Update VGA cursor position on printk

5 files changed, 82 insertions, 1 deletions

diff --git a/src/gdt.h b/src/gdt.h
index 274cb6a..a86a14f 100644
--- a/src/gdt.h
+++ b/src/gdt.h
@@ -2,7 +2,11 @@
 
 #include <types.h>
 
-/* From OSDev wiki:
+/*
+ * http://lowlevel.eu/wiki/Global_Descriptor_Table
+ * https://wiki.osdev.org/GDT_Tutorial
+ *
+ * From OSDev wiki:
  *
  * Segment
  * a logically contiguous chunk of memory with consistent properties (CPU's speaking)
diff --git a/src/memory.cc b/src/memory.cc
index 0dbf3d0..a2a2561 100644
--- a/src/memory.cc
+++ b/src/memory.cc
@@ -2,4 +2,5 @@
 
 void operator delete(void*) {
   printk("Calling delete\n");
+  abort();
 }
diff --git a/src/ports.h b/src/ports.h
new file mode 100644
index 0000000..0371bcc
--- /dev/null
+++ b/src/ports.h
@@ -0,0 +1,43 @@
+#pragma once
+
+template <typename T>
+concept port_data_t = (is_same<T, uint8_t>::value || is_same<T, uint16_t>::value || is_same<T, uint32_t>::value);
+
+template <uint16_t port_num, port_data_t T>
+class Port {
+public:
+  [[nodiscard]] T read() {
+    T result;
+
+    switch (sizeof(T)) {
+      case 1:
+        asm volatile("inb %1, %0" : "=a"(result) : "Nd"(port_num));
+        break;
+      case 2:
+        asm volatile("inw %1, %0" : "=a"(result) : "Nd"(port_num));
+        break;
+      case 4:
+        asm volatile("inl %1, %0" : "=a"(result) : "Nd"(port_num));
+        break;
+    }
+
+    return result;
+  }
+
+  void write(T data) {
+    switch (sizeof(T)) {
+      case 1:
+        asm volatile("outb %0, %1" : : "a"(data), "Nd"(port_num));
+        break;
+      case 2:
+        asm volatile("outw %0, %1" : : "a"(data), "Nd"(port_num));
+        break;
+      case 4:
+        asm volatile("outl %0, %1" : : "a"(data), "Nd"(port_num));
+        break;
+    }
+  }
+};
+
+typedef Port<0x3d4, uint8_t> vga_horizontal_total;
+typedef Port<0x3d5, uint8_t> vga_horizontal_display_enable_end;
diff --git a/src/vga.cc b/src/vga.cc
index 6b64b98..66a6b3a 100644
--- a/src/vga.cc
+++ b/src/vga.cc
@@ -15,6 +15,9 @@ VGA::VGA(vga_color fg, vga_color bg, uint32_t address) : color_fg(fg), color_bg(
       buffer[index].bg = color_bg;
     }
   }
+
+  enable_cursor(14, 15);
+  update_cursor();
 }
 
 void VGA::set_color(vga_color fg, vga_color bg) {
@@ -29,6 +32,27 @@ void VGA::set_color(vga_color fg, vga_color bg) {
   }
 }
 
+void VGA::enable_cursor(uint8_t start, uint8_t end) {
+  p_3d4.write(0x0a);
+  p_3d5.write((p_3d5.read() & 0xc0) | start);
+
+  p_3d4.write(0x0b);
+  p_3d5.write((p_3d5.read() & 0xe0) | end);
+}
+void VGA::disable_cursor() {
+  p_3d4.write(0x0a);
+  p_3d5.write(0x20);
+}
+void VGA::update_cursor() {
+  const uint16_t pos = row * max_columns + column;
+
+  p_3d4.write(0x0f);
+  p_3d5.write(static_cast<uint8_t>(pos & 0xff));
+
+  p_3d4.write(0x0e);
+  p_3d5.write(static_cast<uint8_t>((pos >> 8) & 0xff));
+}
+
 void VGA::write(char c) {
   switch (c) {
     case '\n':
diff --git a/src/vga.h b/src/vga.h
index 32c152f..7a8c755 100644
--- a/src/vga.h
+++ b/src/vga.h
@@ -1,5 +1,6 @@
 #pragma once
 #include <stdlib.h>
+#include "ports.h"
 
 class VGA : public Console {
 public:
@@ -28,6 +29,10 @@ public:
 
   void set_color(vga_color fg, vga_color bg);
 
+  void enable_cursor(uint8_t start, uint8_t end);
+  void disable_cursor();
+  void update_cursor() override;
+
   void write(char c) override;
   void write(ViewIterator& iter) override;
 
@@ -46,5 +51,9 @@ private:
   vga_color color_bg;
 
   Entry* buffer;
+
+  // ports
+  vga_horizontal_total p_3d4;
+  vga_horizontal_display_enable_end p_3d5;
 };