text: /****************************************************************************
   * arch/z80/src/ez80/ez80_initialstate.c
   *
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.  The
   * ASF licenses this file to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance with the
   * License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
   * License for the specific language governing permissions and limitations
   * under the License.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <stdint.h>
  #include <string.h>
  #include <nuttx/arch.h>
  
  #include "chip.h"
  #include "z80_internal.h"
  #include "z80_arch.h"
  
  /****************************************************************************
   * 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 initial architecture registers
   *   and/or  stack so that execution will begin at tcb->start
   *   on the next context switch.
   *
   ****************************************************************************/
  
  void up_initial_state(FAR struct tcb_s *tcb)
  {
    FAR struct xcptcontext *xcp = &tcb->xcp;
  
    /* Initialize the initial exception register context structure */
  
    memset(xcp, 0, sizeof(struct xcptcontext));
  
  #ifndef CONFIG_SUPPRESS_INTERRUPTS
    /* Parity/Overflow flag will enable interrupts */
  
    ((FAR uint8_t *)xcp->regs)[XCPT_IF_OFFSET] = EZ80_PV_FLAG;
  #endif
  
    xcp->regs[XCPT_SP] = (chipreg_t)tcb->stack_base_ptr +
                                    tcb->adj_stack_size;
    xcp->regs[XCPT_PC] = (chipreg_t)tcb->start;
  }
  