Hi Robert
I've added your FAQ to the slightly reorganized developer site (FAQs have their own pages depending on functional area): http://reactos.com/reactos_developer_site/faqs
Cheers Jason
Robert K�pferl wrote:
I finished a new version of the FAQ.
I think it's good enough to be put on the website. Can someone do this? Is there some format that has to be used for ezpublish?
Eric Kohl schrieb:
"Robert K�pferl" rob@koepferl.de wrote:
So is iso9660 available?
Yes!
VFAT = long name extension?
Yes!
UDF?
The filesystem recognizer driver fs_rec.sys recognizes UDF file systems but we don't have a filesystem driver yet.
Regards, Eric
ros-general mailing list ros-general@reactos.com http://reactos.com/mailman/listinfo/ros-general
ROS-Filesystem FAQ
ReactOS uses file system drivers as WinNT does. For that reason it
implements
the IFS-interface which stands for Installable File System.
Therefore it is or
will be able to load and use IFS-drivers. The same as WinNT and
WinXP also uses.
At the time of writing ReactOS was still unable to load WinNT-native
IFS-drivers. But some time, ROS will be able to load even native
NTFS-drivers.
Q: Can we impliment the FreeDos version of the FAT32
filesystem?
A: Reactos supports Fat32 for ages. There's no need to implement
another one.
Q: Does ReactOS support VFAT and long names?A: What are short names? OK. ROS natively supports long and unicode
filenames.
So it's up to the file system driver how it deals with it. The
FAT-driver
delivered with ReactOS supports VFAT (=long names on FAT).
Q: Why don't you implement ext2/3 but messing around with
NTFS?
A: Because NTFS is a major feature which must be supportet at some
time. Ext2/3
is of course a topic for us, however there exist already projects
whose goal it
is to implement Ext2/3 for NT. We will utilize these drivers when
they got good
enough.
Q: Where can I find the Ext2/3-IFS for NT?You can find it here: http://uranus.it.swin.edu.au/~jn/linux/ext2ifs.htm, http://sys.xiloo.com/projects/projects.htm#ext2fsd and http://ashedel.chat.ru/ext2fsnt/
Q: Can I help programming installable file system drivers?A: Yes, there's lots of work to do around IFS-drivers. It's however
very hard to
program. I like to say that programming dirvers is hard but
programming file
system dirvers is the king's discipline. If you are a real kernel
hacker, come
to our maling list and anounce yourself.
Q: Can we use ext2/3 instead of poking around in NTFSA: Yes, it's up to you, which file system you want to use. For now
however
neither the ext2/3-IFS nor the our NTFS-IFS is ready to use for read
and write.
So there's still lots of work to do and so the only option is the
FAT-IFS.
Q: Why do you not make use of the Linux-NTFS project's
sources?
A: These sources are rather ok, but as all NFTS implementations (but
the one
from MS) it lacks writing support. And there are still big areas of
NTFS wich
are undocumented/unknown. We are working together with them or just
using their
code. In the moment ther's however not that priority for NTFS. So
it's still
sleeping.
Q: I would vote for reiserfs as the standard FS for ReacOSA: Good Idea. However there's no ReiserFS driver for NT/ROS
available. You are
welcome to program one. I think in the last time there apeared one
in the net.
Q: How critical is NTFS support is for ReactOS to be
successful?
A: ReactOS will eventually want NTFS support, but for now, there is
no critical
reason to have it. NTFS is primarily a hard disk filesystem, so the
only reason
one would absolutely need it would be if you wanted to access an
NTFS-formatted
physical partition on a hard disk installed in a ReactOS computer. Other file systems will be able to provide the advanced features of
NTFS
(journaling, ACLs, compression, hard links, etc.) if strict NTFS
compatibility
is not a requirement. All software comes on CD or DVD media
(ISO-9660 or UDFS),
or possibly on floppies (FAT). External media (compact flash, memory
sticks,
etc.) tend to be formatted FAT.
Q: The JFS-sources (also for OS/2) are free to download. Why
not make JFS
the standard FS in ROS?A: Yes, at least an IFS is already planned. Since JFS is still a
state of the
art file system with journalling, big file+partition sizes ACLs and
extended
attributes and hard links, it would well suite ROS. We are working
on it but you
are welcome to help.
Q: How do you deal with case sesitivity (i.e. ext2) ?A: Case sensitivity is not a problem of the file system itself. It's
an aspect
of the corresponding dirver. The object manager which provides the
whole
namespace supports case sensitivity natively. So IFS-drivers get a
special case
flag which they must handle accordingly. A ported file system
diriver must
therefore be able to handle both, case (in)sensitivity.
Q: Does a 64-bit file system run on a 32-bit machine?A: Yes. The 64-bit are just the adressing on the disk. It has
nothing to do with
the executable which contains the driver. That executable hat that
manny bits as
the whole operating system has.
Q: What file systems does ReactOS support, now?A: For now, the only file system supported is FAT(12/16/32) without
VFAT.
Q: What file systems will ReactOS support?A: Our goal is to support as many file systems as possible. There
can be
developed IFS-drivers for at least these disk file systems which are
available
with linux. It's however verry hard to program a compliant/working
file system
driver. So it will take some time. At least there will be:
FAT(12/16/32) plus VFAT
ISO-9660 - CD-ROM
one Higher FS like ext3, NTFS or JFS
NPFS - named pipe file system (internal FS)
MSFS - mailslot file system (internal FS)
Q: I have an idea: Why not throw away these odd drive letters?
A: Old Idea. I'd say that also MS has had this idea. But they didn't
realize it
up to now. Why? In the ROS-team there are also thinkings about this
issue. But
up to now there has not been a sufficient conclusion about this
topic. Maybe MS
is also still thinking. There are Ideas as having a memory based mount file system or
uncovering the
object managers name space to win32-apps or drive words. Everything
brings
disadvantages with it. By the way: The ROS/NT-Kernel doesn't work with drive letters. These
are a
relict of DOS (or should I say CP/M) in win32.
Q: What is a Redirector?A: This is a special form of an IFS driver. It doesn't implement a
on disk file
system. Instead it relies on the kernel's network stack and provides
most times
a remote file system (i.e. SMB-Shares).
Q: What is a file system recognizer?A: A real file system driver is a heavy wight. Loading it just for
it to see
that there is no partition it could mount is waste. For this reason
Dave
invented so called recognizer driver. They are more less integral
part of the
driver architecture. Such a little driver gets loaded and searches
partitions
for file systems it's companion IFS is capable of. If it finds such
a partition
it loads it's companion IFS to mount it.
*SEH-Problem*: Structured exception handling (SEH) is used in
programming
ReactOS as it is used in programming for OS/2 or WinNT, too. SEH is
a game wich
is played between OS and Compiler (Keywords: __try, __except,
__finally).
ReactOS itself is SEH-aware and provides the infrastructure, however
up to now,
the used GNU-compiler is not capable of generating SEH aware code.
So one can't
compile a driver or program which uses SEH with the GNU-Compiler.
� 2/2004 Robert K�pferl <>
ros-general mailing list ros-general@reactos.com http://reactos.com/mailman/listinfo/ros-general
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Jason Filby