kernel: mm: Store free regions in a struct

3 files changed, 32 insertions, 1 deletions

diff --git a/kernel/include/mm/memory_map.h b/kernel/include/mm/memory_map.h
index a02daa6..cf798b5 100644
--- a/kernel/include/mm/memory_map.h
+++ b/kernel/include/mm/memory_map.h
@@ -19,8 +19,19 @@
 #ifndef __mm_memory_map_h
 #define __mm_memory_map_h
 
+#include <stdint.h>
+
 #include <mm/multiboot.h>
 
+/* TODO: Practically, do we need more than 32? */
+#define MAX_FREE_REGIONS 32
+
+typedef struct {
+  uint8_t n_regions;
+  multiboot_memory_map_t *region_list[MAX_FREE_REGIONS];
+} free_memory_regions_t;
+
 void memory_map_load(multiboot_info_t *);
+free_memory_regions_t *memory_map_get_free_regions(void);
 
 #endif
diff --git a/kernel/kernel/kernel.c b/kernel/kernel/kernel.c
index 8d19b3b..c999a1e 100644
--- a/kernel/kernel/kernel.c
+++ b/kernel/kernel/kernel.c
@@ -45,6 +45,13 @@ kernel_main(uint32_t magic, multiboot_info_t *multiboot_info)
 
   printk("Kernel", "Started.");
 
+  free_memory_regions_t *free_memory_regions = memory_map_get_free_regions();
+  for (int i = 0; i < free_memory_regions->n_regions; i++)
+    printk("Kernel",
+           "start: 0x%.08x | length: 0x%.08x",
+           free_memory_regions->region_list[i]->addr_low,
+           free_memory_regions->region_list[i]->len_low);
+
   exit();
   halt(); /* If exit() fails (on real hardware) */
 }
diff --git a/kernel/mm/memory_map.c b/kernel/mm/memory_map.c
index 2a8f47b..448cb29 100644
--- a/kernel/mm/memory_map.c
+++ b/kernel/mm/memory_map.c
@@ -23,8 +23,11 @@
 #include <kernel/halt.h>
 #include <libk/stdio.h>
 
+#include <mm/memory_map.h>
 #include <mm/multiboot.h>
 
+free_memory_regions_t free_memory_regions = { 0 };
+
 ALWAYS_INLINE static char *
 memory_map_fetch_type(multiboot_memory_map_t *mmap)
 {
@@ -72,8 +75,12 @@ memory_map_load(multiboot_info_t *multiboot_info)
         = (multiboot_memory_map_t *) (multiboot_info->mmap_addr + i);
 
     total_mem += mmap->len_low;
-    if (mmap->type == MULTIBOOT_MEMORY_AVAILABLE)
+    if (mmap->type == MULTIBOOT_MEMORY_AVAILABLE) {
+      free_memory_regions.region_list[free_memory_regions.n_regions] = mmap;
+      free_memory_regions.n_regions++;
+
       total_available_mem += mmap->len_low;
+    }
 
     printk("mm",
            "start: 0x%.08x | length: 0x%.08x | type: %s",
@@ -85,3 +92,9 @@ memory_map_load(multiboot_info_t *multiboot_info)
   printk("mm", "Total Memory: %lu MiB", total_mem / MiB);
   printk("mm", "Total Available Memory: %lu MiB", total_available_mem / MiB);
 }
+
+free_memory_regions_t *
+memory_map_get_free_regions(void)
+{
+  return &free_memory_regions;
+}