struct consfront_dev *init_consfront(char *_nodename)
{
xenbus_transaction_t xbt;
char* err;
char* message=NULL;
int retry=0;
char* msg = NULL;
char nodename[256];
char path[256];
static int consfrontends = 3;
struct consfront_dev *dev;
int res;
if (!_nodename)
snprintf(nodename, sizeof(nodename), "device/console/%d", consfrontends);
else
strncpy(nodename, _nodename, sizeof(nodename));
printk("******************* CONSFRONT for %s **********\n\n\n", nodename);
consfrontends++;
dev = malloc(sizeof(*dev));
memset(dev, 0, sizeof(*dev));
dev->nodename = strdup(nodename);
#ifdef HAVE_LIBC
dev->fd = -1;
#endif
snprintf(path, sizeof(path), "%s/backend-id", nodename);
if ((res = xenbus_read_integer(path)) < 0)
return NULL;
else
dev->dom = res;
evtchn_alloc_unbound(dev->dom, handle_input, dev, &dev->evtchn);
dev->ring = (struct xencons_interface *) alloc_page();
memset(dev->ring, 0, PAGE_SIZE);
dev->ring_ref = gnttab_grant_access(dev->dom, virt_to_mfn(dev->ring), 0);
dev->events = NULL;
again:
err = xenbus_transaction_start(&xbt);
if (err) {
printk("starting transaction\n");
free(err);
}
err = xenbus_printf(xbt, nodename, "ring-ref","%u",
dev->ring_ref);
if (err) {
message = "writing ring-ref";
goto abort_transaction;
}
err = xenbus_printf(xbt, nodename,
"port", "%u", dev->evtchn);
if (err) {
message = "writing event-channel";
goto abort_transaction;
}
err = xenbus_printf(xbt, nodename,
"protocol", "%s", XEN_IO_PROTO_ABI_NATIVE);
if (err) {
message = "writing protocol";
goto abort_transaction;
}
err = xenbus_printf(xbt, nodename, "type", "%s", "ioemu");
if (err) {
message = "writing type";
goto abort_transaction;
}
snprintf(path, sizeof(path), "%s/state", nodename);
err = xenbus_switch_state(xbt, path, XenbusStateConnected);
if (err) {
message = "switching state";
goto abort_transaction;
}
err = xenbus_transaction_end(xbt, 0, &retry);
if (err) free(err);
if (retry) {
goto again;
printk("completing transaction\n");
}
goto done;
abort_transaction:
free(err);
err = xenbus_transaction_end(xbt, 1, &retry);
goto error;
done:
snprintf(path, sizeof(path), "%s/backend", nodename);
msg = xenbus_read(XBT_NIL, path, &dev->backend);
if (msg) {
printk("Error %s when reading the backend path %s\n", msg, path);
goto error;
}
printk("backend at %s\n", dev->backend);
{
XenbusState state;
char path[strlen(dev->backend) + 1 + 19 + 1];
snprintf(path, sizeof(path), "%s/state", dev->backend);
xenbus_watch_path_token(XBT_NIL, path, path, &dev->events);
msg = NULL;
state = xenbus_read_integer(path);
while (msg == NULL && state < XenbusStateConnected)
msg = xenbus_wait_for_state_change(path, &state, &dev->events);
if (msg != NULL || state != XenbusStateConnected) {
printk("backend not available, state=%d\n", state);
xenbus_unwatch_path_token(XBT_NIL, path, path);
goto error;
}
}
unmask_evtchn(dev->evtchn);
printk("**************************\n");
return dev;
error:
free(msg);
free(err);
free_consfront(dev);
return NULL;
}
