Add UCB RISCV support for architecture, soc, and emulation mainboard..

Works in the RISCV version of QEMU.

Note that the lzmadecode is so unclean that it needs a lot of work.
A cleanup is in progress.

We decided in Prague to do this as one thing, because it forms a nice case study
of the bare minimum you need to add to get a new architecture going in qemu.

Change-Id: If5af15c3a70733d219973e0d032746f8ab027e4d
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: http://review.coreboot.org/7584
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins)

1 files changed, 52 insertions, 0 deletions

diff --git a/src/arch/riscv/stages.c b/src/arch/riscv/stages.c
new file mode 100644
index 0000000000..570ba9ebc4
--- /dev/null
+++ b/src/arch/riscv/stages.c
@@ -0,0 +1,52 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 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
+ */
+
+/*
+ * This file contains entry/exit functions for each stage during coreboot
+ * execution (bootblock entry and ramstage exit will depend on external
+ * loading).
+ *
+ * Entry points must be placed at the location the previous stage jumps
+ * to (the lowest address in the stage image). This is done by giving
+ * stage_entry() its own section in .text and placing it first in the
+ * linker script.
+ */
+
+#include <arch/stages.h>
+
+void stage_entry(void)
+{
+	main();
+}
+
+/* we had marked 'doit' as 'noreturn'.
+ * There is no apparent harm in leaving it as something we can return from, and in the one
+ * case where we call a payload, the payload is allowed to return.
+ * Hence, leave it as something we can return from.
+ */
+void stage_exit(void *addr)
+{
+	void (*doit)(void) = addr;
+	/*
+	 * Most stages load code so we need to sync caches here. Should maybe
+	 * go into cbfs_load_stage() instead...
+	 */
+	//cache_sync_instructions();
+	doit();
+}