Merge pull request #2 from xamidev/cleanup

Codebase cleanup & harmonization

README.md

@@ -2,26 +2,9 @@
 
 # BlankOS
 
-Rewritten monolithic, ring 0, lower-half, singletasking kernel for the x86 processor architecture, using GRUB (eltorito) as bootloader. Emulation was tested on 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, such as...
-- A brainfuck interpreter
-- An arithmetic calculator
-- ROT13 and Morse cipher programs
-- Conway's Game of Life
-- And some more...
-
 ## Usage
 
 Download the latest BlankOS disk image from the "Releases" tab, and start it using the QEMU emulator:
@@ -54,19 +37,6 @@ 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!
 
-## Debugging (QEMU w/ GDB)
-
-```
-make debug
-```
-
-In another shell:
-
-```
-gdb kernel.elf
-(gdb) target remote localhost:1234
-```
-
 ## Documentation
 
 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)*
@@ -82,7 +52,7 @@ Two other documents are available to help you understand the project better. One
 - Ralf Brown's Interrupt List
 - the [little book about OS development](https://littleosbook.github.io/) by Erik Helin and Adam Renberg
 
-### Roadmap
+### Features / Roadmap
 
 - [X] Booting with GRUB
 - [X] Common basic structures (IDT, GDT, ISRs, IRQs)
@@ -95,7 +65,7 @@ Two other documents are available to help you understand the project better. One
 - [ ] Getting to Ring-3 (userspace)
 - [ ] Multitasking (via round robin scheduling)
 - [ ] Advanced/other drivers (video, SB16, RTC, Ethernet)
-- [ ] UEFI support
+- [X] UEFI support
 - [ ] ELF parsing
 - [ ] System calls
 - [ ] GUI

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.

makefile

@@ -1,5 +1,5 @@
 CC = i386-elf-7.5.0-Linux-x86_64/bin/i386-elf-gcc
-CFLAGS = -g -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

src/drivers/ata.c

@@ -1,27 +1,12 @@
-#include "../libc/stdint.h" 
+// 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"
-#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
 
 static inline uint16_t inw(uint16_t port) {
     uint16_t result;

src/drivers/ata.h

@@ -1,6 +1,34 @@
+// 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();
 

src/drivers/framebuffer.c

@@ -1,11 +1,16 @@
-#include "../libc/stdint.h"
+// 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 uint32_t *g_framebuffer;
+extern char* framebuffer;
 
-void putpixel(uint32_t* fb, int pitch, int bpp, int x, int y, uint32_t color) // framebuffer pointer, x, y, color
+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));
@@ -13,14 +18,6 @@ void putpixel(uint32_t* fb, int pitch, int bpp, int x, int y, uint32_t color) //
 	}
 }
 
-extern char* framebuffer;
-extern int scanline;
-extern char _binary_include_fonts_UniCyr_8x16_psf_start;
-uint16_t* unicode;
-
-#define PIXEL uint32_t
-
-// Character, cursor X, cursor Y, foreground, background
 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;

src/drivers/framebuffer.h

@@ -1,6 +1,19 @@
+// 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 {
@@ -9,7 +22,6 @@ typedef struct {
     uint8_t characterSize; // PSF character size.
 } PSF1_Header;
 
-
 #define PSF_FONT_MAGIC 0x864ab572
 
 typedef struct {
@@ -23,7 +35,6 @@ typedef struct {
     uint32_t width;         /* width in pixels */
 } PSF_font;
 
-//extern const unsigned char font[512][64];
 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();

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"
-
+#include "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
 
 unsigned char kbdus[128] =
 {

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/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"
@@ -279,4 +284,3 @@ void serial_printf(int errlevel, const char* fmt, ...)
   }
   serial_puts("\n");
 }
-

src/drivers/serial.h

@@ -1,5 +1,10 @@
-#ifndef INCLUDE_SERIAL_H
+// Serial I/O driver header
-#define INCLUDE_SERIAL_H
+// 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"
 

src/kernel/gdt.c

@@ -1,22 +1,11 @@
+// Global descriptor table setup
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
 #include "gdt.h"
 #include "../libc/stdio.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));
-
 struct gdt_entry gdt[3];
 struct gdt_ptr gp;
 

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

@@ -1,22 +1,12 @@
+// 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"
 #include "../libc/stdio.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));
-
 struct idt_entry idt[256];
 struct idt_ptr idtp;
 

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
+// Raw CPU port I/O kernel module header 
-#define INCLUDE_IO_H
+// 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

@@ -1,17 +1,22 @@
+; 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:
-  mov al, [esp + 8]
+    mov al, [esp + 8]
-  mov dx, [esp + 4]
+    mov dx, [esp + 4]
-  out dx, al
+    out dx, al
-  ret
+    ret
 
 global inb
 
 inb:
-  mov dx, [esp + 4]
+    mov dx, [esp + 4]
-  in al, dx
+    in al, dx
-  ret
+    ret
 
 global x86_div64_32
 

src/kernel/irq.c

@@ -1,3 +1,8 @@
+// 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"

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);
@@ -116,4 +120,3 @@ void fault_handler(struct regs *r)
 		for (;;);
 	}
 }
-

src/kernel/kheap.c

@@ -1,6 +1,10 @@
-#include "kheap.h"
+// Kernel heap management
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
 
-#include "../libc/stdint.h"
+#include "kheap.h"
+#include <stdint.h>
 
 extern uint32_t end;
 uint32_t placement_address = (uint32_t)&end;

src/kernel/kheap.h

@@ -1,7 +1,12 @@
+// 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 "../libc/stdint.h"
+#include <stdint.h>
 
 uint32_t kmalloc_a(uint32_t sz);
 uint32_t kmalloc_p(uint32_t sz, uint32_t *phys);

src/kernel/kmain.c

@@ -1,3 +1,8 @@
+// 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"
@@ -5,43 +10,15 @@
 #include "system.h"
 #include "paging.h"
 #include "../drivers/ata.h"
-#include "../libc/stdint.h" 
+#include <stdint.h>
 #include "../drivers/framebuffer.h"
-
+#include "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;
-
 
 void kmain(multiboot2_info *mb_info)
 {
-
 	multiboot2_tag_framebuffer *fb_info = NULL;
 
-uint8_t *tags = mb_info->tags;
+    uint8_t *tags = mb_info->tags;
     while (1) {
         uint32_t tag_type = *((uint32_t*) tags);
         uint32_t tag_size = *((uint32_t*) (tags + 4));
@@ -54,61 +31,43 @@ uint8_t *tags = mb_info->tags;
         tags += ((tag_size + 7) & ~7);
     }
 
-    	serial_printf(3, "Framebuffer Address: 0x%x\r", fb_info->framebuffer_addr);
+    serial_printf(3, "Framebuffer Address: 0x%x\r", fb_info->framebuffer_addr);
 	serial_printf(3, "Framebuffer Width: %u\r\n", fb_info->framebuffer_width);
 	serial_printf(3, "Framebuffer Height: %u\r\n", fb_info->framebuffer_height);
 	serial_printf(3, "Framebuffer Pitch: %u\r\n", fb_info->framebuffer_pitch);
 	serial_printf(3, "Framebuffer BPP: %u\r\n", 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 pitch = fb_info->framebuffer_pitch;
         uint32_t bpp = fb_info->framebuffer_bpp;
 
-	
+        //8x16 font, not padded 
-	//8x16 font, not padded 
+        VGA_WIDTH = width/8;
-	VGA_WIDTH = width/8;
+        VGA_HEIGHT = height/16;
-	VGA_HEIGHT = height/16;
+        scanline = width * (bpp/8);	
-
-	scanline = width * (bpp/8);	
-
-	
-	/* TEST print charset
-	int y_offset = 2;
-	for (int i=0; i<512; i++)
-	{
-		if (i%(width/9)==0) y_offset++;
-		draw_char(0+i, 0+i, y_offset, white, black);
-	}
-	*/
     }
 
     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();
-  init_serial();
+    gdt_install();
-  gdt_install();
+    idt_install();
-  idt_install();
+    isr_install();
-  isr_install();
+    irq_install();
-  irq_install();
+    __asm__ __volatile__("sti");
-  __asm__ __volatile__("sti");
  
-  //init_paging();
+    //init_paging();
+    //test_read_sector();
+    //uint32_t *ptr = (uint32_t*)0xA0000000;
+    //uint32_t do_page_fault = *ptr;
 
-  //test_read_sector();
+    timer_install();
-
+    keyboard_install();
-  //uint32_t *ptr = (uint32_t*)0xA0000000;
+    printf("[kernel] spawning shell...\n"); 
-  //uint32_t do_page_fault = *ptr;
+    shell_install();
-
-  timer_install();
-  keyboard_install();
-  printf("[kernel] spawning shell...\n"); 
-  shell_install();
- 
 }

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

@@ -1,3 +1,8 @@
+; 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 .multiboot_header
@@ -6,9 +11,9 @@ align 8
 
 ; ASM macros
 
-MAGIC_NUMBER      equ 0xe85250d6  ; multiboot2 magic 
+MAGIC_NUMBER      equ 0xe85250d6  	; multiboot2 magic 
-FLAGS             equ 0x0	  ; 32-bit protected mode for i386
+FLAGS             equ 0x0	  		; 32-bit protected mode for i386
-HEADER_LEN	  equ 44 	  ;  Tags=2+2+4+4+4+4+2+2+4=28
+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)
@@ -43,14 +48,12 @@ KERNEL_STACK_SIZE equ 4096
 extern kmain
 
 loader:
-  cli
+  	cli
-  ; mov eax, 0xCAFEBABE
+  	push ebx
-  ; push dword 42
+  	call kmain
-  push ebx
-  call kmain
 
 .loop:
-  jmp .loop
+  	jmp .loop
 
 global gdt_flush
 extern gp
@@ -206,5 +209,5 @@ irq_common_stub:
 section .bss
 align 4 
 kernel_stack:
-  resb KERNEL_STACK_SIZE
+  	resb KERNEL_STACK_SIZE
-  mov esp, kernel_stack + KERNEL_STACK_SIZE
+  	mov esp, kernel_stack + KERNEL_STACK_SIZE

src/kernel/paging.c

@@ -1,18 +1,19 @@
-#include "../libc/stdint.h"
+// 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;
 
-#define INDEX_FROM_BIT(a) (a/(8*4))
-#define OFFSET_FROM_BIT(a) (a%(8*4))
-
 static void set_frame(uint32_t frame_addr)
 {
 	uint32_t frame = frame_addr/0x1000;

src/kernel/paging.h

@@ -1,12 +1,21 @@
+// 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 "../libc/stdint.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 rw			: 1;
 	uint32_t user		: 1;
 	uint32_t accessed	: 1;
 	uint32_t dirty		: 1;

src/kernel/shell.c

@@ -1,13 +1,17 @@
+// 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 <stdint.h>
 
 #define BUFFER_SIZE 256
 #define MAX_COMMANDS 16
-#define MAX_ARGS 64
+#define MAX_ARGS     64
-
 
 char* ascii_title =
 "\n"
@@ -17,7 +21,6 @@ char* ascii_title =
 "----------------------------------------------\n"
 "\n";
 
-
 typedef void (*command_func_t)(int argc, char *argv[]);
 
 typedef struct

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

@@ -1,5 +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 "../libc/stdint.h"
+#include <stdint.h>
 
 void *memset(void *dest, char val, size_t count)
 {

src/kernel/system.h

@@ -1,9 +1,15 @@
+// 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 "../libc/stdint.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);

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

@@ -1,24 +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)
-
-typedef unsigned int uintptr_t;
-
-#endif

src/libc/stdio.c

@@ -1,7 +1,12 @@
+// 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"
@@ -10,9 +15,6 @@ extern uint32_t* framebuffer;
 extern uint32_t VGA_WIDTH; 
 extern uint32_t VGA_HEIGHT;
 unsigned int VGA_X = 0, VGA_Y = 0;
-
-#define CURSOR_WIDTH  8
-#define CURSOR_HEIGHT 16
 extern int scanline;
 
 void draw_cursor(uint32_t color)

src/libc/stdio.h

@@ -1,16 +1,24 @@
-#ifndef INCLUDE_STDIO_H
+// Standard input/output implementation for blankos/libc header
-#define INCLUDE_STDIO_H
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
 
-#include "stdint.h"
+#ifndef STDIO_H
+#define STDIO_H
 
-#define FB_GREEN      2
+#include <stdint.h>
-#define FB_DARK_GREY  8
+#include <stdbool.h>
+
+#define FB_GREEN      	  2
+#define FB_DARK_GREY  	  8
 
 #define FB_CMD_PORT       0x3D4
 #define FB_DATA_PORT      0x3D5
 #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();
@@ -26,24 +34,23 @@ unsigned int getcolor(int x, int y);
 void putc(char c);
 void colorputc(char c, uint32_t fg, uint32_t bg);
 
-#define PRINTF_STATE_START 		0
+#define PRINTF_STATE_START 			0
 #define PRINTF_STATE_LENGTH 		1
-#define PRINTF_STATE_SHORT 		2
+#define PRINTF_STATE_SHORT 			2
-#define PRINTF_STATE_LONG 		3
+#define PRINTF_STATE_LONG 			3
-#define PRINTF_STATE_SPEC 		4
+#define PRINTF_STATE_SPEC 			4
-#define PRINTF_STATE_WIDTH 		5
+#define PRINTF_STATE_WIDTH 			5
 
 #define PRINTF_LENGTH_START 		0
 #define PRINTF_LENGTH_SHORT_SHORT 	1
 #define PRINTF_LENGTH_SHORT 		2
-#define PRINTF_LENGTH_LONG 		3
+#define PRINTF_LENGTH_LONG 			3
 #define PRINTF_LENGTH_LONG_LONG 	4
 
 void printf(const char* fmt, ...);
 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

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)
 {

src/libc/string.h

@@ -1,5 +1,10 @@
-#ifndef INCLUDE_STRING_H
+// String operations implementation for blankos/libc header
-#define INCLUDE_STRING_H
+// 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);

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

@@ -1,8 +1,13 @@
+// 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"
 

src/programs/conway.h

@@ -1,3 +1,8 @@
+// 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
 

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

@@ -1,4 +1,7 @@
 // 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"
@@ -30,7 +33,7 @@ void program_rainbow()
 
 void program_clear()
 {	
-	for (int i=0; i<ROWS; i++) scroll();
+	clear();
 }
 
 // Get uptime in ticks
@@ -38,7 +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);
 }
 

src/programs/primes.c

@@ -1,4 +1,9 @@
-#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"
 

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
 
@@ -22,4 +27,5 @@ 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

@@ -1,3 +1,7 @@
+// 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"
@@ -37,7 +41,7 @@ char* words[] =
 
 int words_size = sizeof(words)/sizeof(words[0]);
 
-// Generates 5 random words
+// Generates random words
 void program_words()
 {
 	for (int i=0; i<10; i++)