From eb4de24523e8f0832daae89a083844c8e9a261e9 Mon Sep 17 00:00:00 2001
From: James Barnett <noreply@jamesbarnett.xyz>
Date: Sun, 26 May 2019 17:32:25 +0100
Subject: Explicitly enable hardware cursor

Required for virtualbox
---
 kernel/gpu/text_mode/display.c | 24 +++++++++++++++++-------
 kernel/gpu/text_mode/display.h |  1 +
 2 files changed, 18 insertions(+), 7 deletions(-)

(limited to 'kernel/gpu')

diff --git a/kernel/gpu/text_mode/display.c b/kernel/gpu/text_mode/display.c
index 19074f7..bacd9df 100644
--- a/kernel/gpu/text_mode/display.c
+++ b/kernel/gpu/text_mode/display.c
@@ -9,15 +9,15 @@ int cursor_pos = 0;
 int char_attribute_byte = 0x0F;
 
 extern void write_port(unsigned short port, unsigned char data);
+extern char read_port(unsigned short port);
 
-void scrn_clear()
+void scrn_enable_cursor(unsigned char start_line, unsigned char end_line)
 {
-  for (int i = 0; i < FRAME_SIZE; i = i + 2)
-  {
-    video_ram[i] = 0;
-    video_ram[i + 1] = char_attribute_byte;
-  };
-  cursor_pos = 0;
+	write_port(0x3D4, 0x0A);
+	write_port(0x3D5, (read_port(0x3D5) & 0xC0) | start_line);
+ 
+	write_port(0x3D4, 0x0B);
+	write_port(0x3D5, (read_port(0x3D5) & 0xE0) | end_line);
 }
 
 void scrn_update_csr()
@@ -29,6 +29,16 @@ void scrn_update_csr()
     write_port(0x3D5, csr);
 }
 
+void scrn_clear()
+{
+  for (int i = 0; i < FRAME_SIZE; i = i + 2)
+  {
+    video_ram[i] = 0;
+    video_ram[i + 1] = char_attribute_byte;
+  };
+  cursor_pos = 0;
+}
+
 void scrn_print(char *msg)
 {
   int j = 0;
diff --git a/kernel/gpu/text_mode/display.h b/kernel/gpu/text_mode/display.h
index f4f3724..fec3314 100644
--- a/kernel/gpu/text_mode/display.h
+++ b/kernel/gpu/text_mode/display.h
@@ -1,3 +1,4 @@
+void scrn_enable_cursor(unsigned char start_line, unsigned char end_line);
 void scrn_clear();
 void scrn_print(char *msg);
 void scrn_println(char *msg);
-- 
cgit v1.2.3