riscv-spike: support for Spike emulation of riscv

Spike support: QEMU RISCV is broken, and the maintainers at Berkeley
are working on it, but at the moment spike is the only way to  test
on riscv. Add support for spike console output for debugging.

Privileged ISA: Update to privileged ISA in RISCV (machine,
supervisor, hypervisor, user modes) broke exisitng RISCV asm, and
bootblock.S was updated to match the new spec. Clean old assembly

[pg: things build with gcc 4.9 now, but don't expect them to work.
Hardcoding register names into the assembler language may not be the smartest
idea of the RISCV folks.]

Change-Id: Ie2c109d3c26712c207512f74f28ce1a925e6e181
Signed-off-by: Thaminda Edirisooriya <thaminda@google.com>
Reviewed-on: http://review.coreboot.org/11078
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 61 insertions, 0 deletions

diff --git a/src/mainboard/emulation/spike-riscv/uart.c b/src/mainboard/emulation/spike-riscv/uart.c
new file mode 100644
index 0000000000..961ddc56d4
--- /dev/null
+++ b/src/mainboard/emulation/spike-riscv/uart.c
@@ -0,0 +1,61 @@
+/*
+ * 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.
+ */
+
+#include <types.h>
+#include <console/uart.h>
+#include <arch/io.h>
+#include <boot/coreboot_tables.h>
+#include <spike_util.h>
+
+static uint8_t *buf = (void *)0x3f8;
+uintptr_t uart_platform_base(int idx)
+{
+	return (uintptr_t) buf;
+}
+
+void uart_init(int idx)
+{
+}
+
+unsigned char uart_rx_byte(int idx)
+{
+	return *buf; // this does not work on spike, requires more implementation details
+}
+
+void uart_tx_byte(int idx, unsigned char data)
+{
+	mcall_console_putchar(data);
+}
+
+void uart_tx_flush(int idx)
+{
+}
+
+#ifndef __PRE_RAM__
+void uart_fill_lb(void *data)
+{
+	struct lb_serial serial;
+	serial.type = LB_SERIAL_TYPE_MEMORY_MAPPED;
+	serial.baseaddr = 0x3f8;
+	serial.baud = 115200;
+	serial.regwidth = 1;
+	lb_add_serial(&serial, data);
+        lb_add_console(LB_TAG_CONSOLE_SERIAL8250MEM, data);
+}
+#endif