Add VGA driver

drivers/x86_64/vga.c

@@ -0,0 +1,84 @@
+#include <grub/text_fb_info.h>
+#include "../vga.h"
+#include "../../cpu/x86_64/ports.h"
+#include <string.h>
+#include <stddef.h>
+#define xy_to_indx(x,y) ((x+(y*width))*2)
+static char* screen;
+static int width;
+static int height;
+static int x;
+static int y;
+static vga_colors fg_color;
+static vga_colors bg_color;
+
+static void set_char(int x,int y,char c) {
+  screen[xy_to_indx(x,y)]=c;
+  screen[xy_to_indx(x,y)+1]=(bg_color<<4)|fg_color;
+}
+
+void vga_clear() {
+  for (int y=0;y<height;y++) {
+    for (int x=0;x<width;x++) {
+      set_char(x,y,' ');
+    }
+  }
+}
+
+static void set_cursor(int x,int y) {
+  int pos=(x+(y*width));
+  port_byte_out(0x3D4,0xF);
+  port_byte_out(0x3D5,pos&0xFF);
+  port_byte_out(0x3D4,0xE);
+  port_byte_out(0x3D5,(pos&0xFF00)>>8);
+}
+
+void vga_init(text_fb_info framebuffer_info) {
+  x=0;
+  y=0;
+  fg_color=VGA_WHITE;
+  bg_color=VGA_BLACK;
+  screen=framebuffer_info.address;
+  width=framebuffer_info.width;
+  height=framebuffer_info.height;
+  port_byte_out(0x3D4,0xA);
+  port_byte_out(0x3D5,(port_byte_in(0x3D5)&0xC0)|14);
+  port_byte_out(0x3D4,0xB);
+  port_byte_out(0x3D5,(port_byte_in(0x3D5)&0xE0)|15);
+  set_cursor(0,0);
+  vga_clear();
+}
+
+void vga_write_string(const char* string) {
+  for (size_t i=0;i<strlen(string);i++) {
+    char c=string[i];
+    if (c=='\n') {
+      x=0;
+      y++;
+    } else {
+      set_char(x,y,c);
+      x++;
+    }
+    if (x==width) {
+      x=0;
+      y++;
+    }
+    if (y==height) {
+      x=0;
+      y=0;
+      // char* pg1=(char*)((uint32_t)screen+0xfa0);
+      // memcpy(pg1,&screen[xy_to_indx(0,1)],xy_to_indx(0,24));
+      // vga_clear();
+      // memcpy(&screen,pg1,xy_to_indx(0,25));
+    }
+  }
+  set_cursor(x,y);
+}
+
+void vga_backspace() {
+  if (x!=0) {
+      x--;
+      set_char(x,y,' ');
+      set_cursor(x,y);
+  }
+}

kernel/kernel.c

@@ -1,12 +1,12 @@
 // #include "../cpu/cpu_init.h"
-// #include "../drivers/vga.h"
+#include "../drivers/vga.h"
 // #include "../drivers/pci.h"
 // #include "../drivers/serial.h"
 // #include "../cpu/i386/ports.h"
 // #include "vfs.h"
 // #include "../fs/devfs.h"
 // #include "../fs/initrd.h"
-// #include <grub/text_fb_info.h>
+#include <grub/text_fb_info.h>
 // #include <stdlib.h>
 // #include <tasking.h>
 // #include <string.h>
@@ -138,17 +138,18 @@
 void kmain(multiboot_info_t* header) {
   // mbd=header;
   // cpu_init(mbd);
-  // text_fb_info info;
+  text_fb_info info;
   // if (header->flags&MULTIBOOT_INFO_FRAMEBUFFER_INFO&&header->framebuffer_type==2) {
   //   info.address=(char*)(((uint32_t)header->framebuffer_addr&0xFFFFFFFF)+0xC0000000);
   //   info.width=header->framebuffer_width;
   //   info.height=header->framebuffer_height;
   // } else {
-  //   info.address=(char*)0xB8000;
+    info.address=(char*)0xffff8000000B8000;
-  //   info.width=80;
+    info.width=80;
-  //   info.height=25;
+    info.height=25;
   // }
-  // vga_init(info);
+  vga_init(info);
+  vga_write_string("Hello long mode world!");
   // createTask(init);
   // for (;;) {
   //   yield();