tnc3-firmware/newlib/_sbrk.c

66 wiersze
1.6 KiB
C

//
// This file is part of the µOS++ III distribution.
// Copyright (c) 2014 Liviu Ionescu.
//
// ----------------------------------------------------------------------------
#include <sys/types.h>
#include <errno.h>
// ----------------------------------------------------------------------------
caddr_t
_sbrk(int incr);
// ----------------------------------------------------------------------------
// The definitions used here should be kept in sync with the
// stack definitions in the linker script.
caddr_t
_sbrk(int incr)
{
extern char _Heap_Begin; // Defined by the linker.
extern char _Heap_Limit; // Defined by the linker.
static char* current_heap_end = 0;
char* current_block_address;
if (current_heap_end == 0)
{
current_heap_end = &_Heap_Begin;
}
current_block_address = current_heap_end;
// Need to align heap to word boundary, else will get
// hard faults on Cortex-M0. So we assume that heap starts on
// word boundary, hence make sure we always add a multiple of
// 4 to it.
incr = (incr + 3) & (~3); // align value to 4
if (current_heap_end + incr > &_Heap_Limit)
{
// Some of the libstdc++-v3 tests rely upon detecting
// out of memory errors, so do not abort here.
#if 0
extern void abort (void);
_write (1, "_sbrk: Heap and stack collision\n", 32);
abort ();
#else
// Heap has overflowed
errno = ENOMEM;
return (caddr_t) - 1;
#endif
}
current_heap_end += incr;
return (caddr_t) current_block_address;
}
// ----------------------------------------------------------------------------