Implement a System Call Interface

Implement a system call interface simulation in C.

Requirements:

• Define SYSCALL_NUMBER enum with common syscalls (exit, write, getpid, sleep)
• Implement syscall_table as array of function pointers
• Implement syscall_handler() that dispatches based on EAX
• Simulate register state (EAX, EBX, ECX, EDX) for arguments
• Implement sys_write() that prints to console
• Implement sys_getpid() that returns current process ID
• Implement sys_sleep() that simulates yielding CPU
• Implement sys_exit() that terminates current task
• Show trap from userspace to kernel and back
• Print syscall number and arguments on each invocation
• Handle unknown syscalls with error return

Test:

• Show write syscall printing a message
• Show getpid returning a process ID
• Show exit syscall terminating a task
• Show unknown syscall returning error
• Show multiple syscalls in sequence