Unknown symbol camera_common_parse_ports

Autonomous Machines Jetson & Embedded Systems Jetson TX1
1

Hello,

I built a module based on kernel_source/drivers/media/i2c/ov5693.c but when I try to insert it into the TX1 I get unknown symbol errors from camera_common. How do I get those symbols?

Unknown symbol camera_common_parse_ports (err 0)
Unknown symbol camera_common_parse_clocks (err 0)
2

refer

/kernel/drivers/media/platform/tegra/camera/camera_common.c

i did try module build ov5693.c but fail dependency

3

Right, i’m including that in the module. But that file doesn’t seem to export its own symbols. Not sure how to get around it.

4

Did you build it as loader module by modify the Makefile to obj-m ?
Please reference to https://www.kernel.org/doc/Documentation/kbuild/makefiles.txt

— 3.3 Loadable module goals - obj-m

$(obj-m) specifies object files which are built as loadable
kernel modules.

A module may be built from one source file or several source
files. In the case of one source file, the kbuild makefile
simply adds the file to $(obj-m).

Example:
	#drivers/isdn/i4l/Makefile
	obj-$(CONFIG_ISDN_PPP_BSDCOMP) += isdn_bsdcomp.o

Note: In this example $(CONFIG_ISDN_PPP_BSDCOMP) evaluates to 'm'

If a kernel module is built from several source files, you specify
that you want to build a module in the same way as above; however,
kbuild needs to know which object files you want to build your
module from, so you have to tell it by setting a $(<module_name>-y)
variable.

Example:
	#drivers/isdn/i4l/Makefile
	obj-$(CONFIG_ISDN_I4L) += isdn.o
	isdn-y := isdn_net_lib.o isdn_v110.o isdn_common.o
5

Yes, I do build it as a module. I believe that’s where the problem is.

According to this: [url]https://www.linux.com/learn/kernel-newbie-corner-kernel-symbols-whats-available-your-module-what-isnt[/url] loadable modules only have access to the symbols that are explicitly exported using “EXPORT_SYMBOL().” Not sure there’s any way around it besides modifying camera_common.c to export those symbols and recompiling the kernel.

I’ll keep messing with it.

6

The easy way is copy that easy function to this driver. That function only to parser the device tree to get information.