Add comments to explain CGA ports better

5 files changed, 2 insertions, 197 deletions

diff --git a/src/kernel.cc b/src/kernel.cc
index 4569107..4c17969 100644
--- a/src/kernel.cc
+++ b/src/kernel.cc
@@ -10,15 +10,15 @@
 
 #include <stdlib.h>
 #include <types.h>
+#include "cga.h"
 #include "gdt.h"
-#include "vga.h"
 
 extern "C" {
 void dump_multiboot(uint32_t mb_magic, uint32_t mb_addr);
 void dump_gdt();
 
 void kernel_main([[maybe_unused]] uint32_t mb_magic, [[maybe_unused]] uint32_t mb_addr) {
-  VGA terminal;
+  CGA terminal;
   Console::set(&terminal);
 
   printk("Hello, kernel World!\n");
diff --git a/src/makefile b/src/makefile
index 25c58be..8214d03 100644
--- a/src/makefile
+++ b/src/makefile
@@ -4,6 +4,5 @@ CXX_OBJ += src/kernel.o \
 	   src/kernel/dump_gdt.o \
 	   src/kernel/dump_multiboot.o \
 	   src/memory.o \
-	   src/vga.o \
 	   src/gdt.o \
 	   src/gdt/segmentdescriptor.o
diff --git a/src/ports.h b/src/ports.h
deleted file mode 100644
index 0371bcc..0000000
--- a/src/ports.h
+++ /dev/null
@@ -1,43 +0,0 @@
-#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
deleted file mode 100644
index 66a6b3a..0000000
--- a/src/vga.cc
+++ /dev/null
@@ -1,92 +0,0 @@
-#include "vga.h"
-#include <string.h>
-
-static_assert(sizeof(VGA::Entry) == 2);
-
-VGA::VGA(vga_color fg, vga_color bg, uint32_t address) : color_fg(fg), color_bg(bg) {
-  buffer = reinterpret_cast<Entry*>(address);
-
-  // clear buffer
-  for (size_t y = 0; y < max_rows; y++) {
-    for (size_t x = 0; x < max_columns; x++) {
-      const size_t index = y * max_columns + x;
-      buffer[index].c = ' ';
-      buffer[index].fg = color_fg;
-      buffer[index].bg = color_bg;
-    }
-  }
-
-  enable_cursor(14, 15);
-  update_cursor();
-}
-
-void VGA::set_color(vga_color fg, vga_color bg) {
-  color_fg = fg;
-  color_bg = bg;
-  for (size_t y = 0; y < max_rows; y++) {
-    for (size_t x = 0; x < max_columns; x++) {
-      const size_t index = y * max_columns + x;
-      buffer[index].fg = color_fg;
-      buffer[index].bg = 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':
-      column = 0;
-      ++row;
-      break;
-    default: {
-      const size_t index = row * max_columns + column;
-      buffer[index].c = c;
-      ++column;
-    }
-  }
-
-  if (column == max_columns) {
-    column = 0;
-    ++row;
-  }
-
-  if (row == max_rows) {
-    // scroll up - move rows 1~25 up by one
-    for (size_t y = 1; y < max_rows; y++) {
-      const auto prev_y = y - 1;
-      for (size_t x = 0; x < max_columns; ++x) {
-        const auto prev = prev_y * max_columns + x;
-        const auto idx = y * max_columns + x;
-        buffer[prev] = buffer[idx];
-      }
-    }
-    --row;
-  }
-}
-
-void VGA::write(ViewIterator& iter) {
-  while (iter) {
-    write(iter.next());
-  }
-}
diff --git a/src/vga.h b/src/vga.h
deleted file mode 100644
index 7a8c755..0000000
--- a/src/vga.h
+++ /dev/null
@@ -1,59 +0,0 @@
-#pragma once
-#include <stdlib.h>
-#include "ports.h"
-
-class VGA : public Console {
-public:
-  /* Hardware text mode color constants. */
-  enum vga_color : uint8_t {
-    VGA_COLOR_BLACK = 0,
-    VGA_COLOR_BLUE = 1,
-    VGA_COLOR_GREEN = 2,
-    VGA_COLOR_CYAN = 3,
-    VGA_COLOR_RED = 4,
-    VGA_COLOR_MAGENTA = 5,
-    VGA_COLOR_BROWN = 6,
-    VGA_COLOR_LIGHT_GREY = 7,
-    VGA_COLOR_DARK_GREY = 8,
-    VGA_COLOR_LIGHT_BLUE = 9,
-    VGA_COLOR_LIGHT_GREEN = 10,
-    VGA_COLOR_LIGHT_CYAN = 11,
-    VGA_COLOR_LIGHT_RED = 12,
-    VGA_COLOR_LIGHT_MAGENTA = 13,
-    VGA_COLOR_LIGHT_BROWN = 14,
-    VGA_COLOR_WHITE = 15,
-  };
-
-  VGA(vga_color fg = VGA_COLOR_BLACK, vga_color bg = VGA_COLOR_LIGHT_GREY, uint32_t address = 0xB8000);
-  ~VGA() = default;
-
-  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;
-
-
-  struct Entry {
-    char c;
-    vga_color fg : 4;
-    vga_color bg : 4;
-  } __attribute((packed));
-
-private:
-  const size_t max_columns = 80, max_rows = 25;
-  size_t column = 0, row = 0;
-
-  vga_color color_fg;
-  vga_color color_bg;
-
-  Entry* buffer;
-
-  // ports
-  vga_horizontal_total p_3d4;
-  vga_horizontal_display_enable_end p_3d5;
-};
-