“__aeabi_ldivmod” undefined when compiling kernel module

Question

I\'m trying to compile a kernel module (which I wrote myself) on a raspberry pi. I am compiling it in the target environment.

I get the following output:

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Answer 1

On most 32-bit CPUs, 64-bit division must be implemented with a slow library function. To prevent the compiler from generating unobviously slow code, Linux does not implement these functions.

If you want to do 64-bit divisions, you have to do them explicitly. Use do_div() from <asm/div64.h>.