* Implemented vga textmode

* Implemented scrolling
* Updated Makefile
* Incremented kernel version
* Added new welcome message

Author: Arun007coder

Makefile

@@ -32,6 +32,7 @@ ISOFILE=$(PROJECT).iso
 OBJECTS= 	$(SRCDIR)/boot/boot.o \
 			$(SRCDIR)/drivers/io/ports.o \
 			$(SRCDIR)/common/system.o \
+			$(SRCDIR)/drivers/video/vga_text.o \
 			$(SRCDIR)/drivers/io/serial.o \
 			$(SRCDIR)/kernel/kernel.o
 

docs/README.md

@@ -2,7 +2,7 @@
 
 A new rewrite of SectorOS_RE2.
 
-The kernel is currently v0.23.03.1ALPR
+The kernel is currently v0.23.03.2ALPR
 
 ## Build
 

docs/changelog.txt

@@ -12,4 +12,11 @@
 * Implemented serial IO
 * Fixed some typos
 * Updated Makefile
-* Deleted object files
+* Deleted object files
+
+26-03-2023: 09:44 PM IST v0.23.03.2ALPR
+* Implemented vga textmode
+* Implemented scrolling
+* Updated Makefile
+* Incremented kernel version
+* Added new welcome message

src/drivers/video/vga_text.c

@@ -0,0 +1,112 @@
+#include "vga_text.h"
+
+vga_text_t textmode;
+
+static uint16_t* text_fb = (uint16_t*)VGA_TEXT_FB;
+
+void init_text()
+{
+    textmode.height = 25;
+    textmode.width = 80;
+
+    textmode.x = 0;
+    textmode.y = 0;
+
+    textmode.fg = 0x0F;
+    textmode.bg = 0x00;
+}
+
+void move_cursor()
+{
+    uint16_t pos = textmode.y * textmode.width + textmode.x;
+    outb(0x3D4, 0x0F);
+    outb(0x3D5, (uint8_t) (pos & 0xFF));
+    outb(0x3D4, 0x0E);
+    outb(0x3D5, (uint8_t) ((pos >> 8) & 0xFF));
+}
+
+void scroll()
+{
+    uint8_t attr = (textmode.bg << 4) | (textmode.fg & 0x0F);
+    uint8_t space = 0x20 | (attr << 8);
+
+    if(textmode.y >= textmode.height)
+    {
+        int i;
+        for(i = 0*80; i < 24*80; i++)
+        {
+            text_fb[i] = text_fb[i+80];
+        }
+
+        for ( i = 24*80; i < 25*80; i++)
+        {
+            text_fb[i] = space;
+        }
+
+        textmode.y = 24;
+    }
+}
+
+void text_putc(char c)
+{
+    uint8_t attr = (textmode.bg << 4) | (textmode.fg & 0x0F);
+    uint16_t* location;
+
+    if(c == '\b' & textmode.x)
+    {
+        textmode.x--;
+    }
+    else if(c == '\t')
+    {
+        textmode.x = (textmode.x + 8) & ~(8 - 1);
+    }
+    else if(c == '\r')
+    {
+        textmode.x = 0;
+    }
+    else if(c == '\n')
+    {
+        textmode.x = 0;
+        textmode.y++;
+    }
+    else if (c >= ' ')
+    {
+        location = text_fb + (textmode.y * textmode.width + textmode.x);
+        *location = c | (attr << 8);
+        textmode.x++;
+    }
+
+    if (textmode.x >= 80)
+    {
+        textmode.x = 0;
+        textmode.y++;
+    }
+
+    scroll();
+    move_cursor();
+}
+
+void text_clear()
+{
+    uint8_t attr = (textmode.bg << 4) | (textmode.fg & 0x0F);
+    uint8_t space = 0x20 | (attr << 8);
+    for(int i = 0*80; i < 25*80; i++)
+    {
+        text_fb[i] = space;
+    }
+}
+
+void text_chcolor(uint8_t fg, uint8_t bg)
+{
+    textmode.bg = bg;
+    textmode.fg = fg;
+}
+
+void text_puts(char* str)
+{
+    while(*str)
+    {
+        text_putc(*str);
+        str++;
+    }
+}

src/include/system.h

@@ -10,7 +10,8 @@ extern uint32_t k_end;
 void panic(char* message, char* file);
 void kernel_panic(char* message);
 
-#define khalt asm("cli") asm("hlt")
+#define khalt asm("cli"); \ 
+            asm("hlt")
 
 #define KERNEL_START 0x100000
 #define KERNEL_END  k_end
@@ -23,7 +24,7 @@ void kernel_panic(char* message);
 * RELN: index of current release in the current month
 * STATUS: [PR]:Prerelease, [AL]:alpha, [NR]:Normal release
 */
-#define KERNEL_VERSION "0.23.03.1ALPR"
+#define KERNEL_VERSION "0.23.03.2ALPR"
 
 void reboot();
 

src/include/vga_text.h

@@ -0,0 +1,47 @@
+#ifndef __VGA_TEXT__
+#define __VGA_TEXT__
+
+#include "system.h"
+#include "ports.h"
+
+#define VGA_TEXT_FB 0xB8000
+
+
+#define VGA_BLACK 0
+#define VGA_BLUE 1
+#define VGA_GREEN 2
+#define VGA_CYAN 3
+#define VGA_RED 4
+#define VGA_MAGENTA 5
+#define VGA_BROWN 6
+#define VGA_LIGHT_GREY 7
+#define VGA_DARK_GREY 8
+#define VGA_LIGHT_BLUE 9
+#define VGA_LIGHT_GREEN 10
+#define VGA_LIGHT_CYAN 11
+#define VGA_LIGHT_RED 12
+#define VGA_LIGHT_MAGENTA 13
+#define VGA_LIGHT_BROWN 14
+#define VGA_WHITE 15
+
+typedef struct vga_text
+{
+    uint32_t x;
+    uint32_t y;
+
+    uint32_t height;
+    uint32_t width;
+
+    uint8_t fg;
+    uint8_t bg;
+}vga_text_t;
+
+void init_text();
+
+void text_putc(char c);
+void text_puts(char* str);
+
+void text_chcolor(uint8_t fg, uint8_t bg);
+void text_clear();
+
+#endif /*__VGA_TEXT__*/

src/kernel/kernel.c

@@ -1,18 +1,23 @@
 #include "system.h"
 #include "multiboot.h"
 #include "serial.h"
+#include "vga_text.h"
 
 void kernelmain(const multiboot_info_t* info, uint32_t multiboot_magic)
 {
-    init_serial(COM1, 0);
+    init_serial(COM1, 1);
+    init_text();
+    text_chcolor(VGA_LIGHT_GREEN, VGA_BLACK);
+    text_clear();
     if(multiboot_magic != 0x2BADB002)
     {
         serial_puts("multiboot bootloader magic is invalid\n");
         return;
     }
-    serial_puts("multiboot bootloader magic is valid...\n");
-    serial_puts("Kernel version is:");
-    serial_puts(KERNEL_VERSION);
-    serial_putc('\n');
-    reboot();
+    text_puts("Hello World!\n");
+    text_puts("multiboot bootloader magic is valid...\n");
+    text_puts("Kernel version is: ");
+    text_puts(KERNEL_VERSION);
+    text_putc('\n');
+    khalt;
 }