read basic mem info

1 files changed, 26 insertions, 8 deletions

diff --git a/arch/x86_64/src/kernel/main.cpp b/arch/x86_64/src/kernel/main.cpp
index e77818e..8ca577a 100644
--- a/arch/x86_64/src/kernel/main.cpp
+++ b/arch/x86_64/src/kernel/main.cpp
@@ -10,16 +10,34 @@ namespace teachos::arch::kernel
   {
     using namespace video::vga;
 
-    auto t = arch::boot::multiboot_information_pointer;
-    // auto multiboot_tag = (struct multiboot_tag *) ((uint8_t) t + 8);
-    // for (auto tag = multiboot_tag; tag->type != )
-
-    if (t == 300)
-    {
-    }
-
     text::clear();
     text::cursor(false);
     text::write("TeachOS is starting up...", text::common_attributes::green_on_black);
+
+    auto mip = arch::boot::multiboot_information_pointer;
+
+    // Address of the first multiboot tag
+    auto multiboot_tag = (struct multiboot_tag *)((uint8_t *)mip + 8);
+
+    /*
+     * Loop over the multiboot2 tags to access the information needed.
+     * Tags are defined in the header.
+     */
+    for (auto tag = multiboot_tag; tag->type != MULTIBOOT_TAG_TYPE_END;
+         tag = (struct multiboot_tag *)((uint8_t *)tag + ((tag->size + 7) & ~7)))
+    {
+      switch (tag->type)
+      {
+        case MULTIBOOT_TAG_TYPE_BASIC_MEMINFO:
+          uint32_t size = tag->size;
+          uint32_t mem_lower = *(uint32_t *)(&size + 32);
+          uint32_t mem_upper = *(uint32_t *)(&size + 64);
+          if (mem_lower > mem_upper)
+          {
+          }
+          text::write("BUFFER IS HERE", text::common_attributes::green_on_black);
+          break;
+      }
+    }
   }
 }  // namespace teachos::arch::kernel