2.5 Security The FreeBSD security model has been developed over 40 years of evolving application needs. The key insight is that security must be part of system design; it cannot be successfully added later. The model addresses many different goals:Support authenticated local and remote access by multiple users, as well as integration with distributed authentication and directory servicesAllow us..

Kernel Services The boundary between the kernel- and user-level code is enforced by hardware-protection facilities provided by the underlying hardware. The kernel operates in a separate address space that is inaccessible to user processes. Privileged operations—such as starting I/O and halting the central processing unit (CPU)—are available to only the kernel. Applications request services from ..

The kernel     커널이란? The kernel is the part of the system that runs in protected mode and mediates access by all user programs to the underlying hardware (e.g., CPU, keyboard, monitor, disks, network links) and software constructs (e.g., filesystem, network protocols). The kernel provides the basic system facilities; it creates and manages processes and provides functions to access the filesyste..