[fedora-arm] Compiling in FC22

[Robert Brown]

Hi

On 15/03/15 05:18, Niels de Vos wrote:
> On 2015-03-13 19:19, Robert Brown wrote:
>> Hi
>> I am trying to compile a module for FC22 Rawhide on an A10 device
>> (MK802ii) with a uname -r of 3.19.0-0.rc7.git3.1.fc22.armv7hl but am
>> getting a truncated vermagic: vermagic:       3.19.0-rc7 SMP
>> mod_unload ARMv7 p2v8
>> The .config I am using is a copy of the
>> /boot/config-3.19.0-0.rc7.git3.1.fc22.armv7hl.
>> I have tried editing LOCALVERSION without success.
>>
>> If I edit the Makefile from the rpmbuild process to:
>> SUBLEVEL = 0-0
>> EXTRAVERSION = rc7.git3.1.fc22.armv7hl
>> or to
>> SUBLEVEL = 0
>> EXTRAVERSION = -0.rc7.git3.1.fc22.armv7hl
>> I still only get vermagic:       3.19.0-0.rc7 SMP mod_unload ARMv7 p2v8
>>
>> The version.h file generated in include/generated/uapi/linux/
>> says #define LINUX_VERSION_CODE 201472
>> whereas the one in /usr/include/linux/version.h says
>> #define LINUX_VERSION_CODE 201728
>>
>> Any tips on where to go with this?
>
> This is actually the same for arm or any other Fedora kernel. You will 
> need to
> have the kernel-devel package installed for the kernel that you want 
> to compile
> the module for. And, after that, you can find the sources of your 
> module and
> build only the module for that kernel with:
>
>     $ make -C /lib/modules/$(uname -r)/build M=$PWD/fs/fuse/
>
> The above would (try to) compile the fuse.ko module for the current 
> running
> kernel. 
Thanks that's helpful for just compiling the one module.
> The current working directory would be a (git) repository where the
> sources/branch is available.
>
> In case the kernel module that you want to compile needs extra .config 
> options
> (that do not affect the rest of the kernel/modules), you should be 
> able to pass
> them on the 'make' command line:
>
>     $ make -C .... EXTRA_CFLAGS="-DCONFIG_SOME_DRIVER=m" M=...
I decided to try cross-compiling as I figured it would be far quicker on 
the laptop than on the device. I used the same .config, Makefile and 
kernel sources but had no success getting the required vermagic until I put
CONFIG_LOCALVERSION="-0.rc7.git3.1.fc22.armv7hl"
into the .config file and set
SUBLEVEL = 0
EXTRAVERSION =
in the Makefile. This gave me the desired result.
So, encouraged, I tried again on the device (i.e. not cross compiling) 
but again no good.
Decided to delete the file Module.symvers so it would re-build on the 
next run and straight away I had success.
Is this documented?
Went on to compile the r8188eu from github as suggested by Clive Messer 
as the Staging version was buggy.  So far so good.

Thanks

>
> HTH,
> Niels
>