1 files changed, 155 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/common/up_usestack.c b/nuttx/arch/arm/src/common/up_usestack.c
new file mode 100644
index 000000000..f46be0cc9
--- /dev/null
+++ b/nuttx/arch/arm/src/common/up_usestack.c
@@ -0,0 +1,155 @@
+/****************************************************************************
+ * arch/arm/src/common/up_usestack.c
+ *
+ *   Copyright (C) 2007-2009 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 NuttX 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 <stdint.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/arch.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Macros
+ ****************************************************************************/
+
+/* ARM requires at least a 4-byte stack alignment.  For use with EABI and
+ * floating point, the stack must be aligned to 8-byte addresses.
+ */
+
+#ifndef CONFIG_STACK_ALIGNMENT
+
+/* The symbol  __ARM_EABI__ is defined by GCC if EABI is being used.  If you
+ * are not using GCC, make sure that CONFIG_STACK_ALIGNMENT is set correctly!
+ */
+
+#  ifdef __ARM_EABI__
+#    define CONFIG_STACK_ALIGNMENT 8
+#  else
+#    define CONFIG_STACK_ALIGNMENT 4
+#  endif
+#endif
+
+/* Stack alignment macros */
+
+#define STACK_ALIGN_MASK    (CONFIG_STACK_ALIGNMENT-1)
+#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
+#define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_use_stack
+ *
+ * Description:
+ *   Setup up stack-related information in the TCB
+ *   using pre-allocated stack memory
+ *
+ *   The following TCB fields must be initialized:
+ *   adj_stack_size: Stack size after adjustment for hardware,
+ *     processor, etc.  This value is retained only for debug
+ *     purposes.
+ *   stack_alloc_ptr: Pointer to allocated stack
+ *   adj_stack_ptr: Adjusted stack_alloc_ptr for HW.  The
+ *     initial value of the stack pointer.
+ *
+ * Inputs:
+ *   tcb: The TCB of new task
+ *   stack_size:  The allocated stack size.
+ *
+ ****************************************************************************/
+
+int up_use_stack(_TCB *tcb, void *stack, size_t stack_size)
+{
+  size_t top_of_stack;
+  size_t size_of_stack;
+
+  if (tcb->stack_alloc_ptr)
+    {
+      sched_free(tcb->stack_alloc_ptr);
+    }
+
+  /* Save the stack allocation */
+
+  tcb->stack_alloc_ptr = stack;
+
+  /* The ARM uses a push-down stack:  the stack grows toward lower addresses
+   * in memory.  The stack pointer register, points to the lowest, valid
+   * work address (the "top" of the stack).  Items on the stack are
+   * referenced as positive word offsets from sp.
+   */
+
+  top_of_stack = (uint32_t)tcb->stack_alloc_ptr + stack_size - 4;
+
+  /* The ARM stack must be aligned; 4 byte alignment for OABI and 8-byte
+   * alignment for EABI. If necessary top_of_stack must be rounded down
+   * to the next boundary
+   */
+
+  top_of_stack = STACK_ALIGN_DOWN(top_of_stack);
+
+  /* The size of the stack in bytes is then the difference between
+   * the top and the bottom of the stack (+4 because if the top
+   * is the same as the bottom, then the size is one 32-bit element).
+   * The size need not be aligned.
+   */
+
+  size_of_stack = top_of_stack - (uint32_t)tcb->stack_alloc_ptr + 4;
+
+  /* Save the adjusted stack values in the _TCB */
+
+  tcb->adj_stack_ptr  = (uint32_t*)top_of_stack;
+  tcb->adj_stack_size = size_of_stack;
+
+  return OK;
+}