How to build the KMI ABI test kernel module, kmi_sym.ko
- Set up the GKI source.
Set up and export GKI_DIR to be used for kernel module building
$ cd $GKI_DIR
$ repo init -u https://android.googlesource.com/kernel/manifest
-b common-android12-5.10
$ repo sync
See "GKI Monthly Branch Handbook" for details.
- Build arm64 GKI under $GKI_DIR
$ BUILD_CONFIG=common/build.config.gki.aarch64 build/build.sh -j16
- Download a supported kernel symbol file, vmlinux.symvers, from GKI AB:
$ export GKI_BID=7618735
https://ci.android.com/builds/submitted/$GKI_BID/kernel_aarch64/latest
$ cp vmlinux.symvers $ANDROID_BUILD_TOP/development/gki/kmi_abi_chk/vmlinux.symvers-$GKI_BID
- Replace the Module.symvers just built with the supported kernel symbol file.
$ cp vmlinux.symvers $GKI_DIR/out/android12-5.10/common/Module.symvers
- Create the KMI symbol list include file:
$ cd development/gki/kmi_abi_chk
$ cp $GKI_DIR/out/android12-5.10/common/Module.symvers vmlinux.symvers-$GKI_BID
$ awk '{printf("\t.xword\t%s\n",$2)}' vmlinux.symvers-$GKI_BID >> kmi_sym_list-$GKI_BID.inc
Note that kmi_sym_list-7618735.inc included in the current directory is a
version modified from the one based on vmlinux.symvers of build 7618735, the
initial GKI 5.10 released in July, 2021. Search b/197035344 for details.
- Build the kernel module
$ make ARCH=arm64 CROSS_COMPILE=aarch64 LLVM=1 LLVM_IAS=1 LTO=thin
A few prebuilt test kernel modules, kmi_sym-*.ko, for arm64 GKI 5.10
2021-07 and later builds is included under prebuilts/ directory.
How to use/run KMI test kernel module, kmi_sym.ko, on GKI
- Copy the test kernel module to the Android device
$ adb push kmi_sym.ko /data/local/tmp
- "Root" the Android device we'd like to run the test
$ adb root
- Check the kernel information on the device
emulator64_arm64:/ # uname -a
Linux localhost 5.10.43-android12-9-00005-g376ecc372342-ab7614753#1 SMP PREEMPT Thu Aug 5 15:12:49 UTC 2021 aarch64
- Load the test kernel module
emulator64_arm64:/ # lsmod | grep kmi_sym
emulator64_arm64:/ # insmod /data/local/tmp/kmi_sym.ko; echo $?
0
- Verify the test kernel module is loaded successfully
emulator64_arm64:/ # lsmod | grep kmi_sym
kmi_sym 57344 0
emulator64_arm64:/ # dmesg | grep KMI
[ 1669.833480] 5317 KMI ABI symbols at 00000000d34c59ea
- Unload the test kernel module
emulator64_arm64:/ # rmmod kmi_sym; echo $?
0
emulator64_arm64:/ # dmesg | grep KMI
[ 1669.833480] 5317 KMI ABI symbols at 00000000d34c59ea
[ 1860.571944] Cleaning up KMI ABI.