Hur man programmerar parallelports I/O under openbsd
/* pioexample.c Example of using PIO to talk to an I/O port
*
* Little ditty to count bits on the parallel port output register.
*/
#include <unistd.h>
#include <sys/types.h>
#include <sys/syscall.h>
#include <machine/sysarch.h>
#include <machine/pio.h>
/* ioport(port) permit access to an I/O port.
* port I/O address to enable
*/
void
ioport(int port) {
u_long iomap[32];
struct i386_set_ioperm_args ioperm;
ioperm.iomap = iomap;
syscall(SYS_sysarch, I386_GET_IOPERM, (char *) &ioperm);
iomap[port >> 5] &= ~(1 << (port & 0x1f));
syscall(SYS_sysarch, I386_SET_IOPERM, (char *) &ioperm);
}
int
main() {
int i;
ioport(0x378); /* Enable access to the port */
for(i = 0; i < 256; i++) {
outb(0x378, i); /* Set the output register */
sleep(1); /* Sleep a tick */
}
return 0;
}
Referenser till aktuell sida
grepflash - OpenBSD senast redigerad 2003-10-29 klockan 15.58 av 192.168.1.104
