[Q] Compile modules with preempt mod_unload ARMv7 - Android Q&A, Help & Troubleshooting

I've been trying to compile the nfs module for my generic AML 8726 tablet. My steps have been:
Located and downloaded the kernal source
Set up the Sourcery G++ Lite cross-compiler
Found the .config file for my tablet and did "make meson6smp_android_defconfig" to get the kernel config file
modified the .config file for CONFIG_CROSS_COMPILE, CONFIG_LOCAL_VERSION and set the nfs module to compile
Did "make clean"
Did "make modules"
This produced a nfs.ko module, but it would not load with insmod.
Checking dmesg revealed: "nfs: version magic '3.0.8-g3dd9997-dirty preempt mod_unload ARMv5 ' should be '3.0.8-g3dd9997-dirty SMP preempt mod_unload ARMv7 '"
So everything matched except the cpu architecture.
I then googled around, plus reread the cross-compiler user manual, and figured I needed to set the library to ARMv7-A. I eventually managed that using the linker options to specify the sysroot location.
The module still came out as ARMv5.
Next I tried making the .config file again while setting the library to ARMv7-A ... still ARMv5!!!
So I have to conclude that "preempt mod_unload ARMv5" is being set somewhere else.
I did see one suggestion to add "CONFIG_CPU_V7=y" to the .config file. I tried that, but the compiler just overwrote it during the make.
Can anyone tell me where the %^!&# this is set? Any suggestions would me most appreciated - even ones that don't work out

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I managed to work this out myself eventually. Since I noticed a couple of other similar threads, I'll write a brief howto.
BE WARNED!!! The reason the version magic didn't match is because there was no config.gz on my tablet. I thought I managed to locate the correct .config file, but clearly it wasn't. If you need to fiddle with these settings, you're probably in the same situation.
While I was experimenting, my tablet froze a couple of times, but fortunately was fine when I rebooted, since the modules don't load when rebooted from an insmod.
So, if you're still game, here is what I did.
I assume you already have a kernel source and a cross compiler ready. If not, there's a good guide here.
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Input "make name_of_your_defconfig" in the consonle. Again, you've probably already got this far if you're reading this.
Don't do the edits from Chui's guide to the .config file yet. The menuconfig will override them anyway.
Input "make menuconfig". The following screen appears. Choose "System type" and hit enter.
On the next screen, choose "ARM system type" (the details may differ depending on your architecture).
On the next screen, change the processor. This is where I had to guess a bit, but I also did some research and ARM Ltd. Versatile Express Family" seemed likely. Make your selection, hit enter, and you will return to the previous screen.
Back on the previous screen, select "Versatile Express platform type" and press enter.
In my case, there was only one choice, but it is important to make sure it was selected (use the space bar), otherwise the SMB menu from the next step won't appear.
Exit twice to get back to the main screen, then select "Kernel Features" and press enter.
On the next screen, select "Symmetric Multi-Processing" (using the space bar). If that option is not there, the cpu you selected does not support SMP; you need to select a different processor.
Exit twice, and a dialog box will appear, asking you it you want to save.
Now, you need to make the other changes to the .config file as described in Chui's guide.
Once you're satisfied with the .config file, input "make modules". You may need to answer a question or two during the process.
Open a second console tab, and cd into where your module is. As root, check the version magic string with "modinfo".
Well, that worked for me, and I now have nfs shares mounted on my tablet :victory: Just remember that if you try this, it is at your own risk!!!