From a5530f90f06f60794851f24b57cd2ddb05c9a4af Mon Sep 17 00:00:00 2001
From: Andreas Baumann <mail@andreasbaumann.cc>
Date: Mon, 1 May 2017 20:42:35 +0200
Subject: more fooling around with VGA module

---
 doc/LINKS.TODO |  5 +++++
 src/kernel.c   | 13 +++++++++++--
 src/vga.c      | 16 ++++++++++++++--
 src/vga.h      |  1 +
 4 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/doc/LINKS.TODO b/doc/LINKS.TODO
index 76e88a7..65e754f 100644
--- a/doc/LINKS.TODO
+++ b/doc/LINKS.TODO
@@ -1 +1,6 @@
 https://github.com/cs107e/cs107e.github.io
+http://wiki.osdev.org/Calling_Conventions
+http://wiki.osdev.org/Linker_Scripts
+http://wiki.osdev.org/Printing_To_Screen
+http://wiki.osdev.org/Exceptions#General_Protection_Fault
+https://en.wikipedia.org/wiki/X86_calling_conventions
diff --git a/src/kernel.c b/src/kernel.c
index de14d8f..60d0dd3 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -13,7 +13,7 @@ void entry( void )
 	volatile char msg[] = "ABAOS";
 	vga_put_string_at( &vga, 0, 0, (const char *)msg );
 	// doesn't work
-	vga_put_string_at( &vga, 0, 1, "ABAOS2" );
+	//~ vga_put_string_at( &vga, 0, 1, "ABAOS2" );
 	
 	// clang 4.0.0 needs volatile otherwise it takes a random value
 	// from the register in the second vga_put_char_at below??!
@@ -26,7 +26,7 @@ void entry( void )
 			pos++;
 		}
 		vga_put_char_at( &vga, pos, 0, bar[i%4] );
-		for( int j = 0; j < 3000; j++ ) {
+		for( int j = 0; j < 1500; j++ ) {
 		}
 	}
 	vga_put_char_at( &vga, pos, 0, '.' );	
@@ -34,4 +34,13 @@ void entry( void )
 	vga_set_color( &vga, VGA_COLOR_WHITE );
 	vga_set_background_color( &vga, VGA_COLOR_RED );
 	vga_clear_screen( &vga );
+
+	for( int i = 0; i < 50; i++ ) {
+		for( int j = 0; j < i; j++ ) {
+			vga_put_char( &vga, '-' );
+		}
+		vga_put_char( &vga, '>' );
+		vga_put_string( &vga, (const char *)msg );
+		vga_put_newline( &vga );
+	}
 }
diff --git a/src/vga.c b/src/vga.c
index 0133ddf..524b6d7 100644
--- a/src/vga.c
+++ b/src/vga.c
@@ -30,7 +30,7 @@ void vga_clear_screen( vga_t *vga )
 		*(VIDEO_MEMORY+i+1) = calculate_color_cell( vga );
 	}
 	
-	//~ vga_set_cursor( vga, 0, 0 );
+	vga_set_cursor( vga, 0, 0 );
 }
 
 void vga_set_cursor( vga_t *vga, const int x, const int y )
@@ -102,7 +102,7 @@ void vga_put_char( vga_t *vga, const char c )
 		vga->cursor_y++;
 		if( vga->cursor_y >= vga->res_y ) {
 			// TODO: implement scrolling
-			vga->res_y = 0;
+			vga->cursor_y = 0;
 		}
 	}
 }
@@ -114,3 +114,15 @@ void vga_put_string( vga_t *vga, const char *s )
 	}
 }
 
+void vga_put_newline( vga_t *vga )
+{
+	vga->cursor_x = 0;
+	vga->cursor_y++;
+	if( vga->cursor_y >= vga->res_y ) {
+		// TODO: implement scrolling
+		vga->cursor_y = 0;
+	}
+}
+
+
+
diff --git a/src/vga.h b/src/vga.h
index 9664e2c..5ecd88e 100644
--- a/src/vga.h
+++ b/src/vga.h
@@ -43,5 +43,6 @@ void vga_put_char_at( vga_t *vga, const int x, const int y, const char c );
 void vga_put_string_at( vga_t *vga, const int x, const int y, const char *s );
 void vga_put_char( vga_t *vga, const char c );
 void vga_put_string( vga_t *vga, const char *s );
+void vga_put_newline( vga_t *vga );
  
 #endif /* VGA_H */
-- 
cgit v1.2.3-54-g00ecf