[Buildroot] [PATCH v2 2/2] axfs: add new filesystem type

[Ariel D'Alessandro]

Yann,

El 13/10/15 a las 17:53, Yann E. MORIN escribió:
> Arnout, Ariel, All,
> 
> On 2015-10-05 19:53 +0100, Arnout Vandecappelle spake thusly:
>> On 05-10-15 17:55, Ariel D'Alessandro wrote:
>>> The Advanced XIP File System is a Linux kernel filesystem driver that enables
>>> files to be executed directly from flash or ROM memory rather than being copied
>>> into RAM.
> [--SNIP--]
>>  It would be nice to add the axfs kernel side as a kernel extension as well. But
>> that looks heavily non-trivial.
> 
> I had a quick and cursory look at the axfs sources, and I think this
> could be quite easily achievable. Non-trivial, granted, but not too
> complex either.
> 
> Ariel, are you interested in adding this as a kernel extension?
> (Hint: it would be really great! ;-) )

Yes, I'll make some room and take a look at this!

> 
> Kernel extensions are a way to "modify" the kernel source tree with
> patches provided by another package:
>     http://buildroot.org/downloads/manual/manual.html#linux-kernel-ext
> 
> Basically, here's what you'd have to do in the axfs extension:
> 
>   - get the 'raw' version of the kernel with (but see notes below):
>         AXFSUTILS_KVER = $(MAKE) -C $(LINUX_DIR) kernelversion
> 
>   - check that there is a patch directory for that kernel version:
>         kernel/patches/v$(AXFSUTILS_KVER)/
>     => if not, bail out
>     => if yes, continue
> 
>   - copy $(@D)/kernel/fs/axfs to $(LINUX_DIR)/fs/axfs
> 
>   - copy $(@D)/include/linux/* to $(LINUX_DIR)/include/linux/
> 
>   - modify $(LINUX_DIR)/fs/Kconfig with (before last line):
>         source "fs/axfs/Kconfig"
> 
>   - modify $(LINUX_DIR)/fs/Makefile with (as last line):
>         obj-$(CONFIG_AXFS) += axfs
> 
> Obviously, entirely untested; adapt to Real Life (TM). ;-)
> 
> Notes: ideally, the kernel 'raw' version should be provided by
> linux/linux.mk but we currently do not have it yet; we only have
> 'kernelrelease', not 'kernelversion'. It would be interesting if you
> provided an initial patch that adds this.
> 
> Currently, 'kernelrelease' is in $(LINUX_VERSION_PROBED), so maybe you
> could introduce LINUX_VERSION_RAW filled with the output of
> 'kernelversion' (see how it's done for 'kernelrelease').

That's pretty clarifying! Thank you very much for this Yann, it will
help me a lot. I'll try to submit patches for this ASAP.

Thanks,

-- 
Ariel D'Alessandro, VanguardiaSur
www.vanguardiasur.com.ar