FreeVMS uses special bootloader that follows multiboot specifications as FreeVMS server does not contain any driver to access to its root device.
In a first time, bootloader load in memory:
- L4/X2 microkernel;
- FreeVMS server (L4/X2 root task) followed by some options (root device, debug options...);
- minimal drivers that allow FreeVMS server to mount its root device.
When root device is mounted, kernel tries to read SYS$ROOT:[SYSMGR]VMSKERNEL.CNF and directly loads all other drivers from disk.
SYS$ROOT:[SYSMGR]SYSTARTUP.COM is read after complete drivers initialization.