update.