2.2. vortexOS kernel

vortexOS kernel

System calls are generally straightforward, sharing a similar Application Binary Interface (ABI) with standard function calls. On the x86_64 architecture, system calls are invoked using the syscall instruction, which triggers a mode switch from user-mode (ring 3) to kernel-mode (ring 0). Once the system call handler completes its operation, it switches back to user-mode, using the sysretq instruction to return control, functioning similarly to how a regular function call returns.