xref: /kvmtool/hw/serial.c (revision 3f55f3ac72c83287bea817e87ccba1b8819447fc)
113a7760fSPekka Enberg #include "kvm/early_printk.h"
213a7760fSPekka Enberg 
313a7760fSPekka Enberg #include "kvm/ioport.h"
413a7760fSPekka Enberg 
513a7760fSPekka Enberg #include <stdio.h>
613a7760fSPekka Enberg 
7*3f55f3acSPekka Enberg static int early_serial_base = 0x3f8;  /* ttyS0 */
8*3f55f3acSPekka Enberg 
9*3f55f3acSPekka Enberg #define XMTRDY          0x20
10*3f55f3acSPekka Enberg 
11*3f55f3acSPekka Enberg #define TXR             0       /*  Transmit register (WRITE) */
12*3f55f3acSPekka Enberg #define LSR             5       /*  Line Status               */
13*3f55f3acSPekka Enberg 
1413a7760fSPekka Enberg static bool early_serial_txr_out(struct kvm *self, uint16_t port, void *data, int size, uint32_t count)
1513a7760fSPekka Enberg {
1613a7760fSPekka Enberg 	char *p = data;
1713a7760fSPekka Enberg 
1813a7760fSPekka Enberg 	printf("%c", *p);
1913a7760fSPekka Enberg 
2013a7760fSPekka Enberg 	return true;
2113a7760fSPekka Enberg }
2213a7760fSPekka Enberg 
2313a7760fSPekka Enberg static struct ioport_operations early_serial_txr_ops = {
2413a7760fSPekka Enberg 	.io_out		= early_serial_txr_out,
2513a7760fSPekka Enberg };
2613a7760fSPekka Enberg 
2713a7760fSPekka Enberg static bool early_serial_lsr_in(struct kvm *self, uint16_t port, void *data, int size, uint32_t count)
2813a7760fSPekka Enberg {
2913a7760fSPekka Enberg 	uint8_t *p = data;
3013a7760fSPekka Enberg 
31*3f55f3acSPekka Enberg 	*p	= XMTRDY;
3213a7760fSPekka Enberg 
3313a7760fSPekka Enberg 	return true;
3413a7760fSPekka Enberg }
3513a7760fSPekka Enberg 
3613a7760fSPekka Enberg static struct ioport_operations early_serial_lsr_ops = {
3713a7760fSPekka Enberg 	.io_in		= early_serial_lsr_in,
3813a7760fSPekka Enberg };
3913a7760fSPekka Enberg 
4013a7760fSPekka Enberg void early_printk__init(void)
4113a7760fSPekka Enberg {
42*3f55f3acSPekka Enberg 	ioport__register(early_serial_base + TXR, &early_serial_txr_ops);
43*3f55f3acSPekka Enberg 	ioport__register(early_serial_base + LSR, &early_serial_lsr_ops);
4413a7760fSPekka Enberg }
45