soc/intel/skylake: Use Broadwell as comparision base for Skylake SOC

Use the Broadwell implementation as the comparison base for Skylake.

BRANCH=none
BUG=None
TEST=None

Change-Id: I22eb55ea89eb0d6883f98e4c72a6d243e819e6d8
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: http://review.coreboot.org/10340
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/src/soc/intel/skylake/bootblock/systemagent.c b/src/soc/intel/skylake/bootblock/systemagent.c
new file mode 100644
index 0000000000..15e7fc88b4
--- /dev/null
+++ b/src/soc/intel/skylake/bootblock/systemagent.c
@@ -0,0 +1,44 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 Google Inc.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <arch/io.h>
+#include <soc/pci_devs.h>
+#include <soc/systemagent.h>
+
+static void bootblock_northbridge_init(void)
+{
+	uint32_t reg;
+
+	/*
+	 * The "io" variant of the config access is explicitly used to
+	 * setup the PCIEXBAR because CONFIG_MMCONF_SUPPORT_DEFAULT is set to
+	 * to true. That way all subsequent non-explicit config accesses use
+	 * MCFG. This code also assumes that bootblock_northbridge_init() is
+	 * the first thing called in the non-asm boot block code. The final
+	 * assumption is that no assembly code is using the
+	 * CONFIG_MMCONF_SUPPORT_DEFAULT option to do PCI config accesses.
+	 *
+	 * The PCIEXBAR is assumed to live in the memory mapped IO space under
+	 * 4GiB.
+	 */
+	reg = 0;
+	pci_io_write_config32(SA_DEV_ROOT, PCIEXBAR + 4, reg);
+	reg = CONFIG_MMCONF_BASE_ADDRESS | 4 | 1; /* 64MiB - 0-63 buses. */
+	pci_io_write_config32(SA_DEV_ROOT, PCIEXBAR, reg);
+}