nios2: Add Altera 10M50 GHRD emulation

Add the Altera 10M50 Nios2 GHRD model. This allows emulating the
10M50 development kit with the Nios2 GHRD loaded in the FPGA. It
is possible to boot Linux kernel and run userspace, thus far only
from initrd as storage support is not yet implemented.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chris Wulff <crwulff@gmail.com>
Cc: Jeff Da Silva <jdasilva@altera.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Sandra Loosemore <sandra@codesourcery.com>
Cc: Yves Vandervennet <yvanderv@altera.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Message-Id: <20170118220146.489-7-marex@denx.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>

1 files changed, 70 insertions, 0 deletions

diff --git a/hw/nios2/cpu_pic.c b/hw/nios2/cpu_pic.c
new file mode 100644
index 0000000..0f95987
--- /dev/null
+++ b/hw/nios2/cpu_pic.c
@@ -0,0 +1,70 @@
+/*
+ * Altera Nios2 CPU PIC
+ *
+ * Copyright (c) 2016 Marek Vasut <marek.vasut@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu-common.h"
+#include "cpu.h"
+
+#include "qemu/config-file.h"
+
+#include "boot.h"
+
+static void nios2_pic_cpu_handler(void *opaque, int irq, int level)
+{
+    Nios2CPU *cpu = opaque;
+    CPUNios2State *env = &cpu->env;
+    CPUState *cs = CPU(cpu);
+    int type = irq ? CPU_INTERRUPT_NMI : CPU_INTERRUPT_HARD;
+
+    if (type == CPU_INTERRUPT_HARD) {
+        env->irq_pending = level;
+
+        if (level && (env->regs[CR_STATUS] & CR_STATUS_PIE)) {
+            env->irq_pending = 0;
+            cpu_interrupt(cs, type);
+        } else if (!level) {
+            env->irq_pending = 0;
+            cpu_reset_interrupt(cs, type);
+        }
+    } else {
+        if (level) {
+            cpu_interrupt(cs, type);
+        } else {
+            cpu_reset_interrupt(cs, type);
+        }
+    }
+}
+
+void nios2_check_interrupts(CPUNios2State *env)
+{
+    Nios2CPU *cpu = nios2_env_get_cpu(env);
+    CPUState *cs = CPU(cpu);
+
+    if (env->irq_pending) {
+        env->irq_pending = 0;
+        cpu_interrupt(cs, CPU_INTERRUPT_HARD);
+    }
+}
+
+qemu_irq *nios2_cpu_pic_init(Nios2CPU *cpu)
+{
+    return qemu_allocate_irqs(nios2_pic_cpu_handler, cpu, 2);
+}