Understanding Kernel Extension Symbol Resolution

The concepts included in this section explain about the kernel extension symbol resolution.

Exporting Kernel Services and System Calls
A kernel extension provides additional kernel services and system calls by specifying an export file when it is link-edited. An export file contains a list of symbols to be added to the kernel name space. In addition, symbols can be identified as system calls for 32-bit processes, 64-bit processes, or both.
Using Kernel Services
The kernel provides a set of base kernel services to be used by kernel extensions. Kernel extensions can export new kernel services, which can then be used by subsequently loaded kernel extensions.
Using System Calls with Kernel Extensions
A restricted set of system calls can be used by kernel extensions.
Using Private Routines
So far, symbol resolution for kernel extensions has been concerned with importing and exporting symbols from and to the kernel name space. Exported symbols are global in the kernel, and can be referenced by any subsequently loaded kernel extension.
Using Libraries
The operating system provides libraries that can be used by kernel extensions.

Parent topic: Kernel Environment