Compiling a single kernel module

Robotics & Edge Computing Jetson & Embedded Systems Jetson Nano
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1

Hi,

I’m having troubles compiling a single kernel module. I wrote a script to run these commands:

make O=~/build-dir LOCALVERSION="-tegra" tegra_defconfig

make O=~/build-dir LOCALVERSION="-tegra" menuconfig 
# set device driver (TC358743) as a module (=m), I run the following command:

make O=~/build-dir LOCALVERSION="-tegra" modules_prepare

cp /usr/src/linux-headers-4.9.201-tegra-ubuntu18.04_aarch64/kernel-4.9/Module.symvers /home/bsg/build-dir/Module.symvers

make O=~/build-dir LOCALVERSION="-tegra" -j4 --output-sync=target M=drivers/media/i2c modules

Output error:

make[1]: Entering directory '/home/bsg/build-dir'
arch/arm64/Makefile:49: LSE atomics not supported by binutils
make[1]: Leaving directory '/home/bsg/build-dir'
  LD      drivers/media/i2c/soc_camera/built-in.o
  CC      drivers/media/i2c/imx477.o
  CC      drivers/media/i2c/imx219.o
  CC      drivers/media/i2c/imx318.o
  CC      drivers/media/i2c/imx268.o
  CC      drivers/media/i2c/lc898212.o
/home/bsg/kernel/source/public/kernel/nvidia/drivers/media/i2c/lc898212.c: In function ‘lc898212_init’:
/home/bsg/kernel/source/public/kernel/nvidia/drivers/media/i2c/lc898212.c:398:56: error: pointer targets in passing argument 3 of ‘regmap_read’ differ in signedness [-Werror=pointer-sign]
  err |= regmap_read(priv->regmap16, LC898212_ADOFFSET, &data);
                                                        ^
In file included from /home/bsg/kernel/source/public/kernel/nvidia/drivers/media/i2c/lc898212.c:25:0:
/home/bsg/kernel/source/public/kernel/kernel-4.9/include/linux/regmap.h:763:5: note: expected ‘unsigned int *’ but argument is of type ‘int *’
 int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);
     ^~~~~~~~~~~
cc1: all warnings being treated as errors
/home/bsg/kernel/source/public/kernel/kernel-4.9/scripts/Makefile.build:335: recipe for target 'drivers/media/i2c/lc898212.o' failed
make[2]: *** [drivers/media/i2c/lc898212.o] Error 1
make[2]: *** Waiting for unfinished jobs....
  CC      drivers/media/i2c/ov9281.o
  CC      drivers/media/i2c/ov10823.o
  CC      drivers/media/i2c/ov23850.o
In file included from /home/bsg/kernel/source/public/kernel/kernel-4.9/include/linux/trace_seq.h:4:0,
                 from /home/bsg/kernel/source/public/kernel/kernel-4.9/include/linux/trace_events.h:6,
                 from /home/bsg/kernel/source/public/kernel/kernel-4.9/include/trace/trace_events.h:19,
                 from /home/bsg/kernel/source/public/kernel/kernel-4.9/include/trace/define_trace.h:95,
                 from /home/bsg/kernel/source/public/kernel/nvidia/include/trace/events/ov23850.h:45,
                 from /home/bsg/kernel/source/public/kernel/nvidia/drivers/media/i2c/ov23850.c:35:
/home/bsg/kernel/source/public/kernel/kernel-4.9/include/linux/seq_buf.h: In function ‘seq_buf_init’:
/home/bsg/kernel/source/public/kernel/kernel-4.9/include/linux/seq_buf.h:34:12: error: pointer targets in assignment differ in signedness [-Werror=pointer-sign]
  s->buffer = buf;
            ^
cc1: all warnings being treated as errors
/home/bsg/kernel/source/public/kernel/kernel-4.9/scripts/Makefile.build:335: recipe for target 'drivers/media/i2c/ov23850.o' failed
make[2]: *** [drivers/media/i2c/ov23850.o] Error 1
/home/bsg/kernel/source/public/kernel/kernel-4.9/Makefile:1646: recipe for target '_module_drivers/media/i2c' failed
make[1]: *** [_module_drivers/media/i2c] Error 2
Makefile:171: recipe for target 'sub-make' failed
make: *** [sub-make] Error 2

It looks like it’s successful in building some modules but then finds syntax errors in others. This is strange to me because with identical source files I can run:

make O=~/build-dir LOCALVERSION="-tegra" -j4 --output-sync=target modules

and then immediately run

make O=~/build-dir LOCALVERSION="-tegra" -j4 --output-sync=target M=drivers/media/i2c modules

and it builds/compiles all successfully.

What else do I need to add to my script to make this work? What else differs between the make modules and make M=directory?

Thanks
Jamie

3

hello JamieBasil,

please revise your code to address the failure.
according to error reports, all warnings being treated as errors; those compile failures were trigger by this flag, -Werror,
specifically, you’re passing an integer to the function which expect an unsigned variable.

4

Thanks

I find these errors strange because I’m compiling original Nvidia Jetson nano kernel source code that I didn’t modify. This same source code compiles successfully when I build all modules with make O=~/build-dir LOCALVERSION="-tegra" -j4 --output-sync=target modules so this should also compile error free when trying to build modules in a single directory, right?

Another strange thing I noticed is that if I run…

make O=~/build-dir LOCALVERSION="-tegra" -j4 --output-sync=target M=drivers/media/i2c modules

…two times in a row, the first time I get source code errors as I mentioned in first post and then the second time it builds successfully.

make[1]: Entering directory '/home/bsg/build-dir'

  WARNING: Symbol version dump ./Module.symvers
           is missing; modules will have no dependencies and modversions.

make[1]: Leaving directory '/home/bsg/build-dir'
  CC [M]  drivers/media/i2c/imx185_v1.o
  CC [M]  drivers/media/i2c/imx185.o
  CC [M]  drivers/media/i2c/imx274.o
  CC [M]  drivers/media/i2c/tc358743.o
  CC [M]  drivers/media/i2c/ov5693.o
  CC [M]  drivers/media/i2c/tc358840.o
make[1]: Entering directory '/home/bsg/build-dir'
  Building modules, stage 2.
make[1]: Leaving directory '/home/bsg/build-dir'
  MODPOST 6 modules
  CC      drivers/media/i2c/imx185_v1.mod.o
  CC      drivers/media/i2c/ov5693.mod.o
  CC      drivers/media/i2c/imx185.mod.o
  LD [M]  drivers/media/i2c/imx185.ko
  CC      drivers/media/i2c/imx274.mod.o
  LD [M]  drivers/media/i2c/imx185_v1.ko
  LD [M]  drivers/media/i2c/imx274.ko
  LD [M]  drivers/media/i2c/ov5693.ko
  CC      drivers/media/i2c/tc358743.mod.o
  LD [M]  drivers/media/i2c/tc358743.ko
  CC      drivers/media/i2c/tc358840.mod.o
  LD [M]  drivers/media/i2c/tc358840.ko

How is this happening?

Any help appreciated.

Thanks
Jamie

7

hello JamieBasil,

please check Kernel Customization chapter to build the NVIDIA Kernel.
we had validate the process with r32.6.1 public sources, you shall configure toolchain to complete building the sources.

8

I figured it out. I got it to run error free by running make modules.builtin before make modules_prepare

So the order of command execution that runs successfully for me is:

make O=~/build-dir LOCALVERSION="-tegra" modules.builtin
make O=~/build-dir LOCALVERSION="-tegra" modules_prepare
make O=~/build-dir LOCALVERSION="-tegra" -j4 --output-sync=target M=drivers/media/i2c modules
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