nonblocking getchar(), getting ENOMEM

I've tried implementing a nonblocking getchar() using two different methods

1) fcntl(fileno(stdin), F_SETFL, (long)O_NONBLOCK);

2) open("/dev/uart_0, O_RDWR | O_NONBLOCK);

and then use a simple read() on the fd. I would expect to have read() return -1 most times with errno set to EAGAIN. However what I am getting instead is ENOMEM (errno = 12).

I am using a basic NIOS2 on a system with 128kB of memory (implemented in M9K blocks in the EPCS4CE55I8L, no external memory). Did I miss something important either in the SOPC environment or in my BSP settings?

My function is as follows:

/* returns 1 with the character in c if a character was available, 0 otherwise */

int getchar_nonblock(int fd, char *c)

{

int ret;

ret = read(fd, c, 1);

if(ret == -1) {

if(errno == EAGAIN) return 0;

printf("? read returned -1, errno set to %i\r\n", errno);

return 0;

}

return 0;

}