Module syscalls 

syscall interface: x86 convention via int80. syscall nr in rax, up to 3 parameters in rdi, rsi, rdx. Return value in rax

Constants

SYS_EXIT 🔒

SYS_WRITE 🔒

syscall numbers TODO: use a syscall loockup table

Functions

dispatch

dispatch a syscall. TODO: re-enable interrupts to make the kernel preemptive TODO: add constants for errnos

sys_exit

sys_exit(code)

sys_write^⚠

sys_write(fd, buf, len) -> number of bytes written currently only support fd==1 (stdout).