pinebuds/platform/cmsis/retarget_gcc.cpp

/***************************************************************************
 *
 * Copyright 2015-2019 BES.
 * All rights reserved. All unpublished rights reserved.
 *
 * No part of this work may be used or reproduced in any form or by any
 * means, or stored in a database or retrieval system, without prior written
 * permission of BES.
 *
 * Use of this work is governed by a license granted by BES.
 * This work contains confidential and proprietary information of
 * BES. which is protected by copyright, trade secret,
 * trademark and other intellectual property rights.
 *
 ****************************************************************************/
#if (defined(__GNUC__) && !defined(__ARMCC_VERSION))

#if !defined(NOSTD) && !defined(MBED)
#define LIBC_HOOKS
#endif

#ifdef LIBC_HOOKS

#include "hal_trace.h"
#include <errno.h>

#ifndef FILEHANDLE
typedef int FILEHANDLE;
#endif

#define WEAK __attribute__((weak))
#define PACKED __attribute__((packed))

#include <sys/stat.h>
#include <sys/syslimits.h>
#include <sys/unistd.h>
#define PREFIX(x) x

extern "C" int PREFIX(_write)(FILEHANDLE fh, const unsigned char *buffer,
                              unsigned int length, int mode) {
  int n = 0; // n is the number of bytes written
  if (fh < 3) {
    hal_trace_output(buffer, length);
    n = length;
  }
  return n;
}

extern "C" int PREFIX(_read)(FILEHANDLE fh, unsigned char *buffer,
                             unsigned int length, int mode) {
  int n = 0; // n is the number of bytes read
  if (fh < 3) {
    // only read a character at a time from stdin
    // TODO: Read from trace uart input
    n = 1;
  }
  return n;
}

#if defined(__GNUC__)
/* prevents the exception handling name demangling code getting pulled in */
namespace __gnu_cxx {
void __verbose_terminate_handler() { ASSERT(0, "Exception"); }
}
extern "C" WEAK void __cxa_pure_virtual(void);
extern "C" WEAK void __cxa_pure_virtual(void) { _exit(1); }

#endif

// Provide implementation of _sbrk (low-level dynamic memory allocation
// routine) for GCC_ARM which compares new heap pointer with MSP instead of
// SP.  This make it compatible with RTX RTOS thread stacks.
#if defined(__GNUC__) && defined(__arm__)
// Linker defined symbol used by _sbrk to indicate where heap should start.
extern "C" int __end__;
extern "C" uint32_t __HeapLimit;

// Turn off the errno macro and use actual global variable instead.
#undef errno
extern "C" int errno;

// For ARM7 only
register unsigned char *stack_ptr __asm("sp");

// Dynamic memory allocation related syscall.
extern "C" caddr_t _sbrk(int incr) {
  static unsigned char *heap = (unsigned char *)&__end__;
  unsigned char *prev_heap = heap;
  unsigned char *new_heap = heap + incr;

#if defined(TARGET_ARM7)
  if (new_heap >= stack_ptr) {
#elif defined(TARGET_CORTEX_A)
  if (new_heap >=
      (unsigned char *)&__HeapLimit) { /* __HeapLimit is end of heap section */
#else
  if (new_heap >=
      (unsigned char *)&__HeapLimit) { /* __HeapLimit is end of heap section */
#endif
    ASSERT(false, "_sbrk:Heap overflowed: start=%p end=%p cur=%p incr=%d",
           (unsigned char *)&__end__, (unsigned char *)&__HeapLimit, heap,
           incr);
    errno = ENOMEM;
    return (caddr_t)-1;
  }

  TRACE(2, "_sbrk: incr %d cur=%p\n", incr, heap);

  heap = new_heap;
  return (caddr_t)prev_heap;
}
#endif

#if defined(__GNUC__) && defined(__arm__)
extern "C" void _exit(int return_code) {
#else
namespace std {
extern "C" void exit(int return_code) {
#endif
  if (return_code) {
    ASSERT(false, "system die: %d", return_code);
  }

  do {
    volatile int i = 0;
    i++;
  } while (1);
}

#if !(defined(__GNUC__) && defined(__arm__)) && !defined(TOOLCHAIN_GCC_CW)
} // namespace std
#endif

#endif /*LIBC_HOOKS*/

#endif // __GNUC__ && !__ARMCC_VERSION