From ca5c11023cb519a5ce93c0691f67043735e849cf Mon Sep 17 00:00:00 2001
From: Baptiste Wicht <baptiste.wicht@gmail.com>
Date: Thu, 31 Oct 2013 13:44:11 +0100
Subject: [PATCH] Verify if the e820 call is valid

---
 micro_kernel/micro_kernel.asm | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/micro_kernel/micro_kernel.asm b/micro_kernel/micro_kernel.asm
index 015cd9c4..0dca7578 100644
--- a/micro_kernel/micro_kernel.asm
+++ b/micro_kernel/micro_kernel.asm
@@ -53,13 +53,14 @@ e820_mmap:
 
     .e820f:
     mov  [e820_entry_count], bp
+
     clc
+    popa
+    ret
 
     .failed:
     stc
-
     popa
-
     ret
 
 _start:
@@ -72,6 +73,8 @@ _start:
     cli
 
     call e820_mmap
+    setc al
+    mov [e820_failed], al
 
     ; Load GDT
     lgdt [GDTR64]
@@ -145,10 +148,12 @@ pm_start:
 [BITS 64]
 
 lm_start:
-    movzx r8, word [e820_entry_count]
+    movzx r8, byte [e820_failed]
     call set_current_position
     call print_int_normal
 
+    jmp $
+
     ; Install IDT
     call install_idt
 
@@ -212,12 +217,15 @@ GDTR64:
     dw 4 * 8 - 1 ; Length of GDT
     dd GDT64
 
-e820_memory_map:
-    times 32 dq 0, 0, 0
+e820_failed:
+    db 0
 
 e820_entry_count:
     dw 0
 
+e820_memory_map:
+    times 32 dq 0, 0, 0
+
 ; Fill the sector (not necessary, but cleaner)
 
    times 16384-($-$$) db 0