1 Attachment(s)
Writing My Own Operating System
Hello Assembly Guru's!
I am teaching myself assembly and needed a good project to stay motivated while learning to use it.
So what i have done here is pieced together my own bootstrapper and operating system from different ideas i have seen on the internet.
This booter loads from a floppy disk (FAT12) and runs in 16 bit real mode.
I have written some basic input/output handler routines also.
I would like you to download my code and have a look see.
Any ideas or comments about what i have so far would be greatly appreciated.
Theres enough stuff in this attatchment to get it all working on your system.
If you have any questions, just leave a reply and i will answer them.
Ok, thanks and happy coding...
Re: Writing My Own Operating System
Aww man! that's so awesome! I took an assembly class a few semesters ago, at the university i attend, and ever since I've wanted to write an operating system. I'm not nearly as advanced as you are, so I doubt I'd get anywhere, but it looks really friggin cool :P
Re: Writing My Own Operating System
I am just learning assembly myself.
I cant afford a book or schooling so i researched ASM on the net.
I tried to keep the code simple so it would be easy to understand.
The next step is to put the the command handlers into a table.
This will reduce the amount of code it takes to process an input command.
This will contain an input command and a function pointer for that command.
I write graphics code everyday in 'C' so it is my goal to eventually write an OS that will be based on my 3d game engine.
I am a long way away from that...
I think if this is done right i will have a very fast OS with tons of polygon pumping power.
If anyone has any ideas that would help speed up my design i would be very happy to hear them.
ok, thanks for your time and for your posts.
Re: Writing My Own Operating System
Hey, not trying to discourage you, but here you wont find much of a testing crowd, but I think you should go online with this project (like sourceforge.net) and publish it over there and let other people get involved in testing, reviewing etc.
Re: Writing My Own Operating System
Re: Writing My Own Operating System
Does anyone have a bootstrapper for a usb storage device?
Or maybe some ideas or info on how i can write one?
I would like to store my OS on that instead of the floppy i use now.
As of now i am using an old 286 lappy to code ASM and i would like to do it on my 386 desktop but it has no floppy drive, and i wish not to store it on the hard drive.
Re: Writing My Own Operating System
I took a look at some of the code you have--pretty interesting stuff you got there. I took a class last semester specifically for operating systems. We got as far as being able to load and run processes (.exe files), as well as implementing file-systems (FAT32), dealing with interrupts, and terminal/keyboard/mouse input. Oh yeah, and page tables--that was fun. No sarcasm there at all ;) I might be able to help you out, if you had any questions or anything like that--just out of curiosity, how far were you intending on going with this?
Re: Writing My Own Operating System
I have done it on microcontrollers. USB mass storage is essentially a SCSI interface sent over a USB bus. For examples, take a look at source for almost any USB handling micro. I know that SiLabs (www.silabs.com) has Mass Storage examples written mostly in C for their 34x micros.
-Erik
Re: Writing My Own Operating System
Quote:
Originally Posted by Liminal
I might be able to help you out, if you had any questions or anything like that--just out of curiosity, how far were you intending on going with this?
First i would like to place the menu commands into a table, this would make any changes or additions to the menu a lot easier to do later on.
As for how far i will take this project, well what im aiming for is a game engine that runs on its own operating system.
Right now im a Win32-OpenGL graphics code monkey, but as we all know that running windows for a game platform is very slow due to the overhead of the os.
I would like to have my own os and drop the opengl library all-together.
This project is purely for my buddies and i to link up and play my games online.
If you can make any parts of my code better i would like to know how.
I have no schooling in computer sciences and tought myself how to code, so what i know about asm is not nearly enough to do it all myself.
Re: Writing My Own Operating System
Nice! You can go to www.osdev.org, and joing a large community. You can also go to rohitab.com forums and they have a nice OS tutorial in the Source Code section.
Re: Writing My Own Operating System
Quote:
Originally Posted by bitshifter420
Does anyone have a bootstrapper for a usb storage device?
Or maybe some ideas or info on how i can write one?
Do you have the answer for this?
Quote:
Originally Posted by bitshifter420
i wish not to store it on the hard drive.
I assume there is a good reason for that but I am curious what that is. Why do you "wish not to store it on the hard drive"?
The original IBM PC could boot from the keyboard but I do not know the details of how to do that. I just know that I studied the IBM BIOS many years ago and was surprised by the code to boot from the keyboard.
Have you considered a virtual machine? I am not familiar with the details of virtual machines from Microsoft, but a virtual machine would probably help, at least for development.
Did you know that someone wrote an OS for a micro-controler that also had a HTTP server?
Have you considered making a development environment (an editor and an assembler) that executes in your OS?
Re: Writing My Own Operating System
Quote:
Originally Posted by Sam Hobbs
I assume there is a good reason for that but I am curious what that is. Why do you "wish not to store it on the hard drive"?
Mainly so it is removable/portable and easy to make changes to later on.
You can hardly find a new pc that has a floppy drive, so usb mass storage device seems to be the next best thing to store it on.
Ive seen a lot of os examples written in C but i want to use asm only.
Im currently using nasmw for an assembler, it seems like the simplest one i could find and is easy to use.
My old 286 lappy has a 6 inch greyscale monitor so you can imagine how much fun that is to play with.
Getting this os onto a usb for my 386 desktop is kinda ontop of my list right now.
Then ill start work on the a20 gate and 32 bit protected mode.
Re: Writing My Own Operating System
Quote:
Originally Posted by bitshifter420
You can hardly find a new pc that has a floppy drive, so usb mass storage device seems to be the next best thing to store it on.
Or CD-ROM, but I don't know how to easily test that. Probably if you were to develop the capability of booting from hard drive then that can be used for a CD-ROM also. Are you familiar with the El-Torito format? A CD-ROM can also emulate a hard drive.
Can Linux boot from a USB device? If so, then you should be able to find source code for that.
Quote:
Originally Posted by bitshifter420
Ive seen a lot of os examples written in C but i want to use asm only.
I said nothing about C; if you understood me to have implied that, then you misunderstand.
Quote:
Originally Posted by bitshifter420
Then ill start work on the a20 gate and 32 bit protected mode.
I said nothing about 16-bits or 32-bits.
Re: Writing My Own Operating System
Quote:
Originally Posted by bitshifter420
Does anyone have a bootstrapper for a usb storage device?
Or maybe some ideas or info on how i can write one?
I would like to store my OS on that instead of the floppy i use now.
Try doing a search. I did and got the following, but you should do the search yourself also.
Also, have you looked around in usb.org?
http://www.usb.org/developers/devclass_docs/HID1_11.pdf
Re: Writing My Own Operating System
How are you doing?
I downloaded the x3dOS.zip file but I did not understand how to create a bootable floppy. I understand that it is still being developed and you are not ready for it to be used by most people.
If you have an improved version that you want others to try and you think it is easier to understand then I am interested in trying it.
Even if you don't have anything for us to try, I am curious about whether you have made progress.
Re: Writing My Own Operating System
Hi Sam, im sorry for not providing good install instructions so here...
Step 1) Insert clean floppy and format to FAT12.
Step 2) Double left click the 'compile.bat' file. (This compiles the asm files.)
Step 3) Double left click the 'mkfloppy.bat' file. (This writes the data to disk.)
Step 4) Adjust you BIOS to look in floppy drive first for bootsector.
Step 5) Restart your pc and it you should be in my os.
To exit my os simply remove the floppy and type 'exit' into the command console.
(This causes re-boot, and since no bootsector is found in floppy, your os gets it)
As for doing any work on the code, the answer is no.
I no longer use nasm compiler since switching to fasm compiler.
Sometime in the future i will port the code syntax and go from there.
Re: Writing My Own Operating System
I love the idea of a separate sleek OS for gaming and graphics. I wish I could read what you have written, but my experience with Assembly is using MIPS for a class, lol...
Re: Writing My Own Operating System
Thank you for the instructions. It seems simple and obvious and I don't remember why it did not work for me; it has been a while. I probably did not expect to have to compile (assemble) it. Now that I know there is not a newer version I will try again.
Does it help to use a virtual machine for development purposes? I know that you are not currently working on it but virtual machines have become quite useful in the past few years.
Re: Writing My Own Operating System
I used boch's emulator for writing/testing bootstrapper and kernel.
The shell and inout stuff are all bios driven so it was written/tested
in a seperate dos .com module, then plugged in later very easily.
I do have most of the new inout command buffer/router and stuff done for the next version!
It now incorporates a command lookup table for command function handlers, cool stuff.
Now its super easy to add a new command and handler to the list.
Right now i dont have either of my 286,s with me so all i can play with
is the stuff that can be written/tested in dos .com module.
Next on the todo list is the file handling stuff, maybe by spring?
Re: Writing My Own Operating System
There are virtual machines you can use within Windows; VirtualBox is one, which I think is an improved version of QEMU. Parallels had a special offer in which they gave away their VM, but I assume that offer is not available now. Microsoft has a VM and I think there is one more that is available for free.
