2011-10-21 Sebastian Huber <sebastian.huber@embedded-brains.de>

	* nios2-mpu-configuration.c, nios2-mpu-descriptor.c,
	nios2-mpu-disable-protected.c, nios2-mpu-reset.c: New files.
	* Makefile.am: Reflect changes above.
	* rtems/score/nios2-utility.h, nios2-context-initialize.c: Added
	support for the memory protection unit (MPU).

1 files changed, 121 insertions, 0 deletions

diff --git a/cpukit/score/cpu/nios2/nios2-mpu-descriptor.c b/cpukit/score/cpu/nios2/nios2-mpu-descriptor.c
new file mode 100644
index 0000000000..2b3cc41564
--- /dev/null
+++ b/cpukit/score/cpu/nios2/nios2-mpu-descriptor.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2011 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Obere Lagerstr. 30
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ *
+ * $Id$
+ */
+
+#ifdef HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/score/nios2-utility.h>
+
+static bool _Nios2_Is_power_of_two( uint32_t size )
+{
+  bool ok = false;
+  int i = 0;
+
+  for ( i = 0; !ok && i < 32; ++i ) {
+    ok = size == (1U << i);
+  }
+
+  return ok;
+}
+
+static bool _Nios2_Is_valid_base_and_end(
+  const Nios2_MPU_Configuration *config,
+  bool data,
+  uint32_t base,
+  uint32_t end,
+  uint32_t *mask_or_limit
+)
+{
+  uint32_t size = end - base;
+  uint32_t end_limit = data ?
+    (1U << config->data_address_width)
+      : (1U << config->instruction_address_width);
+  uint32_t mask = data ?
+    ((1U << config->data_region_size_log2)) - 1
+      : ((1U << config->instruction_region_size_log2)) - 1;
+  bool ok = base < end && end <= end_limit
+    && (base & mask) == 0 && (end & mask) == 0;
+
+  if ( config->region_uses_limit ) {
+    *mask_or_limit = end;
+  } else {
+    ok = ok && _Nios2_Is_power_of_two( size );
+    *mask_or_limit = (~(size - 1)) & NIOS2_MPUACC_MASK_MASK;
+  }
+
+  return ok;
+}
+
+static bool _Nios2_Is_valid_index(
+  const Nios2_MPU_Configuration *config,
+  bool data,
+  int index
+)
+{
+  int count = data ?
+    config->data_region_count
+      : config->instruction_region_count;
+
+  return 0 <= index && index < count;
+}
+
+static bool _Nios2_Is_valid_permission(
+  bool data,
+  int perm
+)
+{
+  int max = data ? 6 : 2;
+
+  return 0 <= perm && perm <= max && (!data || (data && perm != 3));
+}
+
+bool _Nios2_MPU_Setup_region_registers(
+  const Nios2_MPU_Configuration *config,
+  const Nios2_MPU_Region_descriptor *desc,
+  uint32_t *mpubase,
+  uint32_t *mpuacc
+)
+{
+  uint32_t base = (uint32_t) desc->base;
+  uint32_t end = (uint32_t) desc->end;
+  uint32_t mask_or_limit = 0;
+  bool is_valid_base_and_end = _Nios2_Is_valid_base_and_end(
+    config,
+    desc->data,
+    base,
+    end,
+    &mask_or_limit
+  );
+  bool ok = is_valid_base_and_end
+    && _Nios2_Is_valid_index( config, desc->data, desc->index )
+    && _Nios2_Is_valid_permission( desc->data, desc->perm )
+    && !(!desc->data && desc->cacheable)
+    && !(desc->read && desc->write);
+
+  if ( ok ) {
+    *mpubase = (base & NIOS2_MPUBASE_BASE_MASK)
+      | ((desc->index << NIOS2_MPUBASE_INDEX_OFFSET) & NIOS2_MPUBASE_INDEX_MASK)
+      | (desc->data ? NIOS2_MPUBASE_D : 0);
+    *mpuacc = mask_or_limit
+      | (desc->cacheable ? NIOS2_MPUACC_C : 0)
+      | ((desc->perm << NIOS2_MPUACC_PERM_OFFSET) & NIOS2_MPUACC_PERM_MASK)
+      | (desc->read ? NIOS2_MPUACC_RD : 0)
+      | (desc->write ? NIOS2_MPUACC_WR : 0);
+  }
+
+  return ok;
+}