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libc-hooks: newlib's heap may use entire unused RAM

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Use linker symbol and board configs to determine the start
and extent of remaining RAM present in a board and use
it as newlib's heap.

Change-Id: I7128cf2857664331d83f212f27e8af7ad3bb8936
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
This commit is contained in:
Jithu Joseph 2016-02-22 19:47:06 -08:00 • committed by Gerrit Code Review
commit 4ad7f2a5a3
2 changed files with 18 additions and 12 deletions
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23
lib/libc/newlib/libc-hooks.c
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@ -17,10 +17,23 @@
#include <errno.h>
#include <stdio.h>
#include <sys/stat.h>
#include <linker-defs.h>
#include <misc/util.h>
#define HEAP_SIZE CONFIG_NEWLIB_HEAP_SIZE
unsigned char heap[HEAP_SIZE];
unsigned int heap_sz;
#define USED_RAM_END_ADDR POINTER_TO_UINT(&_end)
#if defined(CONFIG_ARM)
#define USED_RAM_SIZE (USED_RAM_END_ADDR - CONFIG_SRAM_BASE_ADDRESS)
#define MAX_HEAP_SIZE ((KB(CONFIG_SRAM_SIZE)) - USED_RAM_SIZE)
#elif defined(CONFIG_ARC)
#define USED_RAM_SIZE (USED_RAM_END_ADDR - CONFIG_RAM_START)
#define MAX_HEAP_SIZE ((KB(CONFIG_RAM_SIZE)) - USED_RAM_SIZE)
#else /* X86 */
#define USED_RAM_SIZE (USED_RAM_END_ADDR - CONFIG_PHYS_RAM_ADDR)
#define MAX_HEAP_SIZE ((KB(CONFIG_RAM_SIZE)) - USED_RAM_SIZE)
#endif
static unsigned char *heap_base = UINT_TO_POINTER(USED_RAM_END_ADDR);
static unsigned int heap_sz;
static int _stdout_hook_default(int c)
{
@ -126,9 +139,9 @@ int lseek(int file, int ptr, int dir)
void *sbrk(int count)
{
void *ptr = heap + heap_sz;
void *ptr = heap_base + heap_sz;
if ((heap_sz + count) <= HEAP_SIZE) {
if ((heap_sz + count) < MAX_HEAP_SIZE) {
heap_sz += count;
return ptr;
} else {