diff options
Diffstat (limited to 'nuttx/arch/hc/src/m9s12/m9s12_initialstate.c')
-rw-r--r-- | nuttx/arch/hc/src/m9s12/m9s12_initialstate.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/nuttx/arch/hc/src/m9s12/m9s12_initialstate.c b/nuttx/arch/hc/src/m9s12/m9s12_initialstate.c new file mode 100644 index 000000000..7efe77942 --- /dev/null +++ b/nuttx/arch/hc/src/m9s12/m9s12_initialstate.c @@ -0,0 +1,121 @@ +/**************************************************************************** + * 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 +} + |