[HOWTO] Compile modules for stock kernels - Galaxy S II Original Android Development

I couldn't figure out how to compile a module for stock kernel - I kept getting the following in dmesg:
Code:
<module>: disagrees about version of symbol module_layout
I sent a message to Samsung Open Source Release Center on Friday and received a very helpful response yesterday. Basically, c1_rev02_defconfig contains some debug options that are not set in the actual kernel. These are the options that should not be set in the config:
Code:
CONFIG_DEBUG_PREEMPT
CONFIG_DEBUG_RT_MUTEXES
CONFIG_DEBUG_SPINLOCK
CONFIG_DEBUG_MUTEXES
CONFIG_PROFILING
CONFIG_PERF_EVENTS
CONFIG_PERF_COUNTERS
CONFIG_LATENCYTOP
CONFIG_FTRACE
You can use the attached script to modify all these values (the script was also supplied by Samsung, although it was syntactically incorrect and a couple of modifications were necessary to make it work). I have included a copy of the c1_rev02_defconfig with these modifications.
Using this config, I was finally able to compile modules that can actually be loaded on the device
Kudos to Samsung for sending me this information.

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Nice info I guess that will help out the people who had issues with kernel modules on stock ROMs...

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jps1974 said:
Kudos to Samsung for sending me this information.
Click to expand...
Click to collapse
No, that is the stuff they should put on their server. Makes you wonder what else they haven't released. Every time they make modifications to the GPL open source code (eg. kernel) and release a new version, they must release the code, and the exact same files they used to build it.

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Thanks
That was the info I missed. I have successfully compiled cifs for kf1.
Sent from my GT-I9100 using XDA App

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You know guys if there is a basic tutorial available online?.
Thank you!

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Hi, I am new to compile modules for android (new to compile kernel anyway)
thanks for your info and config, I am now able to compile modules.
I had a problem on the compiled modules tho, wonder can anyone please point me some direction?
when I insmod the ko, dmesg gives me:
xyz.ko : no symbol version for module_layout
Any hint?
more info, I am compiling like:
I am aiming on compiling to for stock ROM, uname -r > 2.6.35.7-I9100XWKDD-CL161513
- I read, and follow base on http://forum.xda-developers.com/showthread.php?t=1113191
- kernel source from: SHW-M250L kernel source from OSRC, https://opensource.samsung.com/
- .config file of this post, select my wanted modules using make menuconfig
- then make ARCH=arm CROSS_COMPILE=__MYPATH__/bin/arm-none-eabi- modules
Thanks!

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Hi,
I'm using insecure kernel :
Code:
#uname -r
2.6.35.7-I9100XWKE2-CL187606
I cross compiled modules using your config file but each time I'm trying to insmod it, I have: failed (Exec format error)
and busybox insmod gives me a invalid module format error
I use the commands :
Code:
make ARCH=arm CROSS_COMPILE=/opt/toolchains/arm-2009q3/bin/arm-none-linux-gnueabi- menuconfig
make ARCH=arm CROSS_COMPILE=/opt/toolchains/arm-2009q3/bin/arm-none-linux-gnueabi- modules
So I don't really know where I'm wrong here

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alx5962 said:
Hi,
I'm using insecure kernel :
Code:
#uname -r
2.6.35.7-I9100XWKE2-CL187606
I cross compiled modules using your config file but each time I'm trying to insmod it, I have: failed (Exec format error)
and busybox insmod gives me a invalid module format error
I use the commands :
Code:
make ARCH=arm CROSS_COMPILE=/opt/toolchains/arm-2009q3/bin/arm-none-linux-gnueabi- menuconfig
make ARCH=arm CROSS_COMPILE=/opt/toolchains/arm-2009q3/bin/arm-none-linux-gnueabi- modules
So I don't really know where I'm wrong here
Click to expand...
Click to collapse
can you do a dmesg here?
I "think" I am on a same boat as you are on the error tho.....

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I didn't checked dmesg, shame on me !
so the error is :
joydev: no symbol version for module_layout
I used your config file, do I need to fix config each time I update with menuconfig ?

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alx5962 said:
I didn't checked dmesg, shame on me !
so the error is :
joydev: no symbol version for module_layout
I used your config file, do I need to fix config each time I update with menuconfig ?
Click to expand...
Click to collapse
dmesg is good to read, we are both compiling the same module (joydev)
the config file is not from me, is from jps1974.
no I don't think you need to fix unless you uses the build_kernel.sh unmod, since it cp the defconfig everytime, still I face the same problem...

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Instead of SHW-M250L kernel source from OSRC, I just did a quick change to GT-I9100_HK_Opensource.zip
A little bit different on the package, but still the same work flow and results...
.config file:
cp ~/sgs2/9100i_hk/arch/arm/configs/c1_rev02_defconfig ~/sgs2/9100i_hk/kernel/.config
./fix_config.sh
make ARCH=arm CROSS_COMPILE=[PATH_TO_G++LITE_BIN] modules
compile without problem, but no luck, insmod still report:
insmod: init_module '/lib/modules/joydev.ko' failed (Exec format error)
dmesg | grep joy report:
joydev: no symbol version for module_layout
Any help, any directions?
Thanks in advance!!!

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I used the european I9100 source from the samsung site and the config file from the opening post when I successfully compiled my modules.
Sent from my GT-I9100 using XDA App

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richyy74 said:
I used the european I9100 source from the samsung site and the config file from the opening post when I successfully compiled my modules.
Sent from my GT-I9100 using XDA App
Click to expand...
Click to collapse
YES SIR, will do try this src next!!!!!
richyy74 would u mind share with us which kernel are you at on your phone?
and which version of toolchain u are using on the compile?
Thanks.

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A bit of update, just try with GT-I9100_Opensource.zip, nope, still no luck........
I start to think would that be problem of toolchain (which in the readme of the zip from Samsung, they are using 2009q3 while I am using the current 2011 build), or it is possible problem because my/our unsecure kernel (2.6.35.7-I9100XWKDD-CL161513)...

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update: Roll back on 2009q3, nope, no luck.............
I can only thinks that it is due to the kernel I am using.............

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I compiled for ke7 and kf1 cifs, slow-work and cpu governor modules.
I used the 2009 gnu/linux toolchain from codesourcery /it ends with 67 something/
I never succeded with the version mentioned in the readme.
Sent from my GT-I9100 using XDA App

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richyy74 said:
I compiled for ke7 and kf1 cifs, slow-work and cpu governor modules.
I used the 2009 gnu/linux toolchain from codesourcery /it ends with 67 something/
I never succeded with the version mentioned in the readme.
Sent from my GT-I9100 using XDA App
Click to expand...
Click to collapse
Thanks for your direction, will do more test after my "should have slept" 5 hours session.... which end up in data center instead of bed...

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utp said:
Thanks for your direction, will do more test after my "should have slept" 5 hours session.... which end up in data center instead of bed...
Click to expand...
Click to collapse
The "exec format error" means that you compiled it for the wrong architecture.
To see which arch the kernel module was compiled for, use the "file" command (found on any Linux computer but not present on the phone itself).
The file command is an extremely useful function for identifying files.
So, at a terminal, type:
Code:
file -k /user/home/output/example.ko
It should output information on the file, which will clarify whether it was statically built, which architecture, etc. Examples:
Dynamically linked executable:
Code:
"ELF 32-bit LSB executable, ARM, version 1 (SYSV), dynamically linked (uses shared libs), not stripped"
Statically linked executable:
Code:
"ELF 32-bit LSB executable, ARM, version 1 (SYSV), statically linked, stripped"
Object file:
Code:
"ELF 32-bit LSB relocatable, ARM, version 1 (SYSV), not stripped"
Most importantly, if it doesn't say 32bit ARM, it will not work.

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So the module I cross-compiled gives me :
joydev.ko: ELF 32-bit LSB relocatable, ARM, version 1 (SYSV), not stripped.
So it was correctly compiled, I may need to try another toolchain.

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Using Sourcery G++ Lite 2009q3-68 for ARM EABI toolchain, still have the issue.
So as I use an insecure kernel, I may need to ask the author what compiler he used for it.