[PATCH 2/5] bsp/lpc32xx: Restore lpc32xx_set_translation_table_entries()

[Sebastian Huber]

This implementation disables the MMU during the modification of the
translation table.  This behaviour is required by boot loaders for these
boards.
---
 bsps/arm/lpc32xx/include/bsp/mmu.h  |  7 +--
 bsps/arm/lpc32xx/start/mmu.c        | 81 +++++++++++++++++++++++++++++
 spec/build/bsps/arm/lpc32xx/obj.yml |  1 +
 3 files changed, 84 insertions(+), 5 deletions(-)
 create mode 100644 bsps/arm/lpc32xx/start/mmu.c

diff --git a/bsps/arm/lpc32xx/include/bsp/mmu.h b/bsps/arm/lpc32xx/include/bsp/mmu.h
index 58109ac8f6..ba628a19f0 100644
--- a/bsps/arm/lpc32xx/include/bsp/mmu.h
+++ b/bsps/arm/lpc32xx/include/bsp/mmu.h
@@ -74,14 +74,11 @@ extern "C" {
  *
  * @return Previous section flags of the first modified entry.
  */
-static inline uint32_t lpc32xx_set_translation_table_entries(
+uint32_t lpc32xx_set_translation_table_entries(
   const void *begin,
   const void *end,
   uint32_t section_flags
-)
-{
-  return arm_cp15_set_translation_table_entries(begin, end, section_flags);
-}
+);
 
 /** @} */
 
diff --git a/bsps/arm/lpc32xx/start/mmu.c b/bsps/arm/lpc32xx/start/mmu.c
new file mode 100644
index 0000000000..0c2f355a45
--- /dev/null
+++ b/bsps/arm/lpc32xx/start/mmu.c
@@ -0,0 +1,81 @@
+/**
+ * @file
+ *
+ * @ingroup lpc32xx_mmu
+ *
+ * @brief MMU support implementation.
+ */
+
+/*
+ * Copyright (c) 2010-2011 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Obere Lagerstr. 30
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems at 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.
+ */
+
+#include <bsp/mmu.h>
+
+static uint32_t disable_mmu(void)
+{
+  uint32_t ctrl = 0;
+
+  arm_cp15_data_cache_test_and_clean_and_invalidate();
+
+  ctrl = arm_cp15_get_control();
+  arm_cp15_set_control(ctrl & ~ARM_CP15_CTRL_M);
+
+  arm_cp15_tlb_invalidate();
+
+  return ctrl;
+}
+
+static void restore_mmu_control(uint32_t ctrl)
+{
+  arm_cp15_set_control(ctrl);
+}
+
+static uint32_t set_translation_table_entries(
+  const void *begin,
+  const void *end,
+  uint32_t section_flags
+)
+{
+  uint32_t *ttb = arm_cp15_get_translation_table_base();
+  uint32_t i = ARM_MMU_SECT_GET_INDEX(begin);
+  uint32_t iend = ARM_MMU_SECT_GET_INDEX(ARM_MMU_SECT_MVA_ALIGN_UP(end));
+  uint32_t ctrl = disable_mmu();
+  uint32_t section_flags_of_first_entry = ttb [i];
+
+  while (i < iend) {
+    ttb [i] = (i << ARM_MMU_SECT_BASE_SHIFT) | section_flags;
+    ++i;
+  }
+
+  restore_mmu_control(ctrl);
+
+  return section_flags_of_first_entry;
+}
+
+uint32_t lpc32xx_set_translation_table_entries(
+  const void *begin,
+  const void *end,
+  uint32_t section_flags
+)
+{
+  rtems_interrupt_level level;
+  uint32_t section_flags_of_first_entry = 0;
+
+  rtems_interrupt_disable(level);
+  section_flags_of_first_entry =
+    set_translation_table_entries(begin, end, section_flags);
+  rtems_interrupt_enable(level);
+
+  return section_flags_of_first_entry;
+}
diff --git a/spec/build/bsps/arm/lpc32xx/obj.yml b/spec/build/bsps/arm/lpc32xx/obj.yml
index d039fdd0be..86dfda869a 100644
--- a/spec/build/bsps/arm/lpc32xx/obj.yml
+++ b/spec/build/bsps/arm/lpc32xx/obj.yml
@@ -48,6 +48,7 @@ source:
 - bsps/arm/lpc32xx/start/bspstart.c
 - bsps/arm/lpc32xx/start/bspstarthooks.c
 - bsps/arm/lpc32xx/start/emc.c
+- bsps/arm/lpc32xx/start/mmu.c
 - bsps/arm/lpc32xx/start/restart.c
 - bsps/arm/lpc32xx/start/system-clocks.c
 - bsps/arm/lpc32xx/start/timer.c
-- 
2.35.3