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src/arch/x86_64/memory/mmap.c

@@ -0,0 +1,52 @@
+#include "mmap.h"
+#include "../../api.h"
+#include <stddef.h>
+#include <stdio.h>
+
+#define USABLE_REGION_SIZE 32
+
+memory_map_t memory_map;
+
+static memory_region_t usable_regions[USABLE_REGION_SIZE];
+
+void map_memory(multiboot_info_t* info)
+{
+    if (!(info->flags & (1 << 6)))
+    {
+        printf("Invalid memory map given by bootloader\n");
+        panic();
+    }
+
+    size_t num_regions = 0;
+
+    uint64_t offset = 0;
+    while (offset < info->mmap_length)
+    {
+        multiboot_memory_map_t* mmmt = (multiboot_memory_map_t*)(info->mmap_addr + offset);
+
+        if (mmmt->type == MULTIBOOT_MEMORY_AVAILABLE)
+        {
+            if (num_regions < USABLE_REGION_SIZE)
+            {
+                usable_regions[num_regions] = (memory_region_t){
+                    .base_address = mmmt->addr,
+                    .length = mmmt->len,
+                };
+
+                num_regions++;
+            }
+            else
+            {
+                printf("System has more memory than the memory map can hold\n");
+                break;
+            }
+        }
+
+        offset += mmmt->size + sizeof(mmmt->size);
+    }
+
+    memory_map = (memory_map_t){
+        .num_regions = num_regions,
+        .regions = usable_regions,
+    };
+}