#include "heap4_common.h"

#define HEAP_BYTES 160U

static uint8_t heap_area[HEAP_BYTES + HEAP4_ALIGNMENT];
static HeapBlock start;
static HeapBlock *end_marker;

volatile size_t g_initial_free_size;
volatile uintptr_t g_aligned_offset;
volatile int g_end_is_last;

static void heap_init(void)
{
    uintptr_t raw;
    uintptr_t aligned;
    size_t available;
    HeapBlock *first;

    raw = (uintptr_t)&heap_area[0];
    aligned = heap4_align_address(raw);
    available = HEAP_BYTES - (size_t)(aligned - raw);
    available &= ~HEAP4_ALIGNMENT_MASK;

    first = (HeapBlock *)aligned;
    end_marker = (HeapBlock *)(aligned + available - sizeof(HeapBlock));
    end_marker->next = 0;
    end_marker->size = 0U;

    first->next = end_marker;
    first->size = (uint8_t *)end_marker - (uint8_t *)first;

    start.next = first;
    start.size = 0U;
}

int main(void)
{
    heap_init();

    g_aligned_offset = (uintptr_t)start.next - (uintptr_t)&heap_area[0];
    g_initial_free_size = start.next->size;
    g_end_is_last = (start.next->next == end_marker) && (end_marker->next == 0);

    TRACE_PRINTF("offset=%u free=%u end_last=%d\n",
                 (unsigned)g_aligned_offset, (unsigned)g_initial_free_size,
                 g_end_is_last);
    return 0;
}