From a1eedfa42a930618b5b71b0ca042ff954c65edf0 Mon Sep 17 00:00:00 2001
From: Richard Qin <richard.qin.x@gmail.com>
Date: Sun, 8 Nov 2026 08:12:05 +0800
Subject: [mubios] Add cursor and char service

Signed-off-by: Richard Qin <richard.qin.x@gmail.com>
---
 mubios/services/int10.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 55 insertions(+), 3 deletions(-)

(limited to 'mubios')

diff --git a/mubios/services/int10.c b/mubios/services/int10.c
index 0e63ef2..6793c40 100644
--- a/mubios/services/int10.c
+++ b/mubios/services/int10.c
@@ -24,6 +24,20 @@
 
 #define VGA_TEXT_BASE 0x000B8000u
 #define BDA_CURSOR 0x00000450u
+#define BDA_CURSOR_SHAPE 0x00000460u
+#define VGA_PAGE_SIZE 0x00001000u
+
+static volatile u16 *
+int10_cursor_for_page (u8 page)
+{
+  return (volatile u16 *)(BDA_CURSOR + ((u32)page * 2u));
+}
+
+static volatile u16 *
+int10_video_for_page (u8 page)
+{
+  return (volatile u16 *)(VGA_TEXT_BASE + ((u32)page * VGA_PAGE_SIZE));
+}
 
 static void
 int10_newline (volatile u16 *cursor)
@@ -40,22 +54,60 @@ int10_service (struct bios_regs *regs)
   volatile u16 *cursor;
   volatile u16 *video;
   u8 function;
+  u8 page;
   u8 character;
   u8 attribute;
   u16 position;
+  u16 count;
 
   function = (u8)(regs->eax >> 8);
+  page = (u8)(regs->ebx >> 8);
 
-  if (function != 0x0Eu)
+  if (function == 0x02u)
+    {
+      cursor = int10_cursor_for_page (page);
+      position = (u16)(((u8)(regs->edx >> 8) * 80u) + (u8)regs->edx);
+      *cursor = position;
+      return;
+    }
+
+  if (function == 0x03u)
+    {
+      cursor = int10_cursor_for_page (page);
+      position = *cursor;
+      regs->edx = (regs->edx & 0xFFFF0000u) | ((u32)(position / 80u) << 8)
+                  | (u32)(position % 80u);
+      regs->ecx = (regs->ecx & 0xFFFF0000u) | 0x0607u;
+      return;
+    }
+
+  if (function != 0x09u && function != 0x0Eu)
     return;
 
-  cursor = (volatile u16 *)BDA_CURSOR;
-  video = (volatile u16 *)VGA_TEXT_BASE;
+  cursor = int10_cursor_for_page (page);
+  video = int10_video_for_page (page);
 
   character = (u8)regs->eax;
   attribute = (u8)regs->ebx;
   position = *cursor;
 
+  if (function == 0x09u)
+    {
+      count = (u16)regs->ecx;
+
+      while (count != 0u)
+        {
+          if (position >= 2000u)
+            position = 0;
+
+          video[position] = (u16)character | ((u16)attribute << 8);
+          position++;
+          count--;
+        }
+
+      return;
+    }
+
   if (character == 0x0Du)
     {
       *cursor = (u16)((position / 80u) * 80u);
-- 
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