Clear message at bootup without extra ascii characters

3 files changed, 23 insertions, 12 deletions

diff --git a/src/common/common.asm b/src/common/common.asm
index a98ef67..87444db 100644
--- a/src/common/common.asm
+++ b/src/common/common.asm
@@ -13,7 +13,7 @@
 %define VGA_COLOR_BLACK 0
 %define VGA_COLOR_GREEN 2
 %define VGA_COLOR_RED 4
-%define VGA_WHITE_ON_BLACK 0x0f20
+%define VGA_WHITE_ON_BLACK 0x0f
 %define VGA_BUFFER 0xb8000
 %define VGA_SCREEN_X 80
 %define VGA_SCREEN_Y 25
diff --git a/src/common/common.protmode.clear.asm b/src/common/common.protmode.clear.asm
index 47cb980..8d26e2f 100644
--- a/src/common/common.protmode.clear.asm
+++ b/src/common/common.protmode.clear.asm
@@ -1,13 +1,18 @@
 ;; common.protmode.print.asm
 
+%ifndef COMMON_PROTMODE_CLEAR_ASM
+%define COMMON_PROTMODE_CLEAR_ASM
+
 %include "common.asm"
 
 _clear_screen:  
         mov edi, VGA_BUFFER
         mov ecx, VGA_SCREEN
-        mov ax, VGA_WHITE_ON_BLACK
+        mov ax, 0x0f20          ; Empty char with white on black
 .clear:
-        mov [edi], eax
+        mov [edi], ax
         add edi, 2
         loop .clear
         ret
+
+%endif
diff --git a/src/common/common.protmode.print.asm b/src/common/common.protmode.print.asm
index 5995e69..82ed3f4 100644
--- a/src/common/common.protmode.print.asm
+++ b/src/common/common.protmode.print.asm
@@ -1,11 +1,13 @@
 ;; common.protmode.print.asm
+%ifndef COMMON_PROTMODE_PRINT_ASM
+%define COMMON_PROTMODE_PRINT_ASM
 
 %include "common.asm"
 
 _print_string_pm_vga:   
         pusha
         mov edi, VGA_BUFFER
-        mov ah, WB_COLOR
+        mov ah, VGA_WHITE_ON_BLACK
         xor ecx, ecx
         xor edx, edx
 
@@ -14,22 +16,26 @@ _print_string_pm_vga:
         test al, al
         jz .done
 
-        push eax
-        mov eax, edx
-        imul eax, eax, 160
-        lea edi, [VGA_BUFFER + eax]
-        lea edi, [edi + ecx * 2]
-        pop eax
+        mov ebx, edx
+        imul ebx, ebx, 160
+        lea ebx, [VGA_BUFFER + ebx + ecx * 2]
+        
+        mov ah, VGA_WHITE_ON_BLACK
+        mov [ebx], ax
         
 ;; Advance cursor
         inc cl
-        cmp cl, 80
-        jb .print_loop
+        cmp cl, 80              ; Check if screen is full X pos
+        jne .print_loop
         xor cl, cl
         inc dl
+        cmp dl, 25
+        jb .print_loop          ; Check if screen is full Y pos
 
         jmp .print_loop
         
 .done:
         popa
         ret
+
+%endif