NuttX RTOS

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 109 insertions, 0 deletions

diff --git a/nuttx/arch/sim/src/up_createstack.c b/nuttx/arch/sim/src/up_createstack.c
new file mode 100644
index 000000000..0e2c63e4d
--- /dev/null
+++ b/nuttx/arch/sim/src/up_createstack.c
@@ -0,0 +1,109 @@
+/************************************************************
+ * up_createstack.c
+ *
+ *   Copyright (C) 2007 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 <nuttx/arch.h>
+#include <nuttx/kmalloc.h>
+#include "up_internal.h"
+
+/************************************************************
+ * Private Definitions
+ ************************************************************/
+
+/************************************************************
+ * Private Data
+ ************************************************************/
+
+/************************************************************
+ * Private Funtions
+ ************************************************************/
+
+/************************************************************
+ * Public Funtions
+ ************************************************************/
+
+/************************************************************
+ * Name: up_create_stack
+ *
+ * Description:
+ *   Allocate a stack for a new thread and setup
+ *   up stack-related information in the TCB.
+ *
+ *   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 StatckAllocPtr for HW.  The
+ *     initial value of the stack pointer.
+ *
+ * Inputs:
+ *   tcb: The TCB of new task
+ *   stack_size: The requested stack size.  At least this much
+ *     must be allocated.
+ *
+ ************************************************************/
+
+STATUS up_create_stack(_TCB *tcb, uint32 stack_size)
+{
+  STATUS ret = ERROR;
+
+  /* Move up to next even word boundary if necessary */
+
+  uint32 adj_stack_size = (stack_size + 3) & ~3;
+  uint32 adj_stack_words = adj_stack_size >> 2;
+
+  /* Allocate the memory for the stack */
+
+  uint32 *stack_alloc_ptr = (uint32*)kmalloc(adj_stack_size);
+  if (stack_alloc_ptr)
+    {
+      /* This is the address of the last word in the allocation */
+
+      uint32 *adj_stack_ptr = &stack_alloc_ptr[adj_stack_words - 1];
+
+      /* Save the values in the TCB */
+      tcb->adj_stack_size  = adj_stack_size;
+      tcb->stack_alloc_ptr = stack_alloc_ptr;
+      tcb->adj_stack_ptr   = adj_stack_ptr;
+      ret = OK;
+    }
+  return ret;
+}