Basic i.MX1 low-level boot

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1695 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 184 insertions, 0 deletions

diff --git a/nuttx/arch/arm/src/imx/imx_boot.c b/nuttx/arch/arm/src/imx/imx_boot.c
new file mode 100644
index 000000000..88eb341ef
--- /dev/null
+++ b/nuttx/arch/arm/src/imx/imx_boot.c
@@ -0,0 +1,184 @@
+/************************************************************************************
+ * arch/arm/src/imx/imx_boot.c
+ * arch/arm/src/chip/imx_boot.c
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name Gregory Nutt nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ************************************************************************************/
+
+/************************************************************************************
+ * Included Files
+ ************************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+
+#include "up_internal.h"
+#include "up_arch.h"
+
+/************************************************************************************
+ * Private Types
+ ************************************************************************************/
+
+/************************************************************************************
+ * Private Types
+ ************************************************************************************/
+
+struct section_mapping_s
+{
+  uint32 physbase;   /* Physical address of the region to be mapped */
+  uint32 virtbase;   /* Virtual address of the region to be mapped */
+  uint32 mmuflags;   /* MMU settings for the region (e.g., cache-able) */
+  uint32 nsections;  /* Number of mappings in the region */
+};
+
+/************************************************************************************
+ * Public Variables
+ ************************************************************************************/
+
+extern uint32 _vector_start; /* Beginning of vector block */
+extern uint32 _vector_end;   /* End+1 of vector block */
+
+/************************************************************************************
+ * Private Variables
+ ************************************************************************************/
+
+static const struct section_mapping_s section_mapping[] =
+{
+  { IMX_PERIPHERALS_PSECTION, IMX_PERIPHERALS_VSECTION, 
+    IMX_PERIPHERALS_MMUFLAGS, IMX_PERIPHERALS_NSECTIONS},
+  { IMX_FLASH_PSECTION,       IMX_FLASH_VSECTION, 
+    IMX_FLASH_MMUFLAGS,       IMX_FLASH_NSECTIONS},
+};
+
+#define NMAPPINGS (sizeof(section_mapping) / sizeof(struct section_mapping_s))
+
+/************************************************************************************
+ * Private Functions
+ ************************************************************************************/
+
+/************************************************************************************
+ * Name: up_setlevel1entry
+ ************************************************************************************/
+
+static inline void up_setlevel1entry(uint32 paddr, uint32 vaddr, uint32 mmuflags)
+{
+  uint32 *pgtable = (uint32*)PGTABLE_VBASE;
+  uint32  index   = vaddr >> 20;
+
+  /* Save the page table entry */
+
+  pgtable[index]  = (paddr | mmuflags);
+}
+
+/************************************************************************************
+ * Name: up_setupmappings
+ ************************************************************************************/
+
+static void up_setupmappings(void)
+{
+  int i, j;
+
+  for (i = 0; i < NMAPPINGS; i++)
+    {
+      uint32 sect_paddr = section_mapping[i].physbase;
+      uint32 sect_vaddr = section_mapping[i].virtbase;
+      uint32 mmuflags   = section_mapping[i].mmuflags;
+
+      for (j = 0; j < section_mapping[i].nsections; j++)
+        {
+          up_setlevel1entry(sect_paddr, sect_vaddr, mmuflags);
+          sect_paddr += SECTION_SIZE;
+          sect_vaddr += SECTION_SIZE;
+        }
+    }
+}
+
+/************************************************************************************
+ * Name: up_copyvectorblock
+ ************************************************************************************/
+
+static void up_copyvectorblock(void)
+{
+  /* There are three operational memory configurations:
+   *
+   * 1. We execute in place in FLASH (CONFIG_BOOT_RUNFROMFLASH=y).  In this case:
+   *
+   *    - Our vectors must be located at the beginning of FLASH and will
+   *      also be mapped to address zero (because of the i.MX's "double map image."
+   *    - There is nothing to be done here in this case.
+   *
+   * 2. We boot in FLASH but copy ourselves to DRAM from better performance.
+   *    (CONFIG_BOOT_RUNFROMFLASH=n && CONFIG_BOOT_COPYTORAM=y).  In this case:
+   *
+   *    - Our code image is in FLASH and we boot to FLASH initially, then copy
+   *      ourself to DRAM, and
+   *    - DRAM will be mapped to address zero.
+   *    - There is nothing to be done here in this case.
+   *
+   * 3. There is bootloader that copies us to DRAM, but probably not to the beginning
+   *    of DRAM (say to 0x0900:0000) (CONFIG_BOOT_RUNFROMFLASH=n && CONFIG_BOOT_COPYTORAM=n).
+   *    In this case:
+   *
+   *    - DRAM will be mapped to address zero.
+   *    - Interrupt vectors will be copied to address zero in this function.
+   */
+
+#if !defined(CONFIG_BOOT_RUNFROMFLASH) && !defined(CONFIG_BOOT_COPYTORAM)
+  uint32 *src  = (uint32*)&_vector_start;
+  uint32 *end  = (uint32*)&_vector_end;
+  uint32 *dest = (uint32*)VECTOR_BASE;
+
+  while (src < end)
+    {
+      *dest++ = *src++;
+    }
+#endif
+}
+
+/************************************************************************************
+ * Public Functions
+ ************************************************************************************/
+
+void up_boot(void)
+{
+  /* __start provided the basic MMU mappings for SDRAM.  Now provide mappings for all
+   * IO regions (Including the vector region).
+   */
+
+  up_setupmappings();
+
+  /* Setup up vector block.  _vector_start and _vector_end are exported from
+   * up_vector.S
+   */
+
+  up_copyvectorblock();
+}