#include <bits/errno-return.h>
#include <stdarg.h>
#include <stdint.h>
#include <sys/syscall.h>
#include <unistd.h>

extern "C" long arch_invoke_syscall(long, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t);

extern "C"
{
    pid_t getpid(void)
    {
        return (pid_t)syscall(SYS_getpid);
    }

    long syscall(long num, ...)
    {
        va_list ap;
        va_start(ap, num);

        uintptr_t arg0 = va_arg(ap, uintptr_t);
        uintptr_t arg1 = va_arg(ap, uintptr_t);
        uintptr_t arg2 = va_arg(ap, uintptr_t);
        uintptr_t arg3 = va_arg(ap, uintptr_t);
        uintptr_t arg4 = va_arg(ap, uintptr_t);

        long rc = arch_invoke_syscall(num, arg0, arg1, arg2, arg3, arg4);

        va_end(ap);

        return rc;
    }

    int usleep(useconds_t us)
    {
        long rc = syscall(SYS_usleep, us);
        __errno_return(rc, int);
    }

    unsigned long sleep(unsigned long seconds)
    {
        syscall(SYS_usleep, seconds * 1000000);
        return 0;
    }

    int close(int fd)
    {
        long rc = syscall(SYS_close, fd);
        __errno_return(rc, int);
    }

    ssize_t read(int fd, void* buf, size_t size)
    {
        long rc = syscall(SYS_read, fd, buf, size);
        __errno_return(rc, ssize_t);
    }

    ssize_t write(int fd, const void* buf, size_t size)
    {
        long rc = syscall(SYS_write, fd, buf, size);
        __errno_return(rc, ssize_t);
    }
}