Added UNDI root bus driver (which saves including all the PCI bus code,

UNDI ROM code etc. when you just want a "undi.kpxe"-type image).

This driver cannot be used in conjunction with any other driver (it will
crash), or in any other format than .kpxe (it just won't find any network
devices).

src/arch/i386/drivers/net/undionly.c

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <gpxe/device.h>
+#include <undi.h>
+#include <undinet.h>
+#include <undipreload.h>
+
+/** @file
+ *
+ * "Pure" UNDI driver
+ *
+ * This is the UNDI driver without explicit support for PCI or any
+ * other bus type.  It is capable only of using the preloaded UNDI
+ * device.  It must not be combined in an image with any other
+ * drivers.
+ *
+ * If you want a PXE-loadable image that contains only the UNDI
+ * driver, build "bin/undionly.kpxe".
+ *
+ * If you want any other image format, or any other drivers in
+ * addition to the UNDI driver, build e.g. "bin/undi.dsk".
+ */
+
+/**
+ * Probe UNDI root bus
+ *
+ * @v rootdev		UNDI bus root device
+ *
+ * Scans the UNDI bus for devices and registers all devices it can
+ * find.
+ */
+static int undibus_probe ( struct root_device *rootdev ) {
+	int rc;
+
+	/* Check for a valie preloaded UNDI device */
+	if ( ! preloaded_undi.entry.segment ) {
+		DBG ( "No preloaded UNDI device found!\n" );
+		return -ENODEV;
+	}
+
+	/* Add to device hierarchy */
+	preloaded_undi.dev.parent = &rootdev->dev;
+	list_add ( &preloaded_undi.dev.siblings, &rootdev->dev.children);
+	INIT_LIST_HEAD ( &preloaded_undi.dev.children );
+
+	/* Create network device */
+	if ( ( rc = undinet_probe ( &preloaded_undi ) ) != 0 )
+		goto err;
+
+	return 0;
+
+ err:
+	list_del ( &preloaded_undi.dev.siblings );
+	return rc;
+}
+
+/**
+ * Remove UNDI root bus
+ *
+ * @v rootdev		UNDI bus root device
+ */
+static void undibus_remove ( struct root_device *rootdev __unused ) {
+	undinet_remove ( &preloaded_undi );
+	list_del ( &preloaded_undi.dev.siblings );
+}
+
+/** UNDI bus root device driver */
+static struct root_driver undi_root_driver = {
+	.probe = undibus_probe,
+	.remove = undibus_remove,
+};
+
+/** UNDI bus root device */
+struct root_device undi_root_device __root_device = {
+	.name = "UNDI",
+	.driver = &undi_root_driver,
+};