Memory Zones

First draft of memory zone functionality. Can create a zone and allocate
you memory from the zone. Also has the ability to clear zones and to
free. There is no way yet to free anything that has been allocated on
the zones.

quantum/src/memory/zone.c

@@ -0,0 +1,66 @@
+#include <stdlib.h> // malloc() free()
+#include <stdio.h> // printf()
+
+#include "../defines.h"
+#include "zone.h"
+
+typedef struct ZoneHeader {
+  u64 capacity;
+  u64 cur_size;
+} ZoneHeader;
+
+Zone * zoneCreate(size_t sizeBytes) {
+  // First we need to get a block of memory from the OS
+  // This block needs to include the size of what we want to store
+  // plus the size of our ZoneHeader
+  void *mem_block = malloc(sizeBytes + sizeof(ZoneHeader));
+
+  // Now that we have the block let's get the addresses
+  // for where the header is, and the offset where the data starts
+  ZoneHeader *zone_header = (ZoneHeader *)mem_block;
+  Zone *zone_addr = (Zone *)(zone_header + sizeof(ZoneHeader));
+
+  // Initialize the values of the header
+  zone_header->capacity = sizeBytes;
+  zone_header->cur_size = 0;
+
+  return zone_addr;
+}
+
+void * zoneAlloc(Zone *zone, size_t sizeBytes) {
+  ZoneHeader *zone_header = (ZoneHeader *)zone - sizeof(ZoneHeader);
+
+  if (zone_header->cur_size + sizeBytes > zone_header->capacity) {
+    printf("Could not allocate, not enough space.");
+    return NULL;
+  }
+
+  void *new_mem = (char *)zone + zone_header->cur_size;
+
+  zone_header->cur_size += sizeBytes;
+
+  printf("Zone Header Information:\n");
+  printf("Current Size: %u\n", zone_header->cur_size);
+  printf("Total Capacity: %u\n", zone_header->capacity);
+
+  return new_mem;
+}
+
+void zoneClear(Zone *zone) {
+  ZoneHeader *zone_header = (ZoneHeader *)zone - sizeof(ZoneHeader);
+
+  zone_header->cur_size = 0;
+
+  printf("Zone Header Information:\n");
+  printf("Current Size: %u\n", zone_header->cur_size);
+  printf("Total Capacity: %u\n", zone_header->capacity);
+}
+
+void zoneDestroy(Zone *zone) {
+  // First we need to go back to the beginning of the header as we returned
+  // an offset for the user to use
+  void *del_mem = (ZoneHeader *)zone - sizeof(ZoneHeader);
+
+  // Free the memory
+  free(del_mem);
+}