Linux Partition support

Ref: Max storage size and types and post

any prospect of being able to use something like ext3 or ext4?

I switch between Linux and RISC OS so it would be great if I could access the linux partition of the attached drive from RISC OS.

Linux kernel support for ADFS may have been dropped, but it did support new disc formats ISTR.

Last tweak was one I did in 2011 to add filetype suffix support and better resolution of timestamps for transfer to ext4.

Ah, it was you :) Thanks for those kernel changes, they have come in rather handy when I found them (kernel 3.0 and later).

Last time I looked at it, the ‘experimental’ write support was lacking code to manipulate the free space map. So while you could overwrite files with new contents, you couldn’t make them longer or shorter, or create new files. That limits its usefulness. But the support for reading was fairly decent.

I can’t take credit for any of the rest of it!

But yes, the reading support was very useful.

JFYI Linux Kernel still has support for ADFS, but it has to be configured before building the Kernel source.

It’s no longer configured by default. Also not sure it can write ADFS, however it should read ADFS fine AFAIR.

There is a BSD-licensed ext4 library, but I looking at “Supported ext2/3/4 features”, I don’t know whether a desktop Linux partition uses any of the incompatible features or not?

Hey Julie,
so lwext4 has full support for ext2 and only partial support for ext3 and ext4. However is an excellent starting point to add support for EXT to RISC OS via RISC OS FileSystems.

lwext4 has only standard C dependencies AFAIR (maybe something else on Windows) so it should compile straight away in GCCSDK and it should be easy to build under DDE. Obviously it needs the RISCOS addition to the devblock section and in few other places as well as add the support for FileCore API to be used directly.

Actually this reminds me that HelenOS could be a potential candidate to look into a kernel replacement for RISC OS, but this type of things requires time :( (the connection I made is not crazy lol HelenOS is where lwext4 comes from IIRK)

I have some vague memory of was something in the dim distant past that would read ext2 partitions on a RiscPC. Maybe it was part of ArmLinux?

IscaFS.

http://splodge.fluff.org/~phil/risc-os/index.html