Welcome to FoolOS
=================

![FoolOS Logo](https://gitweb.softwarefools.com/?p=miguel/fool-os.git;a=blob_plain;f=img/logo.png;hb=HEAD)

Multiboot
---------
The FoolOS Kernel is following the Multiboot Specification (0.6.96) 
providing a multiboot header and the entry point _start().

This in turn calls the C function kernel_main().

Disclaimer
----------

THIS IS A WORK IN PROGRESS.

This is a simple and useless "operating system", with a very basic set 
of features. It is the fruit of my fundamental explorations of the x86 
architecture and operating system design.

Copyright M.Idziorek 2014-2015,2018 <m.i@gmx.at> unless stated otherwise.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. 
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY 
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Prequisites
-----------

GCC CROSS-COMPILER (i686-elf)

    https://wiki.osdev.org/GCC_Cross-Compiler (18 AUG 2018)
    ftp://ftp.fu-berlin.de/unix/languages/gcc/releases/gcc-8.2.0/gcc-8.2.0.tar.gz
    https://sunsite.icm.edu.pl/pub/gnu/binutils/binutils-2.31.1.tar.gz

NEWLIB

    https://wiki.osdev.org/Porting_Newlib (18 AUG 2018)
    ftp://sourceware.org/pub/newlib/newlib-3.0.0.20180802.tar.gz
    https://ftp.gnu.org/gnu/autoconf/autoconf-2.68.tar.gz
    https://ftp.gnu.org/gnu/automake/automake-1.11.6.tar.gz

Usage
-----
Use the FoolOS.iso in your favourite emulator or `dd` to an usb stick 
and test on real hardware.

Supported Platforms
-------------------
TODO: update/recheck

FoolOS is tested/developed on the following emulators/machines

* bochs 2.6.6 (compiled with: ./configure --enable-clgd54xx --enable-a20-pin --enable-debugger --enable-disasm --enable-e1000 --with-x --with-x11 --with-term --enable-smp) (add -lpthread to LIBS in the Makefile!)
* bochs 2.6.8 (compiled with: ./configure --enable-clgd54xx --enable-a20-pin --enable-debugger --enable-disasm --enable-e1000 --with-x --with-x11 --with-term --enable-smp) (add -lpthread to LIBS in the Makefile!)
* qemu 1.1.2
* virtual box 4.1.18
* Acer Aspire 1810TZ (Notebook)
* Q6600 on Asus p5n32-e sli plus (Desktop PC)
* 4790K on Asus (Desktop PC)

Features
--------

Please note that all features are only very rudimentary and mostly buggy.

* Booting with Multiboot (grub)
* 32-bit protected mode
* Interrupt handling
* Task scheduling 
* ELF binaries
* PIT support / Timing
* PIC support & Interrupt handling framework
* Physical memory management
* Virtual memory management
* Multitasking
* Keyboard driver
* Spinlocks
* Simple Shell
* Simple Ext2 driver (read-only)
* PS2 Mouse driver
* ACPI / MP
* Symmetric Multiprocessing
* PCI bus scanning
* Kernel and Userspace Tasks (ring 0/ring 3)

Discontinued Features
---------------------

* Floppy Disk Driver
* Custom Bootloader (2 stages)

Todos
-----

* Unit Tests
* Newlib Reeentrancy Struct
* Ethernet driver E1000 / NS2000 & Networking stack (ipxe network drivers?)
* Porting (ncurses, gcc, binutils, vim, apache...)
* Posix getdents
* GCC optimizations (break kernel?)
* Writing to ext2 RAM-image
* Mutes
* Flush TLB
* GUI / Window Manager (update\_rect, etc..)

REFERENCES
==========

    http://www.brokenthorn.com/Resources/OSDev17.html
    http://www.jamesmolloy.co.uk/tutorial_html/9.-Multitasking.html
    http://pdos.csail.mit.edu/6.828/2011/labs/lab6/
    http://pdos.csail.mit.edu/6.828/2011/xv6.html
    http://www.nongnu.org/ext2-doc/
    http://www.osdever.net/tutorials/view/multiprocessing-support-for-hobby-oses-explained
    http://forum.osdev.org/viewtopic.php?f=1&t=10944
    http://wiki.osdev.org/Virtual_8086_Mode
    http://wiki.xomb.org/index.php?title=ACPI_Tables
    http://wiki.osdev.org/Hosted_GCC_Cross-Compiler
    https://sourceware.org/newlib/
    and many many more...