How to check the registers value of the network card on ARM Linux?

On our device, we observed that the IPv6 NS packet with multicast address of Layer2 were droped. The tcpdump cannot capture these packet so I guess the packets were dropped by the network card driver(correct me if I am wrong).

To verify this, I want to write a module to check the value of some registers in the network card. Since it开发者_StackOverflow is not possible for me to recompile the original driver I need a separate module to finish this job.

Is it possible to do that? How?

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You can recompile the driver, adding printk with whatever it is you want to see.

If you are developing for an ARM target, it is possible you are using the Embedded Linux Dev Kit (ELDK), so you could look in the kernel source tree for the driver, modify it, and rebuild the kernel. Or you could remove the resident driver and compile it as a loadable module—which is a lot easier for tinkering with a driver.