max80_fw/rv32/sbrk.c

/*
 * sbrk allocator
 */

#include <stddef.h>
#include <errno.h>
#include "sys.h"
#include "common.h"

#define HEAP_SIZE	(4 << 20) /* 4 MB */

static char __attribute__((section(".heap"))) __heap[HEAP_SIZE];
static char *cur_brk = __heap;

void *_sbrk(size_t increment)
{
    char *old_brk = cur_brk;
    char *new_brk = old_brk + increment;

    if (unlikely(new_brk > &__heap[HEAP_SIZE])) {
	errno = ENOMEM;
	return (void *)(-1);
    }

    cur_brk = new_brk;
    return old_brk;
}