WalOS

It's a stupid small x86 OS... Just learning OS development by book and datasheet.

Build on Linux(Ubuntu 14.04)

$ sudo apt-get install vgabios bochs bochs-x bximage
$ sudo apt-get install gcc git
$ git clone https://github.com/WalonLi/WalOS.git
$ cd WalOS
$ ./start.sh
<bochs:1> c

---

Reference

Write your own OS with Free and Open source software(楊文博)

Orange'S 一個作業系統的實現(于淵)

程式設計師的自我修養：連結、載入、程式庫

Intel® 64 and IA-32 Architectures Software Developer’s Manual

Executable and Linkable Format (ELF) document

AT Attachment with Packet Interface

---

System call(2015/6/30)

printf      (for print message on console)
send_recv   (for IPC)
    |
    ---- MSG_HW_INTERRUPT
    |
    ---- MSG_GET_TICKS

Current Flow(2015/6/26)

            -------------------------------------------------------
BootSector  |       Boot to BootSector
            |
            |       Load loader
Loader      |       Jump to loader
            |
            |       Load kernel
Kernel      |       Jump to kernel
            |
            |       Initial and switch to kernel GDT
            |
            |       Initial hardware interrupt controller(8259A)
            |       Initial software interrupt(system call)
            |       Initial IDT
            |       Initial TSS and LDT descriptor in GDT.
            |
            |
            |
            |       Initial Process Table
            |       Initial Clock interrupt
            |
            |       Prepare printx/send_recv system call.
            |       Prepare IPC(doing now)
            |       Process start...
            |
            -------------------------------------------------------

---

Memory Layout(2015/5/17)

        -------------------------
        |                       |
        |     Page Tables       |
0x101000|-----------------------|
        |        PDT            |
0x100000|-----------------------|
        |                       |
        |     Hardware          |
        |        Reserved       |
        |                       |
        |-----------------------|
        |        EBDA           |
        |-----------------------|
        |     loader.bin        |
        |                       |
0x90000 |-----------------------|
        |     kernel.bin        |
        |                       |
0x80000 |-----------------------|
        |     kernel            |
        |           Entry       |
0x30000 |-----------------------|
        |                       |
        |                       |
        |                       |
        |                       |
        |                       |
        |                       |
0x0     -------------------------

---

Flat File System Layout(Orange's)(7/26)

-----------------------------
|                           |
|                           |
|                           |
|                           |
|                           |
|           DATA            |
|                           |
|                           |
|                           |
|                           |
|---------------------------|
|           root            |
|---------------------------|
|                           |
|       i-node array        |
|                           |
|---------------------------|
|                           |
|       sector map          |
|                           |
|---------------------------|
|       i-node map          |
|---------------------------|
|       super block         |
|---------------------------|
|       boot sector         |
-----------------------------

GNU GENERAL PUBLIC LICENSE
Copyright (C) 2015  WalonLi

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.