From a0858f5dc80ec94952af4b32903194c40f61c857 Mon Sep 17 00:00:00 2001
From: patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3>
Date: Mon, 6 Sep 2010 16:21:54 +0000
Subject: Fix clearing of SRAM when clocks reset

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2923 42af7a65-404d-4744-a932-0658087f49c3
---
 nuttx/arch/arm/src/lpc313x/lpc313x_boot.c      | 48 +++++++++++++++++---------
 nuttx/arch/arm/src/lpc313x/lpc313x_lowputc.c   |  6 +---
 nuttx/arch/arm/src/lpc313x/lpc313x_memorymap.h |  2 +-
 3 files changed, 33 insertions(+), 23 deletions(-)

(limited to 'nuttx/arch/arm/src/lpc313x')

diff --git a/nuttx/arch/arm/src/lpc313x/lpc313x_boot.c b/nuttx/arch/arm/src/lpc313x/lpc313x_boot.c
index 8840c6fdb..0a6ad34bf 100755
--- a/nuttx/arch/arm/src/lpc313x/lpc313x_boot.c
+++ b/nuttx/arch/arm/src/lpc313x/lpc313x_boot.c
@@ -285,6 +285,18 @@ static void up_vectormapping(void)
 
 static void up_copyvectorblock(void)
 {
+  uint32_t *src;
+  uint32_t *end;
+  uint32_t *dest;
+
+  /* If we are using vectors in low memory but RAM in that area has been marked
+   * read only, then temparily mark the mapping write-able (non-buffered).
+   */
+
+#if !defined(CONFIG_ARCH_ROMPGTABLE) && defined(CONFIG_ARCH_LOWVECTORS) && defined(CONFIG_PAGING)
+  up_vectorpermissions(MMU_L2_VECTRWFLAGS);
+#endif
+
   /* Copy the vectors into ISRAM at the address that will be mapped to the vector
    * address:
    *
@@ -293,15 +305,21 @@ static void up_copyvectorblock(void)
    *   LPC313X_VECTOR_VADDR - Virtual address of vector table (0x00000000 or 0xffff0000)
    */
 
-  uint32_t *src  = (uint32_t*)&_vector_start;
-  uint32_t *end  = (uint32_t*)&_vector_end;
-  uint32_t *dest = (uint32_t*)LPC313X_VECTOR_VSRAM;
+  src  = (uint32_t*)&_vector_start;
+  end  = (uint32_t*)&_vector_end;
+  dest = (uint32_t*)LPC313X_VECTOR_VSRAM;
 
   while (src < end)
     {
       *dest++ = *src++;
     }
 
+  /* Make the vectors read-only, cacheable again */
+
+#if !defined(CONFIG_ARCH_ROMPGTABLE) && defined(CONFIG_ARCH_LOWVECTORS) && defined(CONFIG_PAGING)
+  up_vectorpermissions(MMU_L2_VECTROFLAGS);
+#endif
+
   /* Then set the LPC313x shadow register, LPC313X_SYSCREG_ARM926SHADOWPTR, so that
    * the vector table is mapped to address 0x0000:0000 - NOTE: that there is not yet
    * full support for the vector table at address 0xffff0000.
@@ -331,14 +349,6 @@ void up_boot(void)
 #ifndef CONFIG_ARCH_ROMPGTABLE
   up_setupmappings();
 
-  /* If we are using vectors in low memory but RAM in that area has been marked
-   * read only, then temparily mark the mapping write-able (non-buffered).
-   */
-
-#if defined(CONFIG_ARCH_LOWVECTORS) && defined(CONFIG_PAGING)
-  up_vectorpermissions(MMU_L2_VECTRWFLAGS);
-#endif
-
   /* Provide a special mapping for the IRAM interrupt vector positioned in high
    * memory.
    */
@@ -354,12 +364,6 @@ void up_boot(void)
 
   up_copyvectorblock();
 
-  /* Make the vectors read-only, cacheable again */
-
-#if !defined(CONFIG_ARCH_ROMPGTABLE) && defined(CONFIG_ARCH_LOWVECTORS) && defined(CONFIG_PAGING)
-  up_vectorpermissions(MMU_L2_VECTROFLAGS);
-#endif
-
   /* Reset all clocks */
 
   lpc313x_resetclks();
@@ -381,6 +385,16 @@ void up_boot(void)
 
   lpc313x_lowsetup();
 
+  /* NOTE:  Something in the operation of lpc313x_resetclks() causes the first
+   * 6 words of memory to be zeroed, wiping out the interrupt vectors.  However,
+   * moving the vector initialization until after the clock setup seems to hang
+   * the system (and I can't step though the clock setup to find why without
+   * losing my JTAG connection).  So, the simplest work-around is to simply
+   * initialize the vectors twice.
+   */
+
+  up_copyvectorblock();
+
   /* Perform early serial initialization if we are going to use the serial driver */
 
 #ifdef CONFIG_USE_EARLYSERIALINIT
diff --git a/nuttx/arch/arm/src/lpc313x/lpc313x_lowputc.c b/nuttx/arch/arm/src/lpc313x/lpc313x_lowputc.c
index 93f9a37b7..5bfde83fc 100755
--- a/nuttx/arch/arm/src/lpc313x/lpc313x_lowputc.c
+++ b/nuttx/arch/arm/src/lpc313x/lpc313x_lowputc.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/arm/src/lpc313x/lpc313x_lowputc.c
  *
- *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2009-2010 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -339,10 +339,6 @@ void lpc313x_lowsetup(void)
 #endif
 }
 
-/****************************************************************************
- * Public Functions
- ****************************************************************************/
-
 /****************************************************************************
  * Name: up_lowputc
  *
diff --git a/nuttx/arch/arm/src/lpc313x/lpc313x_memorymap.h b/nuttx/arch/arm/src/lpc313x/lpc313x_memorymap.h
index ad2281237..0539495f9 100755
--- a/nuttx/arch/arm/src/lpc313x/lpc313x_memorymap.h
+++ b/nuttx/arch/arm/src/lpc313x/lpc313x_memorymap.h
@@ -183,7 +183,7 @@
 
 /* Section MMU Flags */
 
-#define LPC313X_SHADOWSPACE_MMUFLAGS   MMU_MEMFLAGS
+#define LPC313X_SHADOWSPACE_MMUFLAGS   MMU_ROMFLAGS
 #define LPC313X_INTSRAM_MMUFLAGS       MMU_MEMFLAGS
 #define LPC313X_INTSROM_MMUFLAGS       MMU_MEMFLAGS
 #define LPC313X_APB01_MMUFLAGS         MMU_IOFLAGS
-- 
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