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+/****************************************************************************
+ * arch/hc/src/m9s12/m9s12_initialstate.c
+ *
+ * Copyright (C) 2011 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 <string.h>
+
+#include <nuttx/sched.h>
+#include <arch/irq.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_initial_state
+ *
+ * Description:
+ * A new thread is being started and a new TCB
+ * has been created. This function is called to initialize
+ * the processor specific portions of the new TCB.
+ *
+ * This function must setup the intial architecture registers
+ * and/or stack so that execution will begin at tcb->start
+ * on the next context switch.
+ *
+ ****************************************************************************/
+
+void up_initial_state(_TCB *tcb)
+{
+ struct xcptcontext *xcp = &tcb->xcp;
+
+ /* Initialize the initial exception register context structure */
+
+ memset(xcp, 0, sizeof(struct xcptcontext));
+
+ /* Save the initial stack pointer */
+
+ xcp->regs[REG_SPH] = (uint16_t)tcb->adj_stack_ptr >> 8;
+ xcp->regs[REG_SPL] = (uint16_t)tcb->adj_stack_ptr & 0xff;
+
+ /* Save the task entry point */
+
+ xcp->regs[REG_PCH] = (uint16_t)tcb->start >> 8;
+ xcp->regs[REG_PCL] = (uint16_t)tcb->start & 0xff;
+
+#ifndef CONFIG_HCS12_NONBANKED
+ /* Can only directly start in PPAGE 0x30 */
+
+ xcp->regs[REG_PPAGE] = 0x30;
+#endif
+
+ /* Condition code register:
+ *
+ * Bit 0: C — Carry/Borrow status bit
+ * Bit 1: V — Two’s complement overflow status bit
+ * Bit 2: Z — Zero status bit
+ * Bit 3: N — Negative status bit
+ * Bit 4: I — Maskable interrupt control bit
+ * Bit 5: H — Half-carry status bit
+ * Bit 6: X — Non-maskable interrupt control bit
+ * Bit 7: S — STOP instruction control bit
+ */
+
+# ifdef CONFIG_SUPPRESS_INTERRUPTS
+ xcp->regs[REG_CCR] = 0xd0; /* Disable STOP, Mask I- and Z- interrupts */
+# else
+ xcp->regs[REG_CCR] = 0x80; /* Disable STOP, Enable I- and Z-interrupts */
+# endif
+}
+