#include <stdio.h>

int main(void) {
    puts("OS creates process and switches to user mode");
    puts("User process runs natively");
    puts("User issues trap for restricted operation");
    puts("Hardware saves state and enters kernel mode");
    puts("Kernel handles system call then returns from trap");
    puts("User process resumes until it exits");
    puts("OS reclaims resources");
    return 0;
}