User:Mna./ReactOS startup process light summary

• Freeldr loads: ROS kernel Ntoskrnl.exe, Hardware Abstraction Layer) hal.dll, language files, and registry's system hive.
• Registry:

HKEY_LOCAL_MACHINE\System contains control sets labeled ControlSet001, ControlSet002, etc., as well as CurrentControlSet. During regular operation, Windows uses CurrentControlSet to read and write information. CurrentControlSet is a reference to one of the control sets stored in the registry. Windows picks the "real" control set being used based on the values set in the HKLM\SYSTEM\Select registry key: Default will be the boot loader's choice if nothing else overrides this

• When a control set is chosen, the Current key gets set accordingly.

• Which services are started and the order each group is started are provided by the following keys:
  • HKLM\SYSTEM\CurrentControlSet\Services
  • HKLM\SYSTEM\CurrentControlSet\Control\ServiceGroupOrder

Driver loading order and types

For the purposes of booting, a driver may be one of the following:

1. A "Boot" driver that is loaded by the boot loader prior to starting the kernel. "Boot" drivers are almost exclusively drivers for hard-disk controllers and file systems (ATA, SCSI, file system filter manager, etc.); in other words, they are the absolute minimum that the kernel will need to get started with loading other drivers, and the rest of the operating system.
2. A "System" driver which is loaded and started by the kernel after the boot drivers. "System" drivers cover a wider range of core functionality, including the display driver, CD-ROM support, and the TCP/IP stack.
3. An "Automatic" driver which is loaded much later when the GUI already has been started.