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use crate::syscall::Syscall;

#[allow(dead_code)]
/// Call into the kernel to perform a synchronous system call. The args array can be at most 6 long,
/// and the meaning of the args depends on the system call.
/// The kernel can return two 64-bit values, whose meaning depends on the system call.
///
/// You probably don't want to call this function directly, and you should instead use the wrappers
/// in [crate::syscall].
///
/// # Safety
/// The caller must ensure that the args have the correct meaning for the syscall in question, and
/// to handle the return values correctly. Additionally, calling the kernel can invoke any kind of
/// weirdness if you do something wrong.
pub unsafe fn raw_syscall(call: Syscall, args: &[u64]) -> (u64, u64) {
    if core::intrinsics::unlikely(args.len() > 6) {
        crate::print_err("too many arguments to raw_syscall");
        crate::internal_abort();
    }
    let a0 = *args.first().unwrap_or(&0u64);
    let a1 = *args.get(1).unwrap_or(&0u64);
    let mut a2 = *args.get(2).unwrap_or(&0u64);
    let a3 = *args.get(3).unwrap_or(&0u64);
    let a4 = *args.get(4).unwrap_or(&0u64);
    let a5 = *args.get(5).unwrap_or(&0u64);

    let mut num = call.num();
    core::arch::asm!("syscall", inout("rax") num, in("rdi") a0, in("rsi") a1, inout("rdx") a2, in("r10") a3, in("r9") a4, in("r8") a5, lateout("rcx") _, lateout("r11") _, clobber_abi("system"));
    (num, a2)
}