Hello and mi first question

DeepOS · Post by **DeepOS** » Thu Feb 21, 2008 6:54 am

Hello guys!!

I'm a dummy in OS development. Now, I'm trying to develop a Spanish OS (I'm from Spain). My OS is based in a "Shell-type" OS, I develop many comands and my next task is implement the filesystem. Can anyone give me some texts that's explain me how can I implement the filesystem??? I've searched in the OSdev wiki, in the Osdever tutorials and docs, but I don't find anything.

P.S.: Sorry, my english is not too good

JamesM · Post by **JamesM** » Thu Feb 21, 2008 6:56 am

<completely shameless plug>

http://www.jamesmolloy.co.uk/tutorial_h ... nitrd.html

</completely shameless plug>

os.hacker64 · Post by **os.hacker64** » Thu Feb 21, 2008 6:57 am

read up and you won't be a dummy.

DeepOS · Post by **DeepOS** » Thu Feb 21, 2008 7:00 am

Thank's guys!!!

James, your link is about VFS, I need real FileSystem (storing the data in a real HD)

AJ · Post by AJ » Thu Feb 21, 2008 8:11 am

Hi,

The VFS provides an abstraction for the on-disk FS, presenting a consistent interface to your OS, whatever disk type and file system you are using.

Have a look on the wiki which has information on several file systems and decide which one(s) you want to implement initially - if you have a decent VFS, you can add support for other file systems modularly or statically, depending on your OS design. James Molloy's tutorial is well worth a read through, so you know what sort of thing you are facing.

Cheers,
Adam

JamesM · Post by **JamesM** » Thu Feb 21, 2008 8:14 am

DeepOS wrote:Thank's guys!!!

James, your link is about VFS, I need real FileSystem (storing the data in a real HD)

Hi,

Apologies - I must have misinterpreted your original post. There is, however, an example on that page of making an initial ramdisk filesystem. That may be of interest to you. Otherwise, the FAT and EXT2 specifications will be useful.

piranha · Post by **piranha** » Thu Feb 21, 2008 9:39 am

SFS is extremely easy the implement: It's a good first filesystem

-JL

zaleschiemilgabriel · Post by **zaleschiemilgabriel** » Thu Feb 21, 2008 9:54 am

Thanks!

Is there any installable file system or a similar application for Windows or Ubuntu for quick access to files on a SimpleFS partition?

DeepOS · Post by **DeepOS** » Thu Feb 21, 2008 4:22 pm

Thanks for all links, I have an idea for developing my own FileSystem, the doc of the VFS helps me a lot

I have a new question, how can I comunicate my OS with the physical drive???

I need to know how can I write/read the physical drive, can anyone give me some info about it?

os.hacker64 · Post by **os.hacker64** » Thu Feb 21, 2008 4:34 pm

Designing a good filesystem is hard, take my word for it.

sam_14332 · Post by **sam_14332** » Thu Feb 21, 2008 4:48 pm

Designing a good filesystem is hard, take my word for it.

Absolutely NOT, implementing a filesystem is something you could do for breakfast. Check out my OS at http://www.mdstud.chalmers.se/~md0samue/ and take a couple of minutes to read the thesis report (the part about the filesystem) - and your filesystem will be up and running in no time!

Combuster · Post by **Combuster** » Thu Feb 21, 2008 5:54 pm

sam_14332 wrote:
Designing a good filesystem is hard, take my word for it.
Absolutely NOT, implementing a filesystem is something you could do for breakfast.

I've popped up your thesis - it goes rambling on a full 7 pages on your filesystem design, and even in the small bit I've read I've got some doubts about wether things will actually work. As far as I can see you did consider a few things, but haven't at all stresstested it on performance. As a master student, I would IMHO expect that you at least give some sort of proof that your FS works that well as you just kindof claimed it does.

Besides, that your lunch came for free isn't really cause that someone else's lunch came for free. I think that a rather large number of people here would not be able to fully understand what's in there.

And given that the review discussions on SFS (which is designed to be the simplest FS) have been far longer and thorough than those 7 pages, I expect that you could spend a thesis on its own really discussing a full-blown FS.

Hence I tend to agree with the (popular) opinion that designing a good FS is really an expert's job. Implementing a complex filesystems is of course a lesser burden, but still not insignificant.

XCHG · Post by **XCHG** » Thu Feb 21, 2008 6:13 pm

sam_14332 wrote:
Designing a good filesystem is hard, take my word for it.
Absolutely NOT, implementing a filesystem is something you could do for breakfast. Check out my OS at http://www.mdstud.chalmers.se/~md0samue/ and take a couple of minutes to read the thesis report (the part about the filesystem) - and your filesystem will be up and running in no time!

Are you serious? You mean you could write a file system such as NTFS in your breakfast time? NTFS is what I call "good" and I call the rest of the file systems including what I have designed, complete crap; that includes all *nix file systems. That's my opinion anyway.

piranha · Post by **piranha** » Thu Feb 21, 2008 6:29 pm

Is there any installable file system or a similar application for Windows or Ubuntu for quick access to files on a SimpleFS partition?

The only available one is for windows, called VDisk.

Absolutely NOT, implementing a filesystem is something you could do for breakfast. Check out my OS at http://www.mdstud.chalmers.se/~md0samue/ and take a couple of minutes to read the thesis report (the part about the filesystem) - and your filesystem will be up and running in no time!

What the ****? I spent 2 hours working on my SFS code, and I am only able to read the index and file entries! You're either very smart and a fast typer or very stupid.

-JL

os.hacker64 · Post by **os.hacker64** » Thu Feb 21, 2008 8:24 pm

Probably stupid, what kind of background do you have that makes you fit to make a "GOOD' filesystem? Breakfast my @$$.