126 lines
4.5 KiB
C
126 lines
4.5 KiB
C
/****************************************************************************
|
||
* arch/hc/src/m9s12/m9s12_initialstate.c
|
||
*
|
||
* Copyright (C) 2011 Gregory Nutt. All rights reserved.
|
||
* Author: Gregory Nutt <gnutt@nuttx.org>
|
||
*
|
||
* 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(struct tcb_s *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 <20> Carry/Borrow status bit
|
||
* Bit 1: V <20> Two<77>s complement overflow status bit
|
||
* Bit 2: Z <20> Zero status bit
|
||
* Bit 3: N <20> Negative status bit
|
||
* Bit 4: I <20> Maskable interrupt control bit
|
||
* Bit 5: H <20> Half-carry status bit
|
||
* Bit 6: X <20> Non-maskable interrupt control bit
|
||
* Bit 7: S <20> STOP instruction control bit
|
||
*/
|
||
|
||
# ifdef CONFIG_SUPPRESS_INTERRUPTS
|
||
/* Disable STOP, Mask I- and Z- interrupts */
|
||
|
||
xcp->regs[REG_CCR] = HCS12_CCR_S|HCS12_CCR_X|HCS12_CCR_I;
|
||
# else
|
||
/* Disable STOP, Enable I- and Z-interrupts */
|
||
|
||
xcp->regs[REG_CCR] = HCS12_CCR_S;
|
||
# endif
|
||
}
|
||
|