text: /*
   * Copyright (c) 2013-2014 Wind River Systems, Inc.
   *
   * Licensed 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.
   */
  
  /**
   * @file
   * @brief Full C support initialization
   *
   *
   * Initialization of full C support: zero the .bss, copy the .data if XIP,
   * call _Cstart().
   *
   * Stack is available in this module, but not the global data/bss until their
   * initialization is performed.
   */
  
  #include <kernel.h>
  #include <stdint.h>
  #include <toolchain.h>
  #include <linker-defs.h>
  #include <nano_internal.h>
  
  #ifdef CONFIG_XIP
  static inline void relocate_vector_table(void) { /* do nothing */ }
  #else
  static inline void relocate_vector_table(void)
  {
  	/* vector table is already in SRAM, just point to it */
  	_scs_relocate_vector_table((void *)CONFIG_SRAM_BASE_ADDRESS);
  }
  #endif
  
  #ifdef CONFIG_FLOAT
  static inline void enable_floating_point(void)
  {
  	/*
  	 * Upon reset, the Co-Processor Access Control Register is 0x00000000.
  	 * Enable CP10 and CP11 coprocessors to enable floating point.
  	 */
  	__scs.cpacr.val = (_SCS_CPACR_CP10_FULL_ACCESS |
  				_SCS_CPACR_CP11_FULL_ACCESS);
  
  	/*
  	 * Upon reset, the FPU Context Control Register is 0xC0000000
  	 * (both Automatic and Lazy state preservation is enabled).
  	 * Disable lazy state preservation so the volatile FP registers are
  	 * always saved on exception.
  	 */
  	__scs.fpu.ccr.val = (_SCS_FPU_CCR_ASPEN_ENABLE |
  				_SCS_FPU_CCR_LSPEN_DISABLE);
  
  	/*
  	 * Although automatic state preservation is enabled, the processor
  	 * does not automatically save the volatile FP registers until they
  	 * have first been touched. Perform a dummy move operation so that
  	 * the stack frames are created as expected before any task or fiber
  	 * context switching can occur.
  	 */
  	__asm__ volatile(
  		"vmov s0, s0;\n\t"
  		"dsb;\n\t"
  		"isb;\n\t"
  		);
  }
  #else
  static inline void enable_floating_point(void)
  {
  }
  #endif
  
  extern FUNC_NORETURN void _Cstart(void);
  /**
   *
   * @brief Prepare to and run C code
   *
   * This routine prepares for the execution of and runs C code.
   *
   * @return N/A
   */
  
  void _PrepC(void)
  {
  	relocate_vector_table();
  	enable_floating_point();
  	_bss_zero();
  	_data_copy();
  	_Cstart();
  	CODE_UNREACHABLE;
  }
  