Module os::syscall

Implementation of syscalls

The single entry point to all system calls, syscall(), is called whenever userspace wishes to perform a system call using the ecall instruction. In this case, the processor raises an ‘Environment call from U-mode’ exception, which is handled as one of the cases in crate::trap::trap_handler.

For clarity, each single syscall is implemented as its own function, named sys_ then the name of the syscall. You can find functions like this in submodules, and you should also implement syscalls this way.

Modules

• fs 🔒
  File and filesystem-related syscalls
• process 🔒
  Process management syscalls

Constants

• SYSCALL_EXIT 🔒
• SYSCALL_GET_TIME 🔒
• SYSCALL_WRITE 🔒
• SYSCALL_YIELD 🔒

Functions

• syscall
  handle syscall exception with syscall_id and other arguments