[ECOS] DOS filing system

[ECOS] DOS filing system

[David Williams]

Hi all,

I am new to eCos,

I am considering using it on a Power PC (MPC850) with a PCMCIA and compact 
flash ATA cards. I would like to write to the cards in DOS format and was 
hopping there is support for a DOS filing system. I see from the news that 
there is support for PCMCIA and there is also a filing system. What I want 
to do is write to ATA flash cards (PCMCIA and compact flash) from eCos in 
DOS format.

Is this supported already? If not what parts do I need to write myself?

TIA
Dave.

Re: [ECOS] DOS filing system

[Lewin A.R.W. Edwards]

Hi David,

>hopping there is support for a DOS filing system. I see from the news that
>there is support for PCMCIA and there is also a filing system. What I want
>to do is write to ATA flash cards (PCMCIA and compact flash) from eCos in
>DOS format.

Unfortunately while several people including myself have developed DOS 
filesystems that run under eCos, licensing problems preclude us from 
releasing the source to the eCos community at this time.

So you'll need to do most of the work to get a DOS filesystem running. eCos 
handles the mechanics of routing application calls into your filesystem, 
but you need to do all the disk-banging yourself. (The good news is that 
FAT12/16/32 are all pretty easy to support, especially if you don't support 
the special cases for FAT32. Figure about 2-3 weeks of development time).

=== Lewin A.R.W. Edwards (Embedded Engineer)
Work: http://www.digi-frame.com/
Personal: http://www.zws.com/ and http://www.larwe.com/

"Und setzet ihr nicht das Leben ein,
Nie wird euch das Leben gewonnen sein."

Re: [ECOS] DOS filing system

[Lewin A.R.W. Edwards]

Hello Wilson,

> > but you need to do all the disk-banging yourself. (The good news is that
> > FAT12/16/32 are all pretty easy to support, especially if you don't
>
>Do you have any good resources as a starting point for FAT16 and FAT32?

I will be happy to give you (or any other list members) my collated 
"research materials" on FAT12 and FAT16; it's all you really need to 
implement the FSs. I'm not sure that I can give you my document on FAT32, 
as it is labeled "Microsoft Company Confidential"; I'll check on it (the 
document may have been released publicly since I received it a couple of 
years ago!). However I am leaving Thursday morning for a conference and I'm 
rather busy until then. Do you mind waiting until the weekend (Monday at 
latest)?

David, would you like to be copied on that?

=== Lewin A.R.W. Edwards (Embedded Engineer)
Work: http://www.digi-frame.com/
Personal: http://www.zws.com/ and http://www.larwe.com/

"Und setzet ihr nicht das Leben ein,
Nie wird euch das Leben gewonnen sein."

Re: [ECOS] DOS filing system

[Wilson Kwan]

Hi Lewin,

> Hello Wilson,
>
> I will be happy to give you (or any other list members) my collated
> "research materials" on FAT12 and FAT16; it's all you really need to
> implement the FSs. I'm not sure that I can give you my document on FAT32,
> as it is labeled "Microsoft Company Confidential"; I'll check on it (the
> document may have been released publicly since I received it a couple of
> years ago!). However I am leaving Thursday morning for a conference and
I'm
> rather busy until then. Do you mind waiting until the weekend (Monday at
> latest)?
>
> David, would you like to be copied on that?

That would be great. Since I'm the lead architect/developer on our eCos
implementation I'll see what I can do about contributing my FAT16 work back
to the eCos community. I'm sure a few people might like that. :) I won't be
starting on any file system work for a couple of weeks so after your
conference would be great.

Thanks again,

Wilson

Re: [ECOS] DOS filing system

[Lewin A.R.W. Edwards]

Hi Wilson (et al .. :)

> > I will be happy to give you (or any other list members) my collated
> > "research materials" on FAT12 and FAT16; it's all you really need to
> > implement the FSs. I'm not sure that I can give you my document on FAT32,
>
>That would be great. Since I'm the lead architect/developer on our eCos
>implementation I'll see what I can do about contributing my FAT16 work back
>to the eCos community. I'm sure a few people might like that. :) I won't be

It would be really great if you could do that. In fact I would love to roll 
our code into the public domain, but honestly I don't feel up to fighting 
the necessary legal tussle to convince our people.

I did briefly consider redeveloping a FAT filesystem at home using drive 
image files and stdio to simulate the underlying block driver, but I 
decided that it is in too much of a gray area ethically. (Besides, who the 
heck has time to work out of hours? I haven't been able to do a personal 
project for years...)

I'll be happy to contribute any help short of actually writing your code, 
too. My FS code is about a year and a half old now, and pretty thoroughly 
debugged.

=== Lewin A.R.W. Edwards (Embedded Engineer)
Work: http://www.digi-frame.com/
Personal: http://www.zws.com/ and http://www.larwe.com/

"Und setzet ihr nicht das Leben ein,
Nie wird euch das Leben gewonnen sein."

Re: [ECOS] DOS filing system

[Matthew H. Gerlach]

I believe the FreeDOS project might be a good place for information on the DOS
file system.  Obviously there is dos file system code, and I notice there is a
recent fdisk program.

http://www.freedos.org



"Lewin A.R.W. Edwards" wrote:

> Hello Wilson,
>
> > > but you need to do all the disk-banging yourself. (The good news is that
> > > FAT12/16/32 are all pretty easy to support, especially if you don't
> >
> >Do you have any good resources as a starting point for FAT16 and FAT32?
>
> I will be happy to give you (or any other list members) my collated
> "research materials" on FAT12 and FAT16; it's all you really need to
> implement the FSs. I'm not sure that I can give you my document on FAT32,
> as it is labeled "Microsoft Company Confidential"; I'll check on it (the
> document may have been released publicly since I received it a couple of
> years ago!). However I am leaving Thursday morning for a conference and I'm
> rather busy until then. Do you mind waiting until the weekend (Monday at
> latest)?
>
> David, would you like to be copied on that?
>
> === Lewin A.R.W. Edwards (Embedded Engineer)
> Work: http://www.digi-frame.com/
> Personal: http://www.zws.com/ and http://www.larwe.com/
>
> "Und setzet ihr nicht das Leben ein,
> Nie wird euch das Leben gewonnen sein."