Add multiboot header and test read some info

src/head.asm

@@ -56,6 +56,9 @@ _start:
 	; our stack (as it grows downwards).
 	mov esp, stack_top
 
+	push eax 		; Multiboot magic number
+	push ebx		; Multiboot info struct
+
 	; We are now ready to actually execute C code. We cannot embed that in an
 	; assembly file, so we'll create a kernel.c file in a moment. In that file,
 	; we'll create a C entry point called kernel_main and call it here.

src/kern.c

-#include <stdbool.h> /* C doesn't have booleans by default. */
+/*
+  kern.c is where the c code starts, as invoked by our heading
+  assembly. It should only contain high level code
+*/
+
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ -9,11 +14,10 @@
 #include "gdt.h"
 #include "idt.h"
 #include "test.h"
+#include "multiboot.h"
 
-#if defined(__cplusplus)
-extern "C" /* Use C linkage for kernel_main. */
-#endif
-void kernel_main() 
+// The parameters passed here ultimately come through the bootloader
+void kernel_main(multiboot_info* mbd, uint32_t magic)
 {
     /* Initialize terminal and serial interfaces */
     terminal_initialize();
@@ -29,6 +33,11 @@ void kernel_main()
     terminal_writestring("Hello, kernel World!\n");
     //serial_writestring("Second Serial Test\n");
 
+    serial_hexstring(&magic, 4);
+    serial_writestring("\n");
+    serial_hexstring(&(mbd->flags), 8);
+    serial_writestring("\n");
+
     // Enable paging of memory. For now there is only one virtual
     // memory space defined by page_dir
     page_directory_entry* page_dir;