[ 32.314] (==) No screen section available. Using defaults.
[ 32.314] (**) |-->Screen "Default Screen Section" (0)
[ 32.314] (**) | |-->Monitor "<default monitor>"
[ 32.315] (==) No monitor specified for screen "Default Screen Section".
Using a default monitor configuration.
static Bool
configScreen(confScreenPtr screenp, XF86ConfScreenPtr conf_screen, int scrnum,
MessageType from)
{
int count = 0;
XF86ConfDisplayPtr dispptr;
XF86ConfAdaptorLinkPtr conf_adaptor;
Bool defaultMonitor = FALSE;
XF86ConfScreenRec local_conf_screen;
if (!conf_screen) {
memset(&local_conf_screen, 0, sizeof(local_conf_screen));
conf_screen = &local_conf_screen;
conf_screen->scrn_identifier = "Default Screen Section";
xf86Msg(X_DEFAULT, "No screen section available. Using defaults.\n");
}
xf86Msg(from, "|-->Screen \"%s\" (%d)\n", conf_screen->scrn_identifier,
scrnum);
/*
* now we fill in the elements of the screen
*/
screenp->id = conf_screen->scrn_identifier;
screenp->screennum = scrnum;
screenp->defaultdepth = conf_screen->scrn_defaultdepth;
screenp->defaultbpp = conf_screen->scrn_defaultbpp;
screenp->defaultfbbpp = conf_screen->scrn_defaultfbbpp;
screenp->monitor = xnfcalloc(1, sizeof(MonRec));
/* If no monitor is specified, create a default one. */
if (!conf_screen->scrn_monitor) {
XF86ConfMonitorRec defMon;
memset(&defMon, 0, sizeof(defMon));
defMon.mon_identifier = "<default monitor>";
if (!configMonitor(screenp->monitor, &defMon))
return FALSE;
defaultMonitor = TRUE;
}
else {
if (!configMonitor(screenp->monitor, conf_screen->scrn_monitor))
return FALSE;
}
/* Configure the device. If there isn‘t one configured, attach to the
* first inactive one that we can configure. If there‘s none that work,
* set it to NULL so that the section can be autoconfigured later */
screenp->device = xnfcalloc(1, sizeof(GDevRec));
if ((!conf_screen->scrn_device) && (xf86configptr->conf_device_lst)) {
conf_screen->scrn_device = xf86configptr->conf_device_lst;
xf86Msg(X_DEFAULT, "No device specified for screen \"%s\".\n"
"\tUsing the first device section listed.\n", screenp->id);
}
if (configDevice(screenp->device, conf_screen->scrn_device, TRUE)) {
screenp->device->myScreenSection = screenp;
}
else {
screenp->device = NULL;
}
screenp->options = conf_screen->scrn_option_lst;
/*
* figure out how many display subsections there are and fill them in
*/
dispptr = conf_screen->scrn_display_lst;
while (dispptr) {
count++;
dispptr = (XF86ConfDisplayPtr) dispptr->list.next;
}
screenp->displays = xnfalloc((count) * sizeof(DispRec));
screenp->numdisplays = count;
/* Fill in the default Virtual size, if any */
if (conf_screen->scrn_virtualX && conf_screen->scrn_virtualY) {
for (count = 0, dispptr = conf_screen->scrn_display_lst;
dispptr;
dispptr = (XF86ConfDisplayPtr) dispptr->list.next, count++) {
screenp->displays[count].virtualX = conf_screen->scrn_virtualX;
screenp->displays[count].virtualY = conf_screen->scrn_virtualY;
}
}
/* Now do the per-Display Virtual sizes */
count = 0;
dispptr = conf_screen->scrn_display_lst;
while (dispptr) {
configDisplay(&(screenp->displays[count]), dispptr);
count++;
dispptr = (XF86ConfDisplayPtr) dispptr->list.next;
}
/*
* figure out how many videoadaptor references there are and fill them in
*/
conf_adaptor = conf_screen->scrn_adaptor_lst;
while (conf_adaptor) {
count++;
conf_adaptor = (XF86ConfAdaptorLinkPtr) conf_adaptor->list.next;
}
screenp->xvadaptors = xnfalloc((count) * sizeof(confXvAdaptorRec));
screenp->numxvadaptors = 0;
conf_adaptor = conf_screen->scrn_adaptor_lst;
while (conf_adaptor) {
if (configXvAdaptor(&(screenp->xvadaptors[screenp->numxvadaptors]),
conf_adaptor->al_adaptor))
screenp->numxvadaptors++;
conf_adaptor = (XF86ConfAdaptorLinkPtr) conf_adaptor->list.next;
}
if (defaultMonitor) {
xf86Msg(X_DEFAULT, "No monitor specified for screen \"%s\".\n"
"\tUsing a default monitor configuration.\n", screenp->id);
}
return TRUE;
}xorg初始化过程，没有配置文件，用默认值
原文：http://blog.csdn.net/oldlinux/article/details/43820455
