From 54476eeea1e93d3df0bd4847b76915def6e4da59 Mon Sep 17 00:00:00 2001
From: Thomas Oltmann <thomas.oltmann.hhg@gmail.com>
Date: Fri, 4 Jul 2025 16:33:05 +0200
Subject: [PATCH] Working on e820 memory map

---
 lboot.S | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/lboot.S b/lboot.S
index 0636bdc..5274e6f 100644
--- a/lboot.S
+++ b/lboot.S
@@ -24,6 +24,10 @@ _start:     cli
             call        print
             call        unreal
 
+            mov         $msg_memmap, %si
+            call        print
+            call        memmap
+
             mov         $msg_fin, %si
             call        print
 1:          hlt
@@ -67,6 +71,23 @@ unreal:     push        %ds
 2:          pop         %ds
             ret
 
+memmap:     push        %bp
+            mov         %sp, %bp
+            sub         $24, %sp
+
+            mov         %ss, %ax
+            mov         %ax, %es
+            mov         %sp, %di
+            xor         %ebx, %ebx
+            mov         $0x534D4150, %edx
+            mov         $24, %ecx
+            mov         $0xE820, %eax
+            int         $0x15
+
+            mov         %bp, %sp
+            pop         %bp
+            ret
+
 print:      xor         %bx, %bx
 
 1:          mov         $COM1+5, %dx
@@ -115,4 +136,5 @@ gdt_ptr:    .word       gdt_size-1
 msg_start:  .asciz      "Netboot via fernlader v1 ...\r\n"
 msg_a20:    .asciz      " * Enabling A20\r\n"
 msg_unreal: .asciz      " * Unreal Mode\r\n"
+msg_memmap: .asciz      " * Fetching Memory Map\r\n"
 msg_fin:    .asciz      "Finished.\r\n"