Upload files to "drivers"

drivers/tty.c

@@ -0,0 +1,179 @@
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include <string.h>
+#include <port_io.h>
+#include <vga/vga.h>
+#include <tty.h>
+
+static size_t terminal_row;
+static size_t terminal_column;
+static uint8_t terminal_color;
+static uint16_t* terminal_buffer;
+
+void terminal_initialize(void)
+{
+  terminal_initializec(0x00);
+}
+
+void terminal_initializec(uint8_t color)
+{
+  terminal_row = 0;
+  terminal_column = 0;
+  
+  if (color == 0x00)
+  {
+    terminal_color = vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK);
+  }
+  else {
+    terminal_color = color;
+  }
+  
+  terminal_buffer = VGA_MEMORY;
+  for (size_t y = 0; y < VGA_HEIGHT; y++)
+  {
+    for (size_t x = 0; x < VGA_WIDTH; x++)
+    {
+      const size_t index = y * VGA_WIDTH + x;
+      terminal_buffer[index] = vga_entry(' ', terminal_color);
+    }
+  }
+}
+
+void terminal_setcolor(uint8_t color)
+{
+  terminal_color = color;
+}
+
+uint8_t terminal_getcolor(void)
+{
+  return terminal_color;
+}
+
+void terminal_putentryat(unsigned char c, uint8_t color, size_t x, size_t y)
+{
+  const size_t index = y * VGA_WIDTH + x;
+  terminal_buffer[index] = vga_entry(c, color);
+}
+
+void terminal_putchar(const char c)
+{
+  unsigned char uc = c;
+  
+  if (uc == '\n')
+  {
+    terminal_column = 0;
+    if (++terminal_row == VGA_HEIGHT)
+    {
+      terminal_scroll();
+      terminal_row = VGA_HEIGHT - 1;
+    }
+    return;
+  }
+  else if (uc == '\t')
+  {
+    terminal_column += 4;
+    
+    if (terminal_column >= VGA_WIDTH)
+    {
+      terminal_putchar('\n');
+    }
+    
+    return;
+  }
+	
+  terminal_putentryat(uc, terminal_color, terminal_column, terminal_row);
+  
+  
+  if (++terminal_column == VGA_WIDTH)
+  {
+    terminal_column = 0;
+    if (++terminal_row == VGA_HEIGHT)
+    {
+      terminal_scroll();
+      terminal_row = VGA_HEIGHT - 1;
+    }
+  }
+}
+
+void terminal_write(const char* data, size_t size)
+{
+  for (size_t i = 0; i < size; i++)
+  {
+    terminal_putchar(data[i]);
+  }
+}
+
+void terminal_writestring(const char* data)
+{
+  terminal_write(data, strlen(data));
+}
+
+void terminal_debug_writestring(const char* data)
+{
+  terminal_writestring("[ DEBUG ] ");
+  terminal_writestring(data);
+}
+
+void terminal_writeline(const char* data)
+{
+  terminal_column = 0;
+  terminal_writestring(data);
+}
+
+void terminal_writechar_r(const char ch)
+{
+  unsigned char uch = ch;
+
+  for (size_t i = 0; i < VGA_WIDTH; i++)
+  {
+    terminal_putchar(uch);
+  }
+}
+
+void terminal_clear(void)
+{
+  terminal_clearl(-1);
+}
+
+void terminal_clearl(size_t num_lines)
+{
+  if (num_lines == (size_t)-1)
+  {
+    terminal_initializec(terminal_getcolor());
+  }
+  else
+  {
+    /* XXX note to self: VGA_HEIGHT is 25, and VGA_WIDTH is 80 XXX */
+    /* static size_t terminal_row; static size_t terminal_column; */
+    
+    terminal_row = VGA_HEIGHT;
+    terminal_column = 0;
+    
+    while (terminal_row < num_lines)
+    {
+      terminal_writechar_r(' ');
+      terminal_row -= 1;
+    }
+  }
+}
+
+void terminal_scroll(void)
+{
+  for (size_t y = 1; y < VGA_HEIGHT; y++)
+  {
+    for (size_t x = 0; x < VGA_WIDTH; x++)
+    {
+      const size_t src_index = y * VGA_WIDTH + x;
+      const size_t dst_index = (y - 1) * VGA_WIDTH + x;
+      terminal_buffer[dst_index] = terminal_buffer[src_index];
+    }
+  }
+
+  for (size_t x = 0; x < VGA_WIDTH; x++)
+  {
+    const size_t index = (VGA_HEIGHT - 1) * VGA_WIDTH + x;
+    terminal_buffer[index] = (terminal_color << 8) | ' ';
+  }
+}