Minor fixes in docs

Esthetic improvements

.gitignore

@@ -1,8 +1,7 @@
 *.o
-bochslog.txt
 build/
 kernel.elf
-os.iso
 blankos.iso
-real/
+iso/
 i386-elf-7.5.0-Linux-x86_64/
+i386-elf-7.5.0-Linux-x86_64.tar.xz

README.md

@@ -1,84 +1,35 @@
-![showcase](https://github.com/user-attachments/assets/0e3208db-e585-4086-9346-c00414d98646)
+![showcase](https://github.com/user-attachments/assets/96539af5-2af9-40a1-96f4-43da1f369c36)
 
 # BlankOS
 
-Rewritten monolithic, ring 0, lower-half, single-threaded kernel for the x86 processor architecture, using GRUB (eltorito) as bootloader. Emulation was tested on Bochs and QEMU using Arch Linux 6.9.7-arch1-1, and on real hardware too.
+Rewritten monolithic, ring 0, lower-half, singletasking kernel for the x86 processor architecture, using GRUB 2 as bootloader. Emulation was tested on QEMU using Arch Linux 6.9.7-arch1-1, and on real hardware too.
 The long-term goal of this OS is to be capable of running user programs and having its own complete kernel C library so that users can write their own C programs and expand the system!
 
-## Features
-
-- Serial port driver (output & debug)
-- Framebuffer driver (output)
-- PS/2 Keyboard and PIC driver (input)
-- PIT (system clock/timer) driver
-- Working IDT, GDT, ISRs, and IRQs
-- Kernel panicking (exception handling)
-- A kernel-space shell
-- Cool color output!!
-- Some small working kernel-space programs!!
-
-### Kernel-space programs
-
-- A brainfuck interpreter
-- An arithmetic calculator
-- ROT13 and Morse cipher programs
-- Conway's Game of Life
-- And some more...
-
 ## Usage
 
-Download the latest BlankOS ISO image from the "Releases" tab, and emulate it directly using the QEMU emulator:
+Download the latest BlankOS disk image from the "Releases" tab, and start it using the QEMU emulator:
 
 ```
-qemu-system-i386 blankOS-i386-0.3.45.iso
+qemu-system-i386 blankOS-i386-0.3.55.iso
 ```
 
-Alternatively, burn the image on a USB stick and use it on a machine. (see section "Real Hardware"). *Note that the ISO images provided in the "Releases" tab are already real-hardware capable; no need to do anything except burning the image on a USB stick and running it on your machine.*
+> [!NOTE]
+> Know that the latest release is not always up-to-date with the source code. To get the most up-to-date version, instead build from source as shown below.
 
 ## Building from source
 
-### Dependencies
-
-For Debian-based distros:
-```
-sudo apt install gcc nasm make bochs
-```
-
-Then change `display-library` to `sdl2` in the `bochsrc.txt` file.
-
-For Arch-based distros:
-```
-sudo pacman -S nasm gcc make
-git clone https://aur.archlinux.org/bochs.git
-```
-
-Then follow [these](https://bbs.archlinux.org/viewtopic.php?id=178479) instructions to compile Bochs with X support. Alternatively you can use Bochs with SDL but you'll have to change the `bochsrc.txt` file accordingly.
-
-### Cross Compiler
-
-A cross-compiler is needed to build the system. More info on why [here](https://wiki.osdev.org/GCC_Cross-Compiler). In order for the build to work, you will need to download the i386-elf toolchain from [here](https://newos.org/toolchains/i386-elf-7.5.0-Linux-x86_64.tar.xz) and extract the root folder into the BlankOS root folder, or build it by youself if you're not lazy like me.
-
-Why didn't I use one sooner? Can't tell. Maybe I was too lazy. This is actually problematic because I wasn't able to use some libraries and I had to put in a bunch of weird compilation flags. It's better like this.
-
-To clone and build, do:
-
 ```
 git clone https://github.com/xamidev/blankos
+make toolchain
 make
 make run
 ```
 
-This will start a new Bochs debugger instance. To proceed with the kernel execution, you will have to type `c` in the shell spawning Bochs. Serial output will be saved under the `com1.out` file, this way you can debug the kernel by viewing its log messages. To quit, type `q`.
-You can try out QEMU too.
+The `toolchain` target will download the appropriate cross-compiling tools, and the `run` target will make a disk image for emulation or real hardware testing. *Some operations require root access. Always audit the code yourself before running anything as root!*
 
 ## Running on real hardware
 
-To run the OS on real hardware, you'll first need to have a BIOS-compatible computer. Some of the new laptops with graphical "BIOSes" only support UEFI now. So make sure to get a computer that can boot into BIOS mode, **not UEFI mode**. Then, switch the boot mode to "Legacy" in your BIOS utility.
-
-Then, use the Makefile target `real` to build a "real"-capable ISO disk image. The image will have GRUB2 installed on it, using the `grub-mkrescue` utility (make sure to install it before) which is dependent on `xorriso` (install it too).
-
-Once the ISO file is generated, you can write it on a disk using this command:
-
+The OS is now both UEFI and BIOS compatible! Burn your image file onto a USB stick:
 ```
 sudo dd bs=4M if=blankos.iso of=/dev/sdX status=progress oflag=sync
 ```
@@ -86,17 +37,9 @@ sudo dd bs=4M if=blankos.iso of=/dev/sdX status=progress oflag=sync
 Replace `sdX` with your USB drive name (you can find it by doing `sudo fdisk -l`).
 Tada! You now have a working BlankOS USB stick. Go ahead and try it out!
 
-## Post-install
+## Documentation
 
-Two documents are available to help you understand the project better. One is the User's Manual, labelled `USERS.md`, and the other one is the Developer's Manual, labelled `DEVELOPERS.md`. They are full of useful resources around Blank OS. You'll learn how to use the system and how to contribute to it.
-
-### Next Steps?
-
-Next steps for this project will be:
-
-- User programs
-- Completing the kernel libc
-- Filesystem support
+Two other documents are available to help you understand the project better. One is the User's Manual, labelled [USERS.md](docs/USERS.md), and the other one is the Developer's Manual, labelled [DEVELOPERS.md](docs/DEVELOPERS.md). They are full of useful resources around Blank OS. You'll learn how to use the system and how to contribute to it. *(The docs might not always be up-to-date)*
 
 ### Resources
 
@@ -106,7 +49,27 @@ Next steps for this project will be:
 - a great book named *Operating Systems: From 0 to 1*, by Tu, Do Hoang
 - the Intel [64 and IA-32 Architectures Software Developer Manuals](https://www.intel.com/content/www/us/en/developer/articles/technical/intel-sdm.html)
 - [Bran's Kernel Development Tutorial](http://www.osdever.net/bkerndev/index.php)
+- Ralf Brown's Interrupt List
+- the [little book about OS development](https://littleosbook.github.io/) by Erik Helin and Adam Renberg
 
-### ⚠️ Disclaimer
+### Features / Roadmap
 
-This is a hobbyist operating system kernel and it comes without any warranty whatsoever! It isn't capable of anything really. Feedback and contributions are highly appreciated!
+- [X] Booting with GRUB
+- [X] Common basic structures (IDT, GDT, ISRs, IRQs)
+- [X] Common drivers (framebuffer, keyboard, serial, timer)
+- [X] Kernel-space utilities (shell, simple programs)
+- [ ] Filesystem (FAT32 or VFS ramdisk)
+- [ ] Changing the default VGA font
+- [X] Paging/Page Frame Allocation
+- [ ] TCP/IP Network stack
+- [ ] Getting to Ring-3 (userspace)
+- [ ] Multitasking (via round robin scheduling)
+- [ ] Advanced/other drivers (video, SB16, RTC, Ethernet)
+- [X] UEFI support
+- [ ] ELF parsing
+- [ ] System calls
+- [ ] GUI
+- [ ] POSIX and ANSI specification compatibility
+
+> [!WARNING]
+> This is a hobbyist operating system, and it comes without any warranty whatsoever! See the license for more info. Feedback and contributions are highly appreciated.

bochsrc.txt

@@ -1,10 +0,0 @@
-megs:            32
-display_library: x 
-romimage:        file=/usr/share/bochs/BIOS-bochs-legacy
-vgaromimage:     file=/usr/share/bochs/VGABIOS-lgpl-latest
-ata0-master:     type=cdrom, path=os.iso, status=inserted
-boot:            cdrom
-log:             bochslog.txt
-clock:           sync=realtime, time0=local
-cpu:             count=1, ips=1000000
-com1:            enabled=1, mode=file, dev=com1.out

docs/DEVELOPERS.md

@@ -14,6 +14,19 @@ The source code is available in folder `src`. You will find subfolders correspon
 
 No system calls are available, as the OS runs in kernel-space.
 
+## Debugging the kernel (QEMU w/ GDB)
+
+```
+make debug
+```
+
+In another shell:
+
+```
+gdb kernel.elf
+(gdb) target remote localhost:1234
+```
+
 ## Making programs for the OS
 
 ### Step 1 - Making the program and the entry point

docs/USERS.md

@@ -2,6 +2,25 @@
 
 ## Getting started
 
+First, let me introduce you some features of this project.
+
+## Features
+
+- Serial port driver (output & debug)
+- Framebuffer driver (output)
+- PS/2 Keyboard and PIC driver (input)
+- PIT (system clock/timer) driver
+- Working IDT, GDT, ISRs, and IRQs
+- Kernel panicking (exception handling)
+- A kernel-space shell
+- Cool color output!!
+- Some small working kernel-space programs, such as...
+- A brainfuck interpreter
+- An arithmetic calculator
+- ROT13 and Morse cipher programs
+- Conway's Game of Life
+- And some more...
+
 ### Installation and emulation/execution
 
 Please refer to the relevant sections in the project `README.md` available in the root folder.
@@ -24,11 +43,19 @@ Triggers a kernel panic by trying to divide four by zero.
 
 #### `words`
 
-Prints ten random words using an arbitrary dictionary that you can expand in `src/programs/words.c`.
+Prints random words using an arbitrary dictionary that you can expand in `src/programs/words.c`.
+
+Options:
+- `<nothing>` will default amount of words to 10
+- `<integer>` will set the amount of words to that number 
 
 #### `primes`
 
-Computes prime numbers up to `PRIMES_MAX`, defined in `src/programs/primes.c`.
+Computes prime numbers.
+
+Options:
+- `<nothing>` will default to `PRIMES_MAX` (a million)
+- `<integer>` will compute primes up to that number
 
 #### `rainbow`
 
@@ -59,7 +86,7 @@ The classic echo command, that outputs your input.
 Outputs information about the current system (CPU and RAM).
  
 Options:
-- `nothing` will show basic info about the CPUid and lower/upper memory.
+- `<nothing>` will show basic info about the CPUid and lower/upper memory.
 - `-v` will output the CPUID, lower/upper memory, and the memory map.
 
 #### `conway`
@@ -78,3 +105,7 @@ Encode a string using the rot13 cipher.
 #### `morse`
 
 Convert a string to its morse equivalent.
+
+#### `cowsay`
+
+Makes a cow speak!

grub.cfg

@@ -1,4 +1,6 @@
 menuentry "Blank OS" {
-	multiboot /boot/kernel.elf
+	insmod all_video
+	set gfxpayload=1024x768x32
+	multiboot2 /boot/kernel.elf
 	boot
 }

iso/boot/grub/menu.lst

@@ -1,5 +0,0 @@
-default=0
-timeout=0
-
-title os
-kernel /boot/kernel.elf

link.ld

@@ -1,30 +1,31 @@
 ENTRY(loader)
 
 SECTIONS {
-  /* Address to load at; 1MB */
+  /* Address to load at; 2MB */
 
-  . = 0x00100000;
+  /*. = 2M;*/
 
-  .__mbHeader : {
-	  *(.__mbHeader)
+  .multiboot_header ALIGN(4K) : {
+  	*(.multiboot_header)
   }
-
   /* Align relevant sections at 4KB  */
 
-  .text ALIGN (0x1000) :
+  .text ALIGN (4K) :
   {
     *(.text)
     *(.rodata)
   }
 
-  .data ALIGN (0x1000) :
+  .data ALIGN (4K) :
   {
     *(.data)
   }
 
-  .bss ALIGN (0x1000) :
+  .bss ALIGN (4K) :
   {
     *(COMMON)
     *(.bss)
   }
+
+  end = .; _end = .; __end = .;
 }

makefile

@@ -1,5 +1,5 @@
 CC = i386-elf-7.5.0-Linux-x86_64/bin/i386-elf-gcc
-CFLAGS = -Wall -Wextra -Wno-builtin-declaration-mismatch -c -I src/
+CFLAGS = -ffreestanding -g -Wall -Wextra -Wno-builtin-declaration-mismatch -c -I src/
 LDFLAGS = -T link.ld -melf_i386
 AS = nasm
 ASFLAGS = -f elf
@@ -9,6 +9,8 @@ KERNEL_DIR = $(SRC_DIR)/kernel
 LIBC_DIR = $(SRC_DIR)/libc
 PROGRAMS_DIR = $(SRC_DIR)/programs
 DRIVERS_DIR = $(SRC_DIR)/drivers
+INCLUDE_DIR = include
+FONTS_DIR = $(INCLUDE_DIR)/fonts
 OBJ_DIR = build
 
 C_SOURCES = $(wildcard $(KERNEL_DIR)/*.c) $(wildcard $(LIBC_DIR)/*.c) $(wildcard $(PROGRAMS_DIR)/*.c) $(wildcard $(DRIVERS_DIR)/*.c)
@@ -16,14 +18,20 @@ ASM_SOURCES = $(wildcard $(KERNEL_DIR)/*.s) $(wildcard $(LIBC_DIR)/*.s) $(wildca
 
 OBJECTS = $(patsubst $(SRC_DIR)/%, $(OBJ_DIR)/%, $(C_SOURCES:.c=.o) $(ASM_SOURCES:.s=.o)) 
 
+TOOLCHAIN_SRC = https://newos.org/toolchains/i386-elf-7.5.0-Linux-x86_64.tar.xz
+TOOLCHAIN_FILE = i386-elf-7.5.0-Linux-x86_64.tar.xz
+
+FONT_OBJ = $(OBJ_DIR)/fonts/UniCyr_8x16.o
+FONT_SRC = $(FONTS_DIR)/UniCyr_8x16.psf
+
 all: $(OBJ_DIR) kernel.elf
 
 $(OBJ_DIR):
 	mkdir -p $(OBJ_DIR)
-	mkdir -p $(OBJ_DIR)/kernel $(OBJ_DIR)/libc $(OBJ_DIR)/programs $(OBJ_DIR)/drivers
+	mkdir -p $(OBJ_DIR)/kernel $(OBJ_DIR)/libc $(OBJ_DIR)/programs $(OBJ_DIR)/drivers $(OBJ_DIR)/fonts
 
-kernel.elf: $(OBJECTS)
-	ld $(LDFLAGS) $(OBJECTS) -o kernel.elf
+kernel.elf: $(OBJECTS) $(FONT_OBJ)
+	ld $(LDFLAGS) $(OBJECTS) $(FONT_OBJ) -o kernel.elf
 
 $(OBJ_DIR)/%.o: $(SRC_DIR)/%.c
 	$(CC) $(CFLAGS) $< -o $@
@@ -31,28 +39,28 @@ $(OBJ_DIR)/%.o: $(SRC_DIR)/%.c
 $(OBJ_DIR)/%.o: $(SRC_DIR)/%.s
 	$(AS) $(ASFLAGS) $< -o $@
 
-os.iso: kernel.elf
+$(FONT_OBJ): $(FONT_SRC) | $(OBJ_DIR)/fonts
+	objcopy -O elf32-i386 -B i386 -I binary $(FONT_SRC) $(FONT_OBJ)
+
+$(OBJ_DIR)/fonts:
+	mkdir -p $(OBJ_DIR)/fonts
+
+toolchain:
+	wget $(TOOLCHAIN_SRC)
+	tar xf $(TOOLCHAIN_FILE)
+
+iso: kernel.elf
+	mkdir -p iso/boot/grub
 	cp kernel.elf iso/boot/kernel.elf
-	genisoimage -R                              \
-							-b boot/grub/stage2_eltorito    \
-							-no-emul-boot                   \
-							-boot-load-size 4               \
-							-A os                           \
-							-input-charset utf8             \
-							-quiet                          \
-							-boot-info-table                \
-							-o os.iso                       \
-							iso
+	cp grub.cfg iso/boot/grub/grub.cfg
+	grub-mkrescue iso -o blankos.iso	
 
-real: kernel.elf
-	mkdir -p real/boot/grub
-	cp kernel.elf real/boot/kernel.elf
-	cp grub.cfg real/boot/grub/grub.cfg
-	grub-mkrescue real -o blankos.iso
+run: iso
+	qemu-system-i386 -drive file=blankos.iso,format=raw
 
-run: os.iso
-	bochs -f bochsrc.txt -q 
+debug:
+	qemu-system-i386 -s -S -drive file=blankos.iso,format=raw
 
 clean:
-	rm -rf $(OBJ_DIR) kernel.elf os.iso blankos.iso real
+	rm -rf $(OBJ_DIR) kernel.elf blankos.iso $(TOOLCHAIN_FILE)
 

src/drivers/ata.c

@@ -0,0 +1,62 @@
+// ATA PIO driver implementation
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include <stdint.h>
+#include "../kernel/io.h"
+#include "../libc/stdio.h"
+#include "ata.h"
+
+static inline uint16_t inw(uint16_t port) {
+    uint16_t result;
+    asm volatile("inw %1, %0" : "=a"(result) : "dN"(port));
+    return result;
+}
+
+static inline void outw(uint16_t port, uint16_t data) {
+    asm volatile("outw %1, %0" : : "dN"(port), "a"(data));
+}
+
+void ata_wait_bsy() {
+    while (inb(ATA_PRIMARY_IO + ATA_REG_STATUS) & ATA_SR_BSY);
+}
+
+void ata_wait_drq() {
+    while (!(inb(ATA_PRIMARY_IO + ATA_REG_STATUS) & ATA_SR_DRQ));
+}
+
+void ata_select_drive(uint8_t drive) {
+    outb(ATA_PRIMARY_IO + ATA_REG_HDDEVSEL, 0xE0 | (drive << 4));
+}
+
+void ata_read_sector(uint32_t lba, uint8_t* buffer) {
+    ata_wait_bsy();
+    ata_select_drive(0);
+
+    outb(ATA_PRIMARY_IO + ATA_REG_SECCOUNT0, 1);
+    outb(ATA_PRIMARY_IO + ATA_REG_LBA0, (uint8_t)lba);
+    outb(ATA_PRIMARY_IO + ATA_REG_LBA1, (uint8_t)(lba >> 8));
+    outb(ATA_PRIMARY_IO + ATA_REG_LBA2, (uint8_t)(lba >> 16));
+    outb(ATA_PRIMARY_IO + ATA_REG_HDDEVSEL, 0xE0 | ((lba >> 24) & 0x0F));
+
+    outb(ATA_PRIMARY_IO + ATA_REG_COMMAND, ATA_CMD_READ_PIO);
+
+    ata_wait_bsy();
+    ata_wait_drq();
+
+    for (int i = 0; i < 256; i++) {
+        ((uint16_t*)buffer)[i] = inw(ATA_PRIMARY_IO + ATA_REG_DATA);
+    }
+}
+
+// Works only w/o paging
+void test_read_sector() {
+    uint8_t buffer[512];
+    ata_read_sector(0, buffer);
+
+    for (int i = 0; i < 512; i++) {
+        if (i%25==0) puts("\n");
+	printf("%02x ", buffer[i]);
+    }
+}

src/drivers/ata.h

@@ -0,0 +1,35 @@
+// ATA PIO driver implementation header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef ATA_H
+#define ATA_H
+
+#include <stdint.h>
+
+#define ATA_PRIMARY_IO 		0x1F0
+#define ATA_PRIMARY_CTRL 	0x3F6
+#define ATA_CMD_READ_PIO	0x20
+#define ATA_CMD_WRITE_PIO 	0x30
+#define ATA_IDENTIFY 		0xEC
+
+#define ATA_REG_DATA 		0x00
+#define ATA_REG_ERROR 		0x01
+#define ATA_REG_SECCOUNT0 	0x02
+#define ATA_REG_LBA0 		0x03
+#define ATA_REG_LBA1 		0x04
+#define ATA_REG_LBA2 		0x05
+#define ATA_REG_HDDEVSEL 	0x06
+#define ATA_REG_COMMAND 	0x07
+#define ATA_REG_STATUS 		0x07
+
+#define ATA_SR_BSY 		    0x80
+#define ATA_SR_DRDY 		0x40
+#define ATA_SR_DRQ 		    0x08
+#define ATA_SR_ERR 		    0x01
+
+void ata_read_sector(uint32_t lba, uint8_t* buffer);
+void test_read_sector();
+
+#endif

src/drivers/framebuffer.c

@@ -0,0 +1,91 @@
+// Framebuffer driver
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include <stdint.h>
+#include "framebuffer.h"
+#include "serial.h"
+#include "../kernel/system.h"
+
+extern char* framebuffer;
+
+void putpixel(uint32_t* fb, int pitch, int bpp, int x, int y, uint32_t color)
+{
+	if (bpp == 32) {
+		uint32_t* pixel_addr = (uint32_t*)((uint8_t*)fb + y * pitch + x *(bpp / 8));
+		*pixel_addr = color;
+	}
+}
+
+void draw_char(unsigned short int c, int cx, int cy, uint32_t fg, uint32_t bg)
+{
+	PSF_font *font = (PSF_font*)&_binary_include_fonts_UniCyr_8x16_psf_start;
+	int bytesperline=(font->width+7)/8;
+	if (unicode != NULL) {
+		c = unicode[c];
+	}
+
+	unsigned char* glyph = (unsigned char*)&_binary_include_fonts_UniCyr_8x16_psf_start + font->headersize + (c>0&&c<font->numglyph?c:0)*font->bytesperglyph;
+
+	int offs =
+		(cy * font->height * scanline) +
+		(cx * (font->width) * sizeof(PIXEL));
+
+	unsigned int x, y;
+	int line, mask;
+
+	for (y=0; y<font->height; y++)
+	{
+		line=offs;
+		mask=1<<(font->width-1);
+
+		for (x=0; x<font->width; x++)
+		{
+			*((PIXEL*)(framebuffer + line)) = *((unsigned int*)glyph) & mask ? fg : bg;
+			mask >>= 1;
+			line += sizeof(PIXEL);
+		}
+
+		glyph += bytesperline;
+		offs += scanline;
+	}
+}
+
+void scroll()
+{
+	serial_printf(3, "Scrolling...\r");
+	uint32_t bg_color = 0x00000000;
+	PSF_font *font = (PSF_font*)&_binary_include_fonts_UniCyr_8x16_psf_start;
+	
+	int line_size = font->height * scanline;
+	int framebuffer_size = scanline * font->height * (1080/font->height);
+
+	// Erasing first line
+	for (uint32_t y=0; y<font->height; y++)
+	{
+		for (uint32_t x=0; x<scanline/sizeof(PIXEL); x++)
+		{
+			*((PIXEL*)(framebuffer + y * scanline + x * sizeof(PIXEL))) = bg_color;
+		}
+	}
+
+	// Moving all lines up by 1 line
+	for (int y=1; y<(framebuffer_size/line_size); y++)
+	{
+		void* src = framebuffer + y*line_size;
+		void* dst = framebuffer + (y-1)*line_size;
+		memmove(dst, src, line_size);
+	}
+
+	// Erasing last line
+	int last_line_start = (framebuffer_size/line_size-1) * line_size;
+	for (uint32_t y=0; y<font->height; y++)
+	{
+		for (uint32_t x=0; x<scanline/sizeof(PIXEL); x++)
+		{
+			*((PIXEL*)(framebuffer + last_line_start + y * scanline + x * sizeof(PIXEL))) = bg_color;
+		}
+	}
+}
+

src/drivers/framebuffer.h

@@ -0,0 +1,42 @@
+// Framebuffer driver header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef FRAMEBUFFER_H
+#define FRAMEBUFFER_H
+
+#include <stdint.h>
+
+extern int scanline;
+extern char _binary_include_fonts_UniCyr_8x16_psf_start;
+uint16_t* unicode;
+
+#define PIXEL uint32_t
+
+#define PSF1_FONT_MAGIC 0x0436
+
+typedef struct {
+    uint16_t magic; // Magic bytes for identification.
+    uint8_t fontMode; // PSF font mode.
+    uint8_t characterSize; // PSF character size.
+} PSF1_Header;
+
+#define PSF_FONT_MAGIC 0x864ab572
+
+typedef struct {
+    uint32_t magic;         /* magic bytes to identify PSF */
+    uint32_t version;       /* zero */
+    uint32_t headersize;    /* offset of bitmaps in file, 32 */
+    uint32_t flags;         /* 0 if there's no unicode table */
+    uint32_t numglyph;      /* number of glyphs */
+    uint32_t bytesperglyph; /* size of each glyph */
+    uint32_t height;        /* height in pixels */
+    uint32_t width;         /* width in pixels */
+} PSF_font;
+
+void putpixel(uint32_t* fb, int pitch, int bpp, int x, int y, uint32_t color); 
+void draw_char(unsigned short int c, int cx, int cy, uint32_t fg, uint32_t bg);
+void scroll();
+
+#endif

src/drivers/kb.c

@@ -1,13 +1,12 @@
+// Keyboard driver
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "../kernel/io.h"
 #include "../libc/stdio.h"
 #include "../kernel/system.h"
-
-#define KEYBOARD_BUFFER_SIZE 256
-
-#define LEFT_SHIFT_PRESSED 0x2A
-#define RIGHT_SHIFT_PRESSED 0x36
-#define LEFT_SHIFT_RELEASED 0xAA
-#define RIGHT_SHIFT_RELEASED 0xB6
+#include "kb.h"
 
 unsigned char kbdus[128] =
 {
@@ -130,6 +129,7 @@ void keyboard_handler()
 void keyboard_install()
 {
 	irq_install_handler(1, keyboard_handler);
+	printf("[keyboard] installed irq handler\n");
 }
 
 char keyboard_getchar()

src/drivers/kb.h

@@ -1,6 +1,18 @@
+// Keyboard driver header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #ifndef KB_H
 #define KB_H
 
+#define KEYBOARD_BUFFER_SIZE    256
+
+#define LEFT_SHIFT_PRESSED      0x2A
+#define RIGHT_SHIFT_PRESSED     0x36
+#define LEFT_SHIFT_RELEASED     0xAA
+#define RIGHT_SHIFT_RELEASED    0xB6
+
 char keyboard_getchar();
 
 #endif

src/drivers/rtc.c

@@ -0,0 +1,64 @@
+// Real-time clock driver implementation for better PRNG
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include <stdint.h>
+#include "rtc.h"
+#include "../kernel/io.h"
+#include "../libc/stdio.h"
+
+uint8_t rtc_read_register(uint8_t reg)
+{
+	outb(0x70, reg);
+	return inb(0x71);
+}
+
+uint8_t bcd_to_bin(uint8_t bcd)
+{
+	return ((bcd/16)*10) + (bcd%16);
+}
+
+int rtc_is_updating()
+{
+	outb(0x70, 0x0A);
+	return (inb(0x71) & 0x80);
+}
+
+void rtc_read_time(rtc_time_t *time)
+{
+	while (rtc_is_updating());
+
+	time->seconds = rtc_read_register(0x00);
+	time->minutes = rtc_read_register(0x02);
+	time->hours = rtc_read_register(0x04);
+	time->day = rtc_read_register(0x06);
+	time->month = rtc_read_register(0x07);
+	time->year = rtc_read_register(0x08);
+
+	outb(0x70, 0x0B);
+	uint8_t registerB = inb(0x71);
+
+	if (!(registerB & 0x04))
+	{
+		time->seconds = bcd_to_bin(time->seconds);
+		time->minutes = bcd_to_bin(time->minutes);
+		time->hours = bcd_to_bin(time->hours);
+		time->day = bcd_to_bin(time->day);
+		time->month = bcd_to_bin(time->month);
+		time->year = bcd_to_bin(time->year);
+	}
+}
+
+void print_time(const rtc_time_t *time)
+{
+	printf("%02d/%02d/%02d %02d:%02d:%02d\n", time->day, time->month, time->year, time->hours, time->minutes, time->seconds);
+}
+
+long time_seed()
+{
+	rtc_time_t* time = {0};
+	rtc_read_time(time);
+	
+	return time->day + time->month + time->year + time->hours + time->minutes + time->seconds;	
+}

src/drivers/rtc.h

@@ -0,0 +1,23 @@
+// Real-time clock driver implementation header for better PRNG
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef RTC_H
+#define RTC_H
+
+typedef struct
+{
+	uint8_t seconds;
+	uint8_t minutes;
+	uint8_t hours;
+	uint8_t day;
+	uint8_t month;
+	uint8_t year;
+} rtc_time_t;
+
+void rtc_read_time(rtc_time_t *time);
+long time_seed();
+void print_time(const rtc_time_t *time);
+
+#endif

src/drivers/serial.c

@@ -1,3 +1,8 @@
+// Serial I/O driver
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "../kernel/io.h"
 #include "serial.h"
 #include "../libc/stdio.h"
@@ -20,6 +25,7 @@ int init_serial()
   }
 
   outb(PORT+4, 0x0F);
+  puts("[serial] initialized i/o on port COM1\n");
   return 0;
 }
 
@@ -276,6 +282,5 @@ void serial_printf(int errlevel, const char* fmt, ...)
     }
     fmt++;
   }
-  serial_puts("\n");
+  serial_puts("\r\n");
 }
-

src/drivers/serial.h

@@ -1,5 +1,10 @@
-#ifndef INCLUDE_SERIAL_H
-#define INCLUDE_SERIAL_H
+// Serial I/O driver header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef SERIAL_H
+#define SERIAL_H
 
 #define PORT 0x3f8 //COM1
 
@@ -9,4 +14,5 @@ void write_serial(const char a);
 void serial_puts(const char* str);
 void log(const char* str, const int errlevel);
 void serial_printf(int errlevel, const char* fmt, ...);
+
 #endif

src/drivers/timer.c

@@ -1,3 +1,8 @@
+// Programmable Interval Timer channel 0 driver
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "../kernel/system.h"
 #include "../libc/stdio.h"
 
@@ -6,11 +11,18 @@ volatile unsigned long global_ticks = 0;
 void timer_handler()
 {
 	global_ticks++;
+	if (global_ticks % 20 == 0)
+	{
+		draw_cursor(white);
+	} else if (global_ticks % 20 == 10) {
+		erase_cursor();
+	}
 }
 
 void timer_install()
 {
 	irq_install_handler(0, timer_handler);
+	printf("[timer] initialized, starting g_ticks...\n");
 }
 
 void delay(int ticks)

src/kernel/gdt.c

@@ -1,20 +1,10 @@
+// Global descriptor table setup
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "gdt.h"
-
-struct gdt_entry
-{
-	unsigned short limit_low;
-	unsigned short base_low;
-	unsigned char base_middle;
-	unsigned char access;
-	unsigned char granularity;
-	unsigned char base_high;
-} __attribute__((packed));
-
-struct gdt_ptr
-{
-	unsigned short limit;
-	unsigned int base;
-} __attribute__((packed));
+#include "../libc/stdio.h"
 
 struct gdt_entry gdt[3];
 struct gdt_ptr gp;
@@ -41,8 +31,14 @@ void gdt_install()
 
 	gdt_set_gate(0, 0, 0, 0, 0);
 	
+	// Ring 0 code + data
 	gdt_set_gate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF);
 	gdt_set_gate(2, 0, 0xFFFFFFFF, 0x92, 0xCF);
 
+	// Ring 3
+	gdt_set_gate(3, 0, 0xFFFFFFFF, 0xFA, 0xCF);
+	gdt_set_gate(4, 0, 0xFFFFFFFF, 0xF2, 0xCF);
+
 	gdt_flush();
+	printf("[kernel] GDT gates set (ring 0 and 3), gdt=0x%x\n", &gdt);
 }

src/kernel/gdt.h

@@ -1,8 +1,28 @@
+// Global descriptor table setup header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #ifndef GDT_H
 #define GDT_H
 
-void gdt_set_gate(int num, unsigned long base, unsigned long limit, unsigned char access, unsigned char gran);
+struct gdt_entry
+{
+	unsigned short limit_low;
+	unsigned short base_low;
+	unsigned char base_middle;
+	unsigned char access;
+	unsigned char granularity;
+	unsigned char base_high;
+} __attribute__((packed));
 
+struct gdt_ptr
+{
+	unsigned short limit;
+	unsigned int base;
+} __attribute__((packed));
+
+void gdt_set_gate(int num, unsigned long base, unsigned long limit, unsigned char access, unsigned char gran);
 void gdt_install();
 
 #endif

src/kernel/idt.c

@@ -1,20 +1,11 @@
+// Interrupt descriptor table setup
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "idt.h"
 #include "system.h"
-
-struct idt_entry
-{
-	unsigned short base_lo;
-	unsigned short sel;
-	unsigned char always0;
-	unsigned char flags;
-	unsigned short base_hi;
-} __attribute__((packed));
-
-struct idt_ptr
-{
-	unsigned short limit;
-	unsigned int base;
-} __attribute__((packed));
+#include "../libc/stdio.h"
 
 struct idt_entry idt[256];
 struct idt_ptr idtp;
@@ -39,4 +30,5 @@ void idt_install()
 	memset(&idt, 0, sizeof(struct idt_entry)*256);
 
 	idt_load();
+	printf("[kernel] loaded IDT at idt=0x%x\n", &idt);
 }

src/kernel/idt.h

@@ -1,8 +1,27 @@
+// Interrupt descriptor table setup header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #ifndef IDT_H
 #define IDT_H
 
-void idt_set_gate(unsigned char num, unsigned long base, unsigned short sel, unsigned char flags);
+struct idt_entry
+{
+	unsigned short base_lo;
+	unsigned short sel;
+	unsigned char always0;
+	unsigned char flags;
+	unsigned short base_hi;
+} __attribute__((packed));
 
+struct idt_ptr
+{
+	unsigned short limit;
+	unsigned int base;
+} __attribute__((packed));
+
+void idt_set_gate(unsigned char num, unsigned long base, unsigned short sel, unsigned char flags);
 void idt_install();
 
 #endif

src/kernel/io.h

@@ -1,7 +1,12 @@
-#ifndef INCLUDE_IO_H
-#define INCLUDE_IO_H
+// Raw CPU port I/O kernel module header 
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
 
-#include "../libc/stdint.h"
+#ifndef IO_H
+#define IO_H
+
+#include <stdint.h>
 
 void outb(unsigned short port, unsigned char data);
 unsigned char inb(unsigned short port);

src/kernel/io.s

@@ -1,3 +1,8 @@
+; Raw CPU port I/O kernel module
+; Author: xamidev
+; Licensed under the Unlicense. See the repo below.
+; https://github.com/xamidev/blankos
+
 global outb
 
 outb:

src/kernel/irq.c

@@ -1,6 +1,12 @@
+// Interrupt Requests setup
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "system.h"
 #include "io.h"
 #include "idt.h"
+#include "../libc/stdio.h"
 
 extern void irq0();
 extern void irq1();
@@ -69,6 +75,7 @@ void irq_install()
 	idt_set_gate(45, (unsigned)irq13, 0x08, 0x8E);
 	idt_set_gate(46, (unsigned)irq14, 0x08, 0x8E);
 	idt_set_gate(47, (unsigned)irq15, 0x08, 0x8E);
+	printf("[kernel] installed irq 0-15\n");
 }
 
 void irq_handler(struct regs *r)

src/kernel/isr.c

@@ -1,3 +1,8 @@
+// Interrupt service routines setup 
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "system.h"
 #include "../libc/stdio.h"
 #include "idt.h"
@@ -37,7 +42,6 @@ extern void isr31();
 
 void isr_install()
 {
-
 	idt_set_gate(0, (unsigned)isr0, 0x08, 0x8E);
 	idt_set_gate(1, (unsigned)isr1, 0x08, 0x8E);
 	idt_set_gate(2, (unsigned)isr2, 0x08, 0x8E);
@@ -70,6 +74,7 @@ void isr_install()
 	idt_set_gate(29, (unsigned)isr29, 0x08, 0x8E);
 	idt_set_gate(30, (unsigned)isr30, 0x08, 0x8E);
 	idt_set_gate(31, (unsigned)isr31, 0x08, 0x8E);
+	printf("[kernel] set ISRs 0-31\n");
 }
 
 char *exception_messages[] =
@@ -115,4 +120,3 @@ void fault_handler(struct regs *r)
 		for (;;);
 	}
 }
-

src/kernel/kheap.c

@@ -0,0 +1,46 @@
+// Kernel heap management
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include "kheap.h"
+#include <stdint.h>
+
+extern uint32_t end;
+uint32_t placement_address = (uint32_t)&end;
+
+uint32_t kmalloc_int(uint32_t sz, int align, uint32_t *phys)
+{
+	if (align == 1 && (placement_address & 0x00000FFF))
+	{
+		placement_address &= 0xFFFFF000;
+		placement_address += 0x1000;
+	}
+	if (phys)
+	{
+		*phys = placement_address;
+	}
+	uint32_t tmp = placement_address;
+	placement_address += sz;
+	return tmp;
+}
+
+uint32_t kmalloc_a(uint32_t sz)
+{
+	return kmalloc_int(sz, 1, 0);
+}
+
+uint32_t kmalloc_p(uint32_t sz, uint32_t *phys)
+{
+	return kmalloc_int(sz, 0, phys);
+}
+
+uint32_t kmalloc_ap(uint32_t sz, uint32_t *phys)
+{
+	return kmalloc_int(sz, 1, phys);
+}
+
+uint32_t kmalloc(uint32_t sz)
+{
+	return kmalloc_int(sz, 0, 0);
+}

src/kernel/kheap.h

@@ -0,0 +1,16 @@
+// Kernel heap management header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef KHEAP_H
+#define KHEAP_H
+
+#include <stdint.h>
+
+uint32_t kmalloc_a(uint32_t sz);
+uint32_t kmalloc_p(uint32_t sz, uint32_t *phys);
+uint32_t kmalloc_ap(uint32_t sz, uint32_t *phys);
+uint32_t kmalloc(uint32_t sz);
+
+#endif

src/kernel/kmain.c

@@ -1,45 +1,74 @@
+// Kernel entry point
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "../libc/stdio.h"
 #include "../drivers/serial.h"
 #include "gdt.h"
 #include "idt.h"
 #include "system.h"
-//#include <stdarg.h>
+#include "paging.h"
+#include "../drivers/ata.h"
+#include <stdint.h>
+#include "../drivers/framebuffer.h"
+#include "kmain.h"
 
-char* ascii_title =
-"\n"
-"   oooooooooo o888                         oooo          ooooooo    oooooooo8\n"
-"   888    888 888   ooooooo   oo oooooo    888  ooooo o888   888o 888        \n"
-"   888oooo88  888   ooooo888   888   888   888o888    888     888  888oooooo \n"
-"   888    888 888 888    888   888   888   8888 88o   888o   o888         888\n"
-"   o888ooo888 o888o 88ooo88 8o o888o o888o o888o o888o   88ooo88   o88oooo888\n\n"
-"   --------------------------------- v0.3.55 --------------------------------\n\n";
-
-unsigned int g_multiboot_info_address;
-
-void kmain(unsigned int multiboot_info_address)
+void kmain(multiboot2_info *mb_info)
 {
-  g_multiboot_info_address = multiboot_info_address;
+	multiboot2_tag_framebuffer *fb_info = NULL;
+
+    uint8_t *tags = mb_info->tags;
+    while (1) {
+        uint32_t tag_type = *((uint32_t*) tags);
+        uint32_t tag_size = *((uint32_t*) (tags + 4));
+
+        if (tag_type == 0) break;
+        if (tag_type == 8) {
+            fb_info = (multiboot2_tag_framebuffer*) tags;
+        }
+
+        tags += ((tag_size + 7) & ~7);
+    }
+
+    serial_printf(3, "Framebuffer Address: 0x%x", fb_info->framebuffer_addr);
+	serial_printf(3, "Framebuffer Width: %u", fb_info->framebuffer_width);
+	serial_printf(3, "Framebuffer Height: %u", fb_info->framebuffer_height);
+	serial_printf(3, "Framebuffer Pitch: %u", fb_info->framebuffer_pitch);
+	serial_printf(3, "Framebuffer BPP: %u", fb_info->framebuffer_bpp);
+
+    if (fb_info) {
+        framebuffer = (uint32_t *)(uintptr_t) fb_info->framebuffer_addr;
+
+        uint32_t width = fb_info->framebuffer_width;
+        uint32_t height = fb_info->framebuffer_height;
+        uint32_t bpp = fb_info->framebuffer_bpp;
+
+        //8x16 font, not padded 
+        VGA_WIDTH = width/8;
+        VGA_HEIGHT = height/16;
+        serial_printf(3, "VGA_WIDTH=%d, VGA_HEIGHT=%d", VGA_WIDTH, VGA_HEIGHT);
+        scanline = width * (bpp/8);	
+    }
+
+    printf("[kernel] multiboot2 info at 0x%x, size=%u\n", mb_info, mb_info->total_size);
+    printf("[kernel] framebuffer discovered at 0x%x\n", fb_info->framebuffer_addr);
+    printf("[kernel] fb0: width=%u, height=%u, pitch=%u, bpp=%u\n", fb_info->framebuffer_width, fb_info->framebuffer_height, fb_info->framebuffer_pitch, fb_info->framebuffer_bpp);
 
     init_serial();
-  log("serial connection established\n", 3);
     gdt_install();
-  log("initialized GDT entries\n", 2);
     idt_install();
-  log("initialized IDT\n", 2);
     isr_install();
-  log("initialized ISRs\n", 2);
     irq_install();
     __asm__ __volatile__("sti");
-  log("initialized IRQs\n", 2),
  
-  clear();
-  colorputs(ascii_title, 10);
-  colorputs("   by @xamidev - star the repo for a cookie!\n\n", 14);
+    //init_paging();
+    //test_read_sector();
+    //uint32_t *ptr = (uint32_t*)0xA0000000;
+    //uint32_t do_page_fault = *ptr;
 
     timer_install();
-  serial_printf(2, "%d\tinitialized timer handler", global_ticks); 
     keyboard_install();
-  serial_printf(2, "%d\tinitialized keyboard handler", global_ticks); 
+    printf("[kernel] spawning shell...\n"); 
     shell_install();
-  serial_printf(2, "%d\tstarted system shell", global_ticks); 
 }

src/kernel/kmain.h

@@ -0,0 +1,36 @@
+// Kernel entry point header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef KMAIN_H
+#define KMAIN_H
+
+typedef struct {
+    uint32_t type;
+    uint32_t size;
+    uint64_t framebuffer_addr;
+    uint32_t framebuffer_pitch;
+    uint32_t framebuffer_width;
+    uint32_t framebuffer_height;
+    uint8_t framebuffer_bpp;
+    uint8_t framebuffer_type;
+    uint16_t reserved;
+} multiboot2_tag_framebuffer;
+
+typedef struct {
+    uint32_t total_size;
+    uint32_t reserved;
+    uint8_t tags[0];
+} multiboot2_info;
+
+unsigned int g_multiboot_info_address;
+
+uint32_t* framebuffer;
+int scanline;
+
+// in characters, not pixels
+uint32_t VGA_WIDTH;
+uint32_t VGA_HEIGHT;
+
+#endif

src/kernel/loader.s

@@ -1,25 +1,54 @@
+; Kernel loader assembly stub and multiboot2 header
+; Author: xamidev
+; Licensed under the Unlicense. See the repo below.
+; https://github.com/xamidev/blankos
+
 global loader
 
-section .__mbHeader
+section .multiboot_header
 
-align 0x4
-section .text:
+align 8
 
-MAGIC_NUMBER      equ 0x1BADB002   ; multiboot magic 
-FLAGS             equ 0x0 
-CHECKSUM          equ -MAGIC_NUMBER
-KERNEL_STACK_SIZE equ 4096
+; ASM macros
 
-  dd MAGIC_NUMBER
+MAGIC_NUMBER      equ 0xe85250d6  	; multiboot2 magic 
+FLAGS             equ 0x0	  		; 32-bit protected mode for i386
+HEADER_LEN	  	  equ 44 	  		; Tags=2+2+4+4+4+4+2+2+4=28
+CHECKSUM          equ -(MAGIC_NUMBER + FLAGS + HEADER_LEN)
+
+; Multiboot 2 header, according to specification (16bytes)
+
+  dd MAGIC_NUMBER		; dd = 4 bytes = 32bits = u32
   dd FLAGS			
+  dd HEADER_LEN
   dd CHECKSUM
 
+; Tags? (28bytes)
+
+; Tag 1 : set graphics mode (only recommended, can be overriden by GRUB)
+
+  dw 5			; 2
+  dw 0			; 2
+  dd 20			; 4
+  dd 1920		; 4
+  dd 1080		; 4
+  dd 32			; 4
+
+; End of tags
+
+  dw 0			; 2
+  ;dw 0			; 2
+  dd 8			; 4
+
+; End of Multiboot 2 header
+
+section .text:
+
+KERNEL_STACK_SIZE equ 4096
 extern kmain
 
 loader:
   	cli
-  ; mov eax, 0xCAFEBABE
-  ; push dword 42
   	push ebx
   	call kmain
 
@@ -49,225 +78,55 @@ idt_load:
 	lidt [idtp]
 	ret
 
-global isr0
-global isr1
-global isr2
-global isr3
-global isr4
-global isr5
-global isr6
-global isr7
-global isr8
-global isr9
-global isr10
-global isr11
-global isr12
-global isr13
-global isr14
-global isr15
-global isr16
-global isr17
-global isr18
-global isr19
-global isr20
-global isr21
-global isr22
-global isr23
-global isr24
-global isr25
-global isr26
-global isr27
-global isr28
-global isr29
-global isr30
-global isr31
-
-; Interrupt service routine exceptions
-isr0:
+%macro ISR_NOERRCODE 1
+	global isr%1
+	isr%1:
 		cli
 		push byte 0
-	push byte 0
+		push byte %1
 		jmp isr_common_stub
+%endmacro
 
-isr1:
+%macro ISR_ERRCODE 1
+	global isr%1
+	isr%1:
 		cli
-	push byte 0
-	push byte 1
+		push byte %1
 		jmp isr_common_stub
+%endmacro
 
-isr2:
-	cli
-	push byte 0
-	push byte 2
-	jmp isr_common_stub
-
-isr3:
-	cli
-	push byte 0
-	push byte 3
-	jmp isr_common_stub
-
-isr4:
-	cli
-	push byte 0
-	push byte 4
-	jmp isr_common_stub
-
-isr5:
-	cli
-	push byte 0
-	push byte 5
-	jmp isr_common_stub
-
-isr6:
-	cli
-	push byte 0
-	push byte 6
-	jmp isr_common_stub
-
-isr7:
-	cli
-	push byte 0
-	push byte 7
-	jmp isr_common_stub
-
-isr8:
-	cli
-	push byte 8
-	jmp isr_common_stub
-
-isr9:
-	cli
-	push byte 0
-	push byte 9
-	jmp isr_common_stub
-
-isr10:
-	cli
-	push byte 10
-	jmp isr_common_stub
-
-isr11:
-	cli
-	push byte 11
-	jmp isr_common_stub
-
-isr12:
-	cli
-	push byte 12
-	jmp isr_common_stub
-
-isr13:
-	cli
-	push byte 13
-	jmp isr_common_stub
-
-isr14:
-	cli
-	push byte 14
-	jmp isr_common_stub
-
-isr15:
-	cli
-	push byte 0
-	push byte 15
-	jmp isr_common_stub
-
-isr16:
-	cli
-	push byte 0
-	push byte 16
-	jmp isr_common_stub
-
-isr17:
-	cli
-	push byte 0
-	push byte 17
-	jmp isr_common_stub
-
-isr18:
-	cli
-	push byte 0
-	push byte 18
-	jmp isr_common_stub
-
-isr19:
-	cli
-	push byte 0
-	push byte 19
-	jmp isr_common_stub
-
-isr20:
-	cli
-	push byte 0
-	push byte 20
-	jmp isr_common_stub
-
-isr21:
-	cli
-	push byte 0
-	push byte 21
-	jmp isr_common_stub
-
-isr22:
-	cli
-	push byte 0
-	push byte 22
-	jmp isr_common_stub
-
-isr23:
-	cli
-	push byte 0
-	push byte 23
-	jmp isr_common_stub
-
-isr24:
-	cli
-	push byte 0
-	push byte 24
-	jmp isr_common_stub
-
-isr25:
-	cli
-	push byte 0
-	push byte 25
-	jmp isr_common_stub
-
-isr26:
-	cli
-	push byte 0
-	push byte 26
-	jmp isr_common_stub
-
-isr27:
-	cli
-	push byte 0
-	push byte 27
-	jmp isr_common_stub
-
-isr28:
-	cli
-	push byte 0
-	push byte 28
-	jmp isr_common_stub
-
-isr29:
-	cli
-	push byte 0
-	push byte 29
-	jmp isr_common_stub
-
-isr30:
-	cli
-	push byte 0
-	push byte 30
-	jmp isr_common_stub
-
-isr31:
-	cli
-	push byte 0
-	push byte 31
-	jmp isr_common_stub
+ISR_NOERRCODE 0
+ISR_NOERRCODE 1
+ISR_NOERRCODE 2
+ISR_NOERRCODE 3
+ISR_NOERRCODE 4
+ISR_NOERRCODE 5
+ISR_NOERRCODE 6
+ISR_NOERRCODE 7
+ISR_ERRCODE 8
+ISR_NOERRCODE 9
+ISR_ERRCODE 10
+ISR_ERRCODE 11
+ISR_ERRCODE 12
+ISR_ERRCODE 13
+ISR_ERRCODE 14
+ISR_NOERRCODE 15
+ISR_NOERRCODE 16
+ISR_NOERRCODE 17
+ISR_NOERRCODE 18
+ISR_NOERRCODE 19
+ISR_NOERRCODE 20
+ISR_NOERRCODE 21
+ISR_NOERRCODE 22
+ISR_NOERRCODE 23
+ISR_NOERRCODE 24
+ISR_NOERRCODE 25
+ISR_NOERRCODE 26
+ISR_NOERRCODE 27
+ISR_NOERRCODE 28
+ISR_NOERRCODE 29
+ISR_NOERRCODE 30
+ISR_NOERRCODE 31
 
 extern fault_handler
 
@@ -295,118 +154,31 @@ isr_common_stub:
 	add esp, 8
 	iret
 
-global irq0
-global irq1
-global irq2
-global irq3
-global irq4
-global irq5
-global irq6
-global irq7
-global irq8
-global irq9
-global irq10
-global irq11
-global irq12
-global irq13
-global irq14
-global irq15
-
-irq0:
+%macro IRQ 2
+	global irq%1
+	irq%1:
 		cli
 		push byte 0
-	push byte 32
+		push byte %2
 		jmp irq_common_stub
+%endmacro
 
-irq1:
-	cli
-	push byte 0
-	push byte 33
-	jmp irq_common_stub
-
-irq2:
-	cli
-	push byte 0
-	push byte 34
-	jmp irq_common_stub
-
-irq3:
-	cli
-	push byte 0
-	push byte 35
-	jmp irq_common_stub
-
-irq4:
-	cli
-	push byte 0
-	push byte 36
-	jmp irq_common_stub
-
-irq5:
-	cli
-	push byte 0
-	push byte 37
-	jmp irq_common_stub
-
-irq6:
-	cli
-	push byte 0
-	push byte 38
-	jmp irq_common_stub
-
-irq7:
-	cli
-	push byte 0
-	push byte 39
-	jmp irq_common_stub
-
-irq8:
-	cli
-	push byte 0
-	push byte 40
-	jmp irq_common_stub
-
-irq9:
-	cli
-	push byte 0
-	push byte 41
-	jmp irq_common_stub
-
-irq10:
-	cli
-	push byte 0
-	push byte 42
-	jmp irq_common_stub
-
-irq11:
-	cli
-	push byte 0
-	push byte 43
-	jmp irq_common_stub
-
-irq12:
-	cli
-	push byte 0
-	push byte 44
-	jmp irq_common_stub
-
-irq13:
-	cli
-	push byte 0
-	push byte 45
-	jmp irq_common_stub
-
-irq14:
-	cli
-	push byte 0
-	push byte 46
-	jmp irq_common_stub
-
-irq15:
-	cli
-	push byte 0
-	push byte 47
-	jmp irq_common_stub
+IRQ	0,	32
+IRQ	1,	33
+IRQ	2,	34
+IRQ	3,	35
+IRQ	4,	36
+IRQ	5,	37
+IRQ	6,	38
+IRQ	7,	39
+IRQ	8,	40
+IRQ	9,	41
+IRQ	10,	42
+IRQ	11,	43
+IRQ	12,	44
+IRQ	13,	45
+IRQ	14,	46
+IRQ	15,	47
 
 extern irq_handler
 

src/kernel/paging.c

@@ -0,0 +1,151 @@
+// Paging kernel module
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include <stdint.h>
+#include "paging.h"
+#include "../libc/stdio.h"
+#include "system.h"
+#include "kheap.h"
+
+uint32_t *frames;
+uint32_t nframes;
+
+extern uint32_t placement_address;
+
+static void set_frame(uint32_t frame_addr)
+{
+	uint32_t frame = frame_addr/0x1000;
+	uint32_t idx = INDEX_FROM_BIT(frame);
+	uint32_t off = OFFSET_FROM_BIT(frame);
+	frames[idx] |= (0x1 << off);
+}
+
+static void clear_frame(uint32_t frame_addr)
+{
+	uint32_t frame = frame_addr/0x1000;
+	uint32_t idx = INDEX_FROM_BIT(frame);
+	uint32_t off = OFFSET_FROM_BIT(frame);
+	frames[idx] &= ~(0x1 << off);
+}
+
+/*
+static uint32_t test_frame(uint32_t frame_addr)
+{
+   	uint32_t frame = frame_addr/0x1000;
+   	uint32_t idx = INDEX_FROM_BIT(frame);
+   	uint32_t off = OFFSET_FROM_BIT(frame);
+   	return (frames[idx] & (0x1 << off));
+}
+*/
+
+static uint32_t first_frame()
+{
+	uint32_t i, j;
+	for (i=0; i<INDEX_FROM_BIT(nframes); i++)
+	{
+		if (frames[i] != 0xFFFFFFFF)
+		{
+			for (j=0; j<32; j++)
+			{
+				uint32_t toTest = 0x1 << j;
+				if (!(frames[i]&toTest))
+				{
+					return i*4*8+j;
+				}
+			}
+		}
+	}
+	return 0;
+}
+
+void alloc_frame(page_t *page, int is_kernel, int is_writeable)
+{
+	if (page->frame != 0)
+	{
+		return;
+	} else {
+		uint32_t idx = first_frame();
+		if (idx == (uint32_t)-1)
+		{
+			panic();
+		}
+		set_frame(idx*0x1000);
+		page->present = 1;
+		page->rw = (is_writeable)?1:0;
+		page->user = (is_kernel)?0:1;
+		page->frame = idx;
+	}
+}
+
+void free_frame(page_t *page)
+{
+	uint32_t frame;
+	if (!(frame=page->frame))
+	{
+		return;
+	} else {
+		clear_frame(frame);
+		page->frame = 0x0;
+	}
+}
+
+void init_paging()
+{
+	uint32_t mem_end_page = 0x10000000;
+	nframes = mem_end_page / 0x1000;
+	frames = (uint32_t*)kmalloc(INDEX_FROM_BIT(nframes));
+	memset(frames, 0, INDEX_FROM_BIT(nframes));
+
+	page_directory_t* kernel_directory = (page_directory_t*)kmalloc_a(sizeof(page_directory_t));
+	memset(kernel_directory, 0, sizeof(page_directory_t));
+	//page_directory_t* current_directory = kernel_directory;
+
+	unsigned int i = 0;
+	while (i < placement_address)
+	{
+		alloc_frame(get_page(i, 1, kernel_directory), 0, 0);
+		i += 0x1000;
+	}
+
+	irq_install_handler(14, page_fault);
+
+	switch_page_directory(kernel_directory);	
+}
+
+void switch_page_directory(page_directory_t *dir)
+{
+	//page_directory_t* current_directory = dir;
+	asm volatile("mov %0, %%cr3":: "r"(&dir->tablesPhysical));
+	uint32_t cr0;
+	asm volatile("mov %%cr0, %0": "=r"(cr0));
+	cr0 |= 0x80000000;
+	asm volatile("mov %0, %%cr0":: "r"(cr0));
+}
+
+page_t *get_page(uint32_t address, int make, page_directory_t *dir)
+{
+	address /= 0x1000;
+	uint32_t table_idx = address / 1024;
+	if (dir->tables[table_idx])
+	{
+		return &dir->tables[table_idx]->pages[address%1024];
+	} else if (make)
+	{
+		uint32_t tmp;
+		dir->tables[table_idx] = (page_table_t*)kmalloc_ap(sizeof(page_table_t), &tmp);
+		memset(dir->tables[table_idx], 0, 0x1000);
+		dir->tablesPhysical[table_idx] = tmp | 0x7;
+		return &dir->tables[table_idx]->pages[address%1024];
+	} else {
+		return 0;
+	}
+	return 0;
+}
+
+void page_fault()
+{
+	puts("Page fault");
+	panic();
+}

src/kernel/paging.h

@@ -0,0 +1,43 @@
+// Paging kernel module header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef PAGING_H
+#define PAGING_H
+
+#include "system.h"
+#include <stdint.h>
+
+#define INDEX_FROM_BIT(a) (a/(8*4))
+#define OFFSET_FROM_BIT(a) (a%(8*4))
+
+typedef struct
+{
+	uint32_t present	: 1;
+	uint32_t rw			: 1;
+	uint32_t user		: 1;
+	uint32_t accessed	: 1;
+	uint32_t dirty		: 1;
+	uint32_t unused		: 7;
+	uint32_t frame		: 20;
+} page_t;
+
+typedef struct
+{
+	page_t pages[1024];
+} page_table_t;
+
+typedef struct
+{
+	page_table_t *tables[1024];
+	uint32_t tablesPhysical[1024];
+	uint32_t physicalAsddr;
+} page_directory_t;
+
+void init_paging();
+void switch_page_directory(page_directory_t *new);
+page_t *get_page(uint32_t address, int make, page_directory_t *dir);
+void page_fault();
+
+#endif

src/kernel/shell.c

@@ -1,13 +1,46 @@
+// Basic shell and commands kernel module
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "system.h"
 #include "../libc/stdio.h"
 #include "../libc/string.h"
 #include "../programs/programs.h"
-#include "../libc/stdint.h"
+#include "../libc/crypto.h"
+#include <stdint.h>
+#include "../drivers/rtc.h"
 
 #define BUFFER_SIZE 256
 #define MAX_COMMANDS 16
 #define MAX_ARGS     64
 
+// Splash screen: esthetic stuff.
+
+char* motd[] = 
+{
+	"Now in 2D!",
+	"Supercalifragilisticexpialidocious!",
+	"Tylko jedno w glowie mam!",
+};
+int motd_size = sizeof(motd)/sizeof(motd[0]);
+
+void splash()
+{ 
+	int random = randint(time_seed());
+	char* motd_pick = motd[random%motd_size];
+	cowsay(motd_pick, red, black);
+	colorputs("        blankOS 0.3.86-alpha", red, black);
+	puts("\n");
+	
+
+	puts("        Time: ");
+	rtc_time_t time;
+	rtc_read_time(&time);
+	print_time(&time);
+	puts("\n");
+}
+
 typedef void (*command_func_t)(int argc, char *argv[]);
 
 typedef struct
@@ -54,6 +87,8 @@ int parse_input(char* input, char* argv[], int max_args)
 
 void shell_install()
 {
+  splash();	
+  
   register_command("help", program_help);
   register_command("panic", program_panic);
   register_command("words", program_words);
@@ -68,12 +103,19 @@ void shell_install()
   register_command("conway", program_conway);
   register_command("rot13", program_rot13);
   register_command("morse", program_morse);
+  register_command("cowsay", program_cowsay);
 
   for (;;)
   {
     char input_buffer[BUFFER_SIZE];
     char* argv[MAX_ARGS];
-    colorputs("blankos> ", 9);
+
+    // Prompt
+    colorputs("root", blue, black);
+    colorputs("@", white, black);
+    colorputs("blankos", green, black);
+    colorputs("~$ ", white, black);
+
     get_input(input_buffer, BUFFER_SIZE);
     puts("\n");
     

src/kernel/sysinfo.c

@@ -1,3 +1,8 @@
+// System information kernel module
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "../libc/stdio.h"
 #include "../libc/string.h"
 

src/kernel/sysinfo.h

@@ -1,3 +1,8 @@
+// System information kernel module header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #ifndef SYSINFO_H
 #define SYSINFO_H
 

src/kernel/system.c

@@ -1,4 +1,10 @@
+// System utilities and routines kernel module
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "system.h"
+#include <stdint.h>
 
 void *memset(void *dest, char val, size_t count)
 {
@@ -6,3 +12,29 @@ void *memset(void *dest, char val, size_t count)
 	for(; count != 0; count--) *temp++ = val;
 	return dest;
 }
+
+void *memmove(void* dest, const void* src, size_t n)
+{
+	unsigned char* d = (unsigned char*)dest;
+	const unsigned char* s = (const unsigned char*)src;
+
+	if (d < s)
+	{
+		for (size_t i=0; i<n; i++)
+		{
+			d[i] = s[i];
+		}
+	} else {
+		for (size_t i=n; i>0; i--)
+		{
+			d[i-1] = s[i-1];
+		}
+	}
+
+	return dest;
+}
+
+void panic()
+{
+	for (;;);	
+}

src/kernel/system.h

@@ -1,9 +1,18 @@
+// System utilities and routines kernel module header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #ifndef SYSTEM_H
 #define SYSTEM_H
 
+#include <stdint.h>
+
 typedef int size_t;
+#define NULL ((void*)0)
 
 void *memset(void *dest, char val, size_t count);
+void *memmove(void* dest, const void* src, size_t n);
 
 struct regs
 {
@@ -13,6 +22,7 @@ struct regs
 	unsigned int eip, cs, eflags, useresp, ss;
 };
 
+void panic();
 void isr_install();
 void irq_install();
 void irq_install_handler(int irq, void (*handler)(struct regs *r));

src/libc/crypto.c

@@ -1,5 +1,10 @@
+// Cryptography routines for blankos/libc
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "crypto.h"
-#include "../libc/stdint.h"
+#include <stdint.h>
 
 int lcg(int seed)
 {

src/libc/crypto.h

@@ -1,9 +1,14 @@
+// Cryptography routines for blankos/libc header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #ifndef CRYPTO_H
 #define CRYPTO_H
 
 #define RAND_MAX 1024
 
-#include "../libc/stdint.h"
+#include <stdint.h>
 
 int lcg(int seed);
 int randint(int seed);

src/libc/ctype.c

@@ -1,12 +1,16 @@
+// Ctype implementation for blankos/libc
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
 
-#include "stdint.h"
+#include <stdint.h>
+#include <stdbool.h>
 
 bool isdigit(char c)
 {
 	return c >= '0' && c <= '9';
 }
 
-
 bool isspace(char c)
 {
 	return c == ' ' || c == '\t' || c == '\n' || c == '\v' || c == '\f' || c == '\r';

src/libc/ctype.h

@@ -1,7 +1,12 @@
+// Ctype implementation for blankos/libc header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #ifndef CTYPE_H
 #define CTYPE_H
 
-#include "stdint.h"
+#include <stdbool.h>
 
 bool isdigit(char c);
 bool isspace(char c);

src/libc/stdint.h

@@ -1,22 +0,0 @@
-#ifndef INCLUDE_STDINT_H
-#define INCLUDE_STDINT_H
-
-typedef signed char int8_t;
-typedef unsigned char uint8_t;
-
-typedef signed short int16_t;
-typedef unsigned short uint16_t;
-
-typedef signed long int int32_t;
-typedef unsigned long int uint32_t;
-
-typedef signed long long int int64_t;
-typedef unsigned long long int uint64_t;
-
-typedef uint8_t bool;
-#define true 1
-#define false 0
-
-#define NULL ((void*)0)
-
-#endif

src/libc/stdio.c

@@ -1,33 +1,50 @@
+// Standard input/output implementation for blankos/libc
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "../kernel/io.h"
 #include "stdio.h"
 #include "string.h"
-#include "stdint.h"
+#include <stdint.h>
 #include "../kernel/system.h"
+#include "../drivers/framebuffer.h"
+#include "../drivers/serial.h"
 
-char* fb = (char *) 0x000B8000;
-const unsigned VGA_WIDTH = 80;
-const unsigned VGA_HEIGHT = 25;
-const unsigned int COLOR = 0x7;
+extern uint32_t* framebuffer;
+extern uint32_t VGA_WIDTH; 
+extern uint32_t VGA_HEIGHT;
 unsigned int VGA_X = 0, VGA_Y = 0;
+extern int scanline;
+
+void draw_cursor(uint32_t color)
+{
+	for (int y=12; y<CURSOR_HEIGHT; y++)
+	{
+		for (int x=0; x<CURSOR_WIDTH; x++)
+		{
+			putpixel(framebuffer, scanline, 32, VGA_X * CURSOR_WIDTH + x, VGA_Y * CURSOR_HEIGHT + y, color);
+		}
+	}
+}
+
+void erase_cursor()
+{
+	draw_cursor(black);
+}
 
 void move_cursor(int x, int y)
 {
-  unsigned short pos = y*VGA_WIDTH+x; 
-
-  outb(FB_CMD_PORT, FB_HIGH_BYTE_CMD);
-  outb(FB_DATA_PORT, ((pos >> 8) & 0x00FF));
-  outb(FB_CMD_PORT, FB_LOW_BYTE_CMD);
-  outb(FB_DATA_PORT, pos & 0x00FF);
+	erase_cursor();
+	VGA_X = x;
+	VGA_Y = y;
+	draw_cursor(white);
 }
 
-void putchar(int x, int y, char c) 
+// stdio wrapper for draw_char in graphics mode
+void putchar(unsigned short int c, int x, int y, uint32_t fg, uint32_t bg)
 {
-  fb[2*(y*VGA_WIDTH+x)] = c;
-}
-
-void putcolor(int x, int y, unsigned int color)
-{
-  fb[2*(y*VGA_WIDTH+x)+1] = color;
+	draw_char(c, x, y, fg, bg);
 }
 
 void clear(void)
@@ -36,55 +53,15 @@ void clear(void)
   {
     for (unsigned int x=0; x<VGA_WIDTH; x++)
     {
-      putchar(x, y, '\0');
-      putcolor(x, y, COLOR);
+      putchar(' ', x, y, black, black);
     }
   }
-  VGA_X = 0;
-  VGA_Y = 0;
-  move_cursor(VGA_X, VGA_Y);
-}
-
-char getchar(int x, int y)
-{
-  return fb[2*(y*VGA_WIDTH+x)];
-}
-
-unsigned int getcolor(int x, int y)
-{
-  return fb[2*(y*VGA_WIDTH+x)+1];
-}
-
-void scroll(int lines)
-{
-  if (lines <= 0 || (unsigned int)lines >= VGA_HEIGHT) return;
-
-  for (unsigned int y = 0; y < VGA_HEIGHT-lines; y++)
-  {
-    for (unsigned int x = 0; x < VGA_WIDTH; x++)
-    {
-      putchar(x, y, getchar(x, y+lines));
-      putcolor(x, y, getcolor(x, y+lines));
-    }
-  }
-
-  for (unsigned int y = VGA_HEIGHT-lines; y<VGA_HEIGHT; y++)
-  {
-    for (unsigned int x = 0; x < VGA_WIDTH; x++)
-    {
-      putchar(x, y, ' ');
-      putcolor(x, y, COLOR);
-    }
-  }
-
-  VGA_Y -= lines;
-  if ((int)VGA_Y < 0) {
-	  VGA_Y = 0;
-  }
+  move_cursor(0, 0);
 }
 
 void putc(char c)
 {
+  erase_cursor();
   switch(c)
   {
     case '\n':
@@ -110,10 +87,10 @@ void putc(char c)
 	      VGA_Y--;
 	      VGA_X = VGA_WIDTH-1;
       }
-      putchar(VGA_X, VGA_Y, ' ');
+      putchar(' ', VGA_X, VGA_Y, white, black);
       break;
     default:
-      putchar(VGA_X, VGA_Y, c);
+      putchar(c, VGA_X, VGA_Y, white, black);
       VGA_X++;
       break;
   }
@@ -123,13 +100,19 @@ void putc(char c)
     VGA_Y++;
     VGA_X = 0;
   }
-  if (VGA_Y >= VGA_HEIGHT) scroll(1);
+  if (VGA_Y >= VGA_HEIGHT) 
+  {
+	serial_printf(3, "VGA_Y=%d, VGA_HEIGHT=%d: Scrolling...\r", VGA_Y, VGA_HEIGHT);
+	scroll();
+  	VGA_Y = VGA_HEIGHT - 1;
+  }	  
 
   move_cursor(VGA_X, VGA_Y);
 }
 
-void colorputc(char c, unsigned int color)
+void colorputc(char c, uint32_t fg, uint32_t bg)
 {
+  erase_cursor();
   switch(c)
   {
     case '\n':
@@ -143,8 +126,7 @@ void colorputc(char c, unsigned int color)
       VGA_X += 4;
       break;
     default:
-      putchar(VGA_X, VGA_Y, c);
-      putcolor(VGA_X, VGA_Y, color);
+      putchar(c, VGA_X, VGA_Y, fg, bg);
       VGA_X++;
       break;
   }
@@ -154,7 +136,14 @@ void colorputc(char c, unsigned int color)
     VGA_Y++;
     VGA_X = 0;
   }
-  if (VGA_Y >= VGA_HEIGHT) scroll(1);
+
+  if (VGA_Y >= VGA_HEIGHT) 
+  {
+	serial_printf(3, "VGA_Y=%d, VGA_HEIGHT=%d: Scrolling...\r", VGA_Y, VGA_HEIGHT);
+	scroll();
+  	VGA_Y = VGA_HEIGHT - 1;
+  }	
+
   move_cursor(VGA_X, VGA_Y);
 }
 
@@ -167,11 +156,11 @@ void puts(const char* str)
   }
 }
 
-void colorputs(const char* str, unsigned int color)
+void colorputs(const char* str, uint32_t fg, uint32_t bg)
 {
   while (*str)
   {
-    colorputc(*str, color);
+    colorputc(*str, fg, bg);
     str++;
   }
 }
@@ -226,22 +215,39 @@ void printf(const char* fmt, ...)
     int length = PRINTF_LENGTH_START;
     int radix = 10;
     bool sign = false;
+    int width = 0;
+    char pad_char = ' ';
 
     argp++;
     while (*fmt)
     {
-    switch(state) {
+        switch (state)
+        {
         case PRINTF_STATE_START:
             if (*fmt == '%')
             {
                 state = PRINTF_STATE_LENGTH;
+                width = 0;
+                pad_char = ' ';
             }
-        else {
+            else
+            {
                 putc(*fmt);
             }
             break;
+
         case PRINTF_STATE_LENGTH:
-        if (*fmt == 'h')
+            if (*fmt == '0')
+            {
+                pad_char = '0';
+                state = PRINTF_STATE_WIDTH;
+            }
+            else if (*fmt >= '1' && *fmt <= '9')
+            {
+                width = *fmt - '0';
+                state = PRINTF_STATE_WIDTH;
+            }
+            else if (*fmt == 'h')
             {
                 length = PRINTF_LENGTH_SHORT;
                 state = PRINTF_STATE_SHORT;
@@ -251,30 +257,47 @@ void printf(const char* fmt, ...)
                 length = PRINTF_LENGTH_LONG;
                 state = PRINTF_STATE_LONG;
             }
-        else {
+            else
+            {
                 goto PRINTF_STATE_SPEC_;
             }
             break;
+
+        case PRINTF_STATE_WIDTH:
+            if (*fmt >= '0' && *fmt <= '9')
+            {
+                width = width * 10 + (*fmt - '0');
+            }
+            else
+            {
+                goto PRINTF_STATE_SPEC_;
+            }
+            break;
+
         case PRINTF_STATE_SHORT:
             if (*fmt == 'h')
             {
                 length = PRINTF_LENGTH_SHORT_SHORT;
                 state = PRINTF_STATE_SPEC;
             }
-        else {
+            else
+            {
                 goto PRINTF_STATE_SPEC_;
             }
             break;
+
         case PRINTF_STATE_LONG:
             if (*fmt == 'l')
             {
                 length = PRINTF_LENGTH_LONG_LONG;
                 state = PRINTF_STATE_SPEC;
             }
-        else {
+            else
+            {
                 goto PRINTF_STATE_SPEC_;
             }
             break;
+
         case PRINTF_STATE_SPEC:
         PRINTF_STATE_SPEC_:
             switch (*fmt)
@@ -294,33 +317,32 @@ void printf(const char* fmt, ...)
             case 'i':
                 radix = 10;
                 sign = true;
-            argp = printf_number(argp, length, sign, radix);
+                argp = printf_number(argp, length, sign, radix, width, pad_char);
                 break;
             case 'u':
                 radix = 10;
                 sign = false;
-            argp = printf_number(argp, length, sign, radix);
+                argp = printf_number(argp, length, sign, radix, width, pad_char);
                 break;
             case 'X':
             case 'x':
             case 'p':
                 radix = 16;
                 sign = false;
-            argp = printf_number(argp, length, sign, radix);
+                argp = printf_number(argp, length, sign, radix, width, pad_char);
                 break;
             case 'o':
                 radix = 8;
                 sign = false;
-            argp = printf_number(argp, length, sign, radix);
+                argp = printf_number(argp, length, sign, radix, width, pad_char);
                 break;
             case 'f': {
-            // Handle floating-point numbers
                 double* dargp = (double*)argp;
                 double d = *(double*)dargp;
                 char buffer[64];
-            dtostrf(d, buffer, 6); // Default precision: 6
+                dtostrf(d, buffer, 6);
                 puts(buffer);
-            argp += 2; // Incrementing by 2 to move past the double argument
+                argp += 2;
                 break;
             }
             default:
@@ -330,6 +352,8 @@ void printf(const char* fmt, ...)
             length = PRINTF_LENGTH_START;
             radix = 10;
             sign = false;
+            width = 0;
+            pad_char = ' ';
             break;
         }
         fmt++;
@@ -338,7 +362,7 @@ void printf(const char* fmt, ...)
 
 const char charset[] = "0123456789abcdef";
 
-int* printf_number(int* argp, int length, bool sign, int radix)
+int* printf_number(int* argp, int length, bool sign, int radix, int width, char pad_char)
 {
     char buffer[32];
     unsigned long long number;
@@ -360,7 +384,8 @@ int* printf_number(int* argp, int length, bool sign, int radix)
             }
             number = (unsigned long long)n;
         }
-      else {
+        else
+        {
             number = *(unsigned int*)argp;
         }
         argp++;
@@ -376,7 +401,8 @@ int* printf_number(int* argp, int length, bool sign, int radix)
             }
             number = (unsigned long long)n;
         }
-      else {
+        else
+        {
             number = *(unsigned long int*)argp;
         }
         argp += 2;
@@ -392,14 +418,16 @@ int* printf_number(int* argp, int length, bool sign, int radix)
             }
             number = (unsigned long long)n;
         }
-      else {
+        else
+        {
             number = *(unsigned long long int*)argp;
         }
         argp += 4;
         break;
     }
 
-  do {
+    do
+    {
         uint32_t rem;
         x86_div64_32(number, radix, &number, &rem);
         buffer[pos++] = charset[rem];
@@ -410,6 +438,13 @@ int* printf_number(int* argp, int length, bool sign, int radix)
         buffer[pos++] = '-';
     }
 
+    int padding = width - pos;
+
+    while (padding-- > 0)
+    {
+        putc(pad_char);
+    }
+
     while (--pos >= 0)
     {
         putc(buffer[pos]);

src/libc/stdio.h

@@ -1,7 +1,13 @@
-#ifndef INCLUDE_STDIO_H
-#define INCLUDE_STDIO_H
+// Standard input/output implementation for blankos/libc header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
 
-#include "stdint.h"
+#ifndef STDIO_H
+#define STDIO_H
+
+#include <stdint.h>
+#include <stdbool.h>
 
 #define FB_GREEN      	  2
 #define FB_DARK_GREY  	  8
@@ -11,23 +17,29 @@
 #define FB_HIGH_BYTE_CMD  14
 #define FB_LOW_BYTE_CMD   15
 
+#define CURSOR_WIDTH  	  8
+#define CURSOR_HEIGHT     16
+
+void draw_cursor(uint32_t color);
+void erase_cursor();
+
 void move_cursor(int x, int y);
-void putchar(int x, int y, char c);
+void putchar(unsigned short int c, int x, int y, uint32_t fg, uint32_t bg);
 void puts(const char* str);
-void colorputs(const char* str, unsigned int color);
 void clear(void);
+void colorputs(const char* str, uint32_t fg, uint32_t bg);
 void putcolor(int x, int y, unsigned int color);
 char getchar(int x, int y);
 unsigned int getcolor(int x, int y);
-void scroll(int lines);
 void putc(char c);
-void colorputc(char c, unsigned int color);
+void colorputc(char c, uint32_t fg, uint32_t bg);
 
 #define PRINTF_STATE_START 			0
 #define PRINTF_STATE_LENGTH 		1
 #define PRINTF_STATE_SHORT 			2
 #define PRINTF_STATE_LONG 			3
 #define PRINTF_STATE_SPEC 			4
+#define PRINTF_STATE_WIDTH 			5
 
 #define PRINTF_LENGTH_START 		0
 #define PRINTF_LENGTH_SHORT_SHORT 	1
@@ -36,10 +48,20 @@ void colorputc(char c, unsigned int color);
 #define PRINTF_LENGTH_LONG_LONG 	4
 
 void printf(const char* fmt, ...);
-int* printf_number(int* argp, int length, bool sign, int radix);
+int* printf_number(int* argp, int length, bool sign, int radix, int width, char pad_char);
 int getch();
 void get_input(char *buffer, int size);
-
 void dtostrf(double val, char *buffer, int precision);
 
+enum Colors
+{
+	// AARRGGBB?
+	white  = 0xFFFFFFFF,
+	black  = 0x00000000,
+	red    = 0x00FF0000,
+	green  = 0x0000FF00,
+	blue   = 0x000000FF,
+	yellow = 0x00FFFF00,
+};
+
 #endif

src/libc/string.c

@@ -1,4 +1,10 @@
-#include "stdint.h"
+// String operations implementation for blankos/libc
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include <stdint.h>
+#include "../kernel/system.h"
 
 int strlen(const char* str)
 {
@@ -68,3 +74,32 @@ char* strtok(char* str, const char* delimiter)
 
 	return token_start;
 }
+
+int atoi(char* str)
+{
+	int result = 0;
+
+	for (int i=0; str[i] != '\0'; i++)
+	{
+		result = result*10 + str[i] - '0';
+	}
+
+	return result;
+}
+
+void strcat(char* dest, const char* src)
+{
+	while (*dest)
+	{
+		dest++;
+	}
+
+	while (*src)
+	{
+		*dest = *src;
+		dest++;
+		src++;
+	}
+
+	*dest = '\0';
+}

src/libc/string.h

@@ -1,8 +1,16 @@
-#ifndef INCLUDE_STRING_H
-#define INCLUDE_STRING_H
+// String operations implementation for blankos/libc header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef STRING_H
+#define STRING_H
 
 int strlen(const char* str);
 int strcmp(const char* str1, const char* str2);
 char* strtok(char* str, const char* delimiter);
+int atoi(char* str);
+void strcat(char* dest, const char* src);
+
 
 #endif

src/programs/bf.c

@@ -1,3 +1,7 @@
+// Simple brainfuck interpreter program
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
 
 #include "../kernel/system.h"
 #include "../libc/stdio.h"

src/programs/ciphers.c

@@ -1,5 +1,12 @@
+// Cipher programs
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "../libc/stdio.h"
 #include "ciphers.h"
+#include "../libc/string.h"
+#include <stdint.h>
 
 void rot13(char* input, char* output)
 {
@@ -32,9 +39,6 @@ void program_rot13()
 	printf("\n%s\n", output);
 }
 
-#include "../libc/string.h"
-#include "../libc/stdint.h"
-
 const char* morse_alphabet[] = {
     ".-",   // A
     "-...", // B

src/programs/ciphers.h

@@ -1,3 +1,8 @@
+// Cipher programs header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #ifndef CIPHERS_H
 #define CIPHERS_H
 

src/programs/conway.c

@@ -1,21 +1,25 @@
+// Conway's Game of Life program
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "conway.h"
 #include "../libc/stdio.h"
 #include "../kernel/system.h"
 #include "../libc/crypto.h"
-#include "../libc/stdint.h"
+#include <stdint.h>
 #include "../drivers/serial.h"
 #include "../libc/string.h"
 
 void print_grid(const unsigned char grid[X][Y])
 {
+	clear();
 	for (int i=0; i<X; i++)
 	{
 		for (int j=0; j<Y; j++)
 		{
-			//(grid[i][j] == LIVE) ? putc(42) : putc(32);
 			if (grid[i][j] == LIVE) {
-				serial_printf(3, "alive");
-			       colorputc(32, 120);
+			       putc(35);
 			} else {
 	       		       putc(32);
 			}		       

src/programs/conway.h

@@ -1,8 +1,13 @@
+// Conway's Game of Life program header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #ifndef CONWAY_H
 #define CONWAY_H
 
-#define X 25
-#define Y 80
+#define X 66
+#define Y 240
 
 #define GENERATIONS 100
 #define DEAD 0

src/programs/cowsay.c

@@ -0,0 +1,72 @@
+// Cowsay-like program
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include "../libc/stdio.h"
+#include "../libc/string.h"
+
+#define MAX_MSG_LEN 128
+
+const char* cow =
+"        \\   ^__^\n"
+"         \\  (oo)\\_______\n"
+"            (__)\\       )\\/\\\n"
+"                ||----w |\n"
+"                ||     ||\n";
+
+void print_bubble(const char* message)
+{
+	int len = strlen(message);
+	puts(" ");
+	for (int i=0; i<len+2; i++)
+	{
+		puts("_");
+	}
+	puts("\n");
+
+	printf("< %s >\n", message);
+
+	puts(" ");
+	for (int i=0; i<len+2; i++)
+	{
+		puts("-");
+	}
+	puts("\n");
+}
+
+void cowsay(char* msg, uint32_t fg, uint32_t bg)
+{
+	print_bubble(msg);
+	colorputs(cow, fg, bg);
+}
+
+void program_cowsay(int argc, char* argv[])
+{
+	if (argc < 2)
+	{
+		printf("Usage: %s <message>\n", argv[0]);
+		return;
+	}
+
+	char message[MAX_MSG_LEN];
+	message[0] = '\0';
+
+	for (int i=1; i<argc; i++)
+	{
+		if (strlen(message) + strlen(argv[i]) + 1 < MAX_MSG_LEN)
+		{
+			strcat(message, argv[i]);
+			if (i < argc-1)
+			{
+				strcat(message, " ");
+			}
+		} else {
+			puts("Too long message.\n");
+			return;
+		}
+	}
+
+	print_bubble(message);
+	printf("%s", cow);
+}

src/programs/math.c

@@ -1,6 +1,9 @@
-// Math expression lexer and parser
+// Basic math expression lexer and parser program
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
 
-#include "../libc/stdint.h"
+#include <stdint.h>
 #include "../kernel/system.h"
 #include "../libc/stdio.h"
 #include "../libc/ctype.h"

src/programs/misc.c

@@ -1,8 +1,12 @@
 // Miscellaneous small programs
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
 
 #include "../libc/stdio.h"
 #include "../kernel/system.h"
 #include "../libc/string.h"
+#include "../drivers/framebuffer.h"
 
 // Print a rainbow colorful text for testing
 
@@ -18,7 +22,7 @@ void program_rainbow()
 
 	for (int i=0; i<COLORS; i++)
 	{
-		colorputs(input_buffer, i);
+		//colorputs(input_buffer, i);
 		puts("\n");
 	}	
 }
@@ -29,7 +33,7 @@ void program_rainbow()
 
 void program_clear()
 {	
-	for (int i=0; i<ROWS; i++) scroll(1);
+	clear();
 }
 
 // Get uptime in ticks
@@ -37,7 +41,7 @@ void program_clear()
 void program_uptime()
 {
 	int ticks = uptime();
-	double seconds = ticks/18.2065; // PIC channel 0 freq
+	double seconds = ticks/18.2065; // PIT channel 0 freq
 	printf("%d ticks\t%f seconds\n", ticks, seconds);
 }
 
@@ -45,7 +49,7 @@ void program_uptime()
 
 void program_help()
 {
-	printf("help\tpanic\twords\tprimes\trainbow\tclear\nmath\tbf\t   uptime   echo\t  sysinfo\tconway\nrot13   morse\n");
+	printf("help\tpanic\twords\tprimes\trainbow\tclear\nmath\tbf\t   uptime   echo\t  sysinfo\tconway\nrot13   morse\tcowsay\n");
 }
 
 // Panic

src/programs/primes.c

@@ -1,6 +1,12 @@
-#include "../libc/stdint.h"
+// Prime number computation program
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include <stdint.h>
 #include "../libc/stdio.h"
 #include "../kernel/system.h"
+#include "../libc/string.h"
 
 #define PRIMES_MAX 1000000
 
@@ -11,15 +17,25 @@ bool isPrime(int n)
 	return true;
 }
 
-void program_primes()
+void program_primes(int argc, char* argv[])
 {
-	for (long long x=0; x<PRIMES_MAX; x++)
+	int primes_max;
+	
+	if (argc == 1)
+	{
+		primes_max = PRIMES_MAX;
+	} else if (argc == 2)
+	{
+		primes_max = atoi(argv[1]);
+	}
+
+	for (long long x=0; x<primes_max; x++)
 	{	
 		if (isPrime(x))
 		{
 				printf("%d ", x);	
 		}
-		delay(2);
+		delay(1);
 	}
 	puts("\n");
 }

src/programs/programs.h

@@ -1,3 +1,8 @@
+// Global program entry points header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #ifndef PROGRAMS_H
 #define PROGRAMS_H
 
@@ -10,6 +15,8 @@ void program_sysinfo();
 void get_cpuid();
 void get_meminfo(unsigned int multiboot_info_address);
 void program_conway();
+void program_cowsay();
+void cowsay(); // Splash screen
 
 // Ciphers
 void program_rot13();
@@ -22,4 +29,5 @@ void program_uptime();
 void program_panic();
 void program_help();
 void program_echo();
+
 #endif

src/programs/sysinfo.c

@@ -1,3 +1,7 @@
+// System information program
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
 
 #include "../kernel/sysinfo.h"
 #include "../libc/stdio.h"

src/programs/words.c

@@ -1,46 +1,211 @@
+// Pseudo-random word generation program
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
 
 #include "../libc/stdio.h"
 #include "../libc/crypto.h"
 #include "../kernel/system.h"
+#include "../libc/string.h"
+
+// Small dictionary
 
 char* words[] =
 {
+	// A
 	"I", "us", "they", "my",
 	"a", "an", "is", "are", "for", "while", "not", "none", "yes", "no",
 	"absolutely", "addition", "additive", "afternoon", "architect", "ask",
-	"be", "blindfold", "brilliant", "boy", "brilliant", "bring", "buddy",
+	"ability", "above", "absence", "academy", "account", "achieve", "acquire",
+	"adapt", "admit", "adventure", "affection", "agenda", "agreement", "airport",
+	"alert", "alibi", "alive", "allow", "almond", "alphabet", "always",
+
+	// B
+	"be", "blindfold", "brilliant", "boy", "bring", "buddy",
+	"balance", "bamboo", "band", "banjo", "bank", "banner", "barrel",
+	"basic", "battery", "beach", "beacon", "beard", "behavior", "believe",
+	"belt", "benefit", "berry", "bicycle", "bingo", "biology", "birthday",
+	"biscuit", "bitter", "blanket", "blizzard", "blossom", "blueprint", "board",
+
+	// C
 	"career", "caterpillar", "change", "cheeky", "chop",
+	"cabin", "cactus", "camera", "candle", "candy", "canoe", "canvas",
+	"capital", "captain", "caravan", "carbon", "carpet", "cartoon", "castle",
+	"casual", "catalog", "catch", "category", "celebrate", "ceremony", "certain",
+	"chain", "chair", "chamber", "charge", "charity", "cheese", "chef",
+
+	// D
 	"decide", "demonstrate", "draw", "druggist",
+	"daisy", "dance", "danger", "daring", "database", "debate", "decade",
+	"decline", "decorate", "decrease", "dedicate", "defeat", "defend", "define",
+	"degree", "delight", "delivery", "demand", "dentist", "deny", "depart",
+	"depth", "describe", "deserve", "desire", "destroy", "develop", "device",
+
+	// E
 	"eagle", "ear", "effort", "evening",
+	"early", "earn", "earth", "ease", "east", "easy", "echo",
+	"eclipse", "economy", "edge", "edit", "educate", "effect", "effort",
+	"egg", "eight", "either", "elder", "elect", "elegant", "element",
+	"elephant", "elevator", "elite", "embark", "embrace", "emerge", "emotion",
+
+	// F
 	"fabric", "famous", "fuse",
+	"face", "factor", "fail", "fair", "fall", "false", "fame",
+	"family", "fancy", "fantasy", "farewell", "farm", "fashion", "fast",
+	"fault", "favor", "feather", "feature", "federal", "feedback", "feeling",
+	"female", "fence", "festival", "fever", "fiber", "fiction", "field",
+
+	// G
 	"generation", "generous", "girl", "gypsy", "grip",
+	"gallery", "game", "garage", "garden", "garlic", "gas", "gate",
+	"gather", "general", "genius", "gentle", "genuine", "geography", "gesture",
+	"ghost", "giant", "gift", "giggle", "ginger", "giraffe", "glance",
+	"glass", "globe", "glory", "glove", "glue", "goal", "gold",
+
+	// H
 	"habit", "handsome", "helmet", "help", "horror",
+	"hair", "half", "hammer", "hand", "handle", "hang", "happen",
+	"harbor", "hard", "harm", "harvest", "hat", "hate", "have",
+	"head", "health", "heart", "heat", "heaven", "heavy", "hedge",
+	"height", "hello", "heritage", "hero", "hesitate", "hidden", "high",
+
+	// I
 	"insist", "inventor", "itself", "ivory",
+	"ice", "idea", "ideal", "identify", "ignore", "ill", "image",
+	"imagine", "impact", "import", "impress", "improve", "impulse", "inch",
+	"include", "income", "increase", "index", "industry", "infant", "inform",
+	"insect", "inside", "inspire", "install", "instead", "insult", "intact",
+
+	// J
 	"jog", "joint", "joke", "judge",
+	"jacket", "jaguar", "jail", "jam", "january", "jar", "jazz",
+	"jealous", "jeans", "jelly", "jewel", "job", "join", "journey",
+	"joy", "judge", "juice", "jump", "jungle", "junior", "justice",
+	"just", "justify", "juggle", "juice", "jumper", "junction", "jury",
+
+	// K
 	"karate", "kebab", "kitchen",
+	"kangaroo", "keen", "keep", "kettle", "key", "keyboard", "kick",
+	"kid", "kidney", "king", "kiss", "kite", "knee", "knife",
+	"knit", "knock", "knot", "know", "knowledge", "koala", "kudos",
+	"keen", "kernel", "kit", "kitten", "knack", "knight", "knock",
+
+	// L
 	"lamb", "lawnmower", "left", "lock",
+	"label", "labor", "lace", "ladder", "lady", "lake", "lamp",
+	"land", "language", "large", "laser", "last", "later", "laugh",
+	"launch", "law", "layer", "lead", "leaf", "learn", "least",
+	"leather", "leave", "lecture", "legal", "legend", "lemon", "length",
+
+	// M
 	"math", "medicine", "most",
+	"machine", "magnet", "mail", "main", "major", "make", "male",
+	"manage", "mango", "manner", "manual", "map", "marble", "march",
+	"mark", "market", "marriage", "master", "match", "material", "matter",
+	"maximum", "mayor", "meal", "mean", "measure", "media", "memory",
+
+	// N
 	"noodles", "nowadays", "nowhere",
+	"nail", "name", "narrow", "nation", "native", "nature", "navy",
+	"near", "neat", "necessary", "neck", "need", "negative", "neglect",
+	"neither", "nerve", "nest", "net", "network", "neutral", "never",
+	"new", "news", "next", "nice", "night", "noble", "noise",
+
+	// O
 	"ocean", "older", "ounce",
+	"object", "observe", "obtain", "occasion", "occupy", "occur", "ocean",
+	"offer", "office", "often", "oil", "old", "olive", "olympic",
+	"omit", "once", "one", "onion", "online", "only", "open",
+	"opera", "opinion", "oppose", "option", "orange", "orbit", "order",
+
+	// P
 	"part", "pathetic", "pastime",
+	"pace", "package", "page", "pain", "paint", "pair", "palm",
+	"panel", "panic", "paper", "parent", "park", "part", "party",
+	"pass", "path", "patient", "pattern", "pause", "peace", "peak",
+	"pen", "pencil", "people", "pepper", "perfect", "perform", "permit",
+
+	// Q
 	"quite", "quits", "quotation",
+	"quality", "quantity", "quarter", "queen", "query", "quest", "quick",
+	"quiet", "quilt", "quit", "quote", "quiz", "quota", "quiver",
+	"quirky", "quaint", "quake", "qualification", "qualify", "quark", "quartz",
+	"queue", "quench", "question", "quote", "quiver", "quorum", "quote",
+
+	// R
 	"race", "raise", "reality",
+	"rabbit", "race", "radio", "rain", "raise", "random", "range",
+	"rapid", "rare", "rate", "rather", "ratio", "reach", "react",
+	"read", "ready", "real", "reason", "rebel", "recall", "receive",
+	"recipe", "record", "recover", "reduce", "refer", "reflect", "reform",
+
+	// S
 	"safe", "scare", "screen",
+	"sack", "sail", "salad", "salt", "same", "sample", "sand",
+	"save", "scale", "scan", "scar", "scene", "school", "science",
+	"score", "scratch", "scream", "screen", "script", "search", "season",
+	"seat", "second", "secret", "section", "secure", "see", "seed",
+
+	// T
 	"taught", "temple", "that", "this",
+	"table", "tackle", "tail", "take", "tale", "talent", "talk",
+	"tank", "tape", "target", "task", "taste", "tax", "teach",
+	"team", "tear", "technology", "telephone", "television", "temperature", "tend",
+	"tennis", "tent", "term", "test", "text", "thank", "theory",
+
+	// U
 	"unable", "unkind", "usual",
+	"umbrella", "unable", "uncle", "under", "undo", "unfair", "unfold",
+	"union", "unique", "unit", "universe", "unknown", "unless", "unlike",
+	"unlock", "until", "unusual", "update", "upgrade", "upon", "upper",
+	"upset", "urban", "urge", "use", "usual", "utility", "utter",
+
+	// V
 	"velvet", "vivid", "vote",
+	"vacuum", "valid", "valley", "value", "vampire", "van", "vase",
+	"vast", "vault", "vector", "vehicle", "velvet", "vendor", "venture",
+	"verb", "verify", "version", "vessel", "veteran", "veto", "vibrate",
+	"victory", "video", "view", "village", "violin", "virtue", "virus",
+
+	// W
 	"we", "warm", "watch",
+	"wage", "wait", "walk", "wall", "wander", "want", "war",
+	"wash", "waste", "watch", "water", "wave", "way", "wealth",
+	"weapon", "wear", "weather", "weave", "wedding", "week", "weight",
+	"welcome", "well", "west", "wheel", "when", "whisper", "white",
+
+	// X
 	"xylophone",
+	"xenon", "xenophobia", "xerox", "xmas", "x-ray", "xylophone", "xylem",
+
+	// Y
 	"yolk", "young", "your",
+	"yard", "yarn", "year", "yell", "yellow", "yes", "yesterday",
+	"yet", "yield", "yogurt", "yoke", "youth", "yawn", "yearn",
+	"yacht", "yummy", "yogurt", "yoga", "yardstick", "yonder", "yummy",
+
+	// Z
 	"zebra", "zodiac", "zucchini",
+	"zero", "zone", "zoo", "zoom", "zeal", "zip", "zigzag",
+	"zenith", "zest", "zipper", "zombie", "zonal", "zinc", "zephyr"
 };
 
 int words_size = sizeof(words)/sizeof(words[0]);
 
-// Generates 5 random words
-void program_words()
+// Generates random words
+void program_words(int argc, char* argv[])
 {
-	for (int i=0; i<10; i++)
+	int amount;
+
+	if (argc == 1)
+	{
+		amount = 10;
+	} else if (argc == 2)
+	{
+		amount = atoi(argv[1]);
+	}
+
+	for (int i=0; i<amount; i++)
 	{
 		int random = randint(global_ticks);
 		char* word = words[random%words_size];