Strip down i386 PCI configuration space I/O to the bare minimum. A

typical build will now include 880 bytes of PCI support code, compared to
2327 bytes in Etherboot 5.4.

(There is a slight cost of around 5 extra bytes per access to a
non-constant config space address; this should be an overall win.
Driver-specific accesses will usually be to constant addresses, for
which there is no additional cost.)

src/arch/i386/core/pcidirect.c

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2006 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 <gpxe/pci.h>
+#include <pcidirect.h>
+
+/** @file
+ *
+ * PCI configuration space access via Type 1 accesses
+ *
+ */
+
+/**
+ * Prepare for Type 1 PCI configuration space access
+ *
+ * @v pci		PCI device
+ * @v where	Location within PCI configuration space
+ */
+void pcidirect_prepare ( struct pci_device *pci, int where ) {
+	outl ( ( 0x80000000 | ( pci->bus << 16 ) | ( pci->devfn << 8 ) |
+		 ( where & ~3 ) ), PCIDIRECT_CONFIG_ADDRESS );
+}
+