diff --git a/sandbox/base/main.c b/sandbox/base/main.c
index 18cc69b..2720858 100644
--- a/sandbox/base/main.c
+++ b/sandbox/base/main.c
@@ -13,6 +13,19 @@
 #define ALLOC_START_MB 16
 #define ALLOC_END_MB 18
 
+struct mem_map_region {
+	phys_addr_t base;
+	phys_addr_t limit;
+	enum { REGION_FREE, REGION_RESERVED } status;
+};
+
+static struct mem_map_region mem_map[] = {
+	{ .base = 0x00000000, .limit = 0x0000ffff, .status = REGION_RESERVED },
+	{ .base = 0x00010000, .limit = 0x0004ffff, .status = REGION_FREE },
+	{ .base = 0x00050000, .limit = 0x0005ffff, .status = REGION_RESERVED },
+	{ .base = 0x00060000, .limit = 0x000affff, .status = REGION_FREE },
+};
+
 /* virtual address of where system memory is mapped */
 static void *system_memory = NULL;
 
@@ -38,6 +51,27 @@ int main(int argc, const char **argv)
 		return -1;
 	}
 
+	phys_addr_t pmem_base = UINTPTR_MAX, pmem_limit = 0;
+	size_t nr_mem_map_entries = sizeof mem_map / sizeof mem_map[0];
+
+	for (size_t i = 0; i < nr_mem_map_entries; i++) {
+		if (mem_map[i].base < pmem_base) {
+			pmem_base = mem_map[i].base;
+		}
+
+		if (mem_map[i].limit > pmem_limit) {
+			pmem_limit = mem_map[i].limit;
+		}
+	}
+
+	memblock_add(pmem_base, pmem_limit);
+	
+	for (size_t i = 0; i < nr_mem_map_entries; i++) {
+		if (mem_map[i].status == REGION_RESERVED) {
+			memblock_reserve(mem_map[i].base, mem_map[i].limit);
+		}
+	}
+	
 	printf("allocated %u MiB (0x%zx bytes) of memory to act as system RAM at %p\n", MEMORY_SIZE_MB, MB_TO_BYTES(MEMORY_SIZE_MB), system_memory);
 
 	uintptr_t voffset = (uintptr_t)system_memory;
@@ -48,11 +82,6 @@ int main(int argc, const char **argv)
 
 	memblock_add(0, MB_TO_BYTES(MEMORY_SIZE_MB));
 
-	memblock_reserve(0x00000, 0x40000);
-	memblock_reserve(0x60000, 0x20000);
-	memblock_reserve(0x30000, 0x40000);
-	memblock_reserve(0x100000, 0x10000);
-
 	for (int i = 0; i < 8; i++) {
 		int size = 512 + (rand() % 16384);