1 files changed, 41 insertions, 0 deletions
diff --git a/multiboot.cpp b/multiboot.cpp
new file mode 100644
index 0000000..0c34984
--- /dev/null
+++ b/multiboot.cpp
@@ -0,0 +1,41 @@
+#include "textoutput.hpp"
+
+#include <cstdint>
+
+extern TextOutput& term;
+
+std::uint32_t multiboot_magic;
+std::uint32_t *multiboot_ptr;
+
+std::uint32_t lowerMem = 0;
+std::uint32_t upperMem = 0;
+
+bool multiboot_initialize()
+{
+    if (multiboot_magic != 0x36d76289) {
+        term.write("Not multiboot!");
+        return false;
+    }
+
+    term.write("Found multiboot headers: ");
+
+    auto ptr = multiboot_ptr + 2;
+    while (ptr[0] != 0 && ptr[1] != 8) {
+        term.write(ptr[0]);
+        term.write(", ");
+
+        if (ptr[0] == 4) {
+            lowerMem = ptr[2] * 1024;
+            upperMem = ptr[3] * 1024;
+        }
+    
+        auto next = reinterpret_cast<std::uintptr_t>(ptr);
+        next += ptr[1];
+        next = (next + 7) & ~7;
+        ptr = reinterpret_cast<std::uint32_t *>(next);
+    }
+
+    term.write('\n');
+    return true;
+}
+