How to use my custom Shared object(.so) file in Koreader

[Maimun Ahmed]

Hi there guys. I wanted to use my custom .so file in koreader. Is there any way I can achieve it. I tried putting the file inside of "koreader\base\build\x86_64-linux-gnu-debug\libs" and that works, but just in development.

When I try to put into the file to the libs folder of the actual release version that is installed into my kindle it doesn't work.

Note: I included ffi.load to get the .so file.

Here is an extract of how I am trying to use it (actual code is not in this exact sequence):

local example = ffi.load("libexample.so")
ffi.cdef("void hello();")

example.hello()

I am unable to describe the terms accurately so i attached the links for reference.

Anyone for help please.

[Maimun Ahmed]

Am I putting the file under wrong directory?

[Frenzie]

When you say "the file," do you mean the exact same file in both cases?

By which I mean the file should be different for amd64 vs arm.

[Maimun Ahmed]

Yeah, the same .so file. Firstly, I built the .so file with Golang selecting the OS as linux and architecture as 32 bit/386 (was getting an error in the emulator that 64 bit .so file is not supported).

Everything works fine in the emulator, the .so works exactly as expected but, my kindle says something like:

Failed to load dynamic library libs/libexample.so. No such file or directory.

As mentioned in the setupkoenv.lua, i am putting the file in the libs folder.

[Frenzie]

Kindle requires an ARM 32-bit build.

I don't know Go, but a quick check locally shows:

go tool dist list | grep linux
linux/386
linux/amd64
linux/arm
linux/arm64
linux/loong64
linux/mips
linux/mips64
linux/mips64le
linux/mipsle
linux/ppc64
linux/ppc64le
linux/riscv64
linux/s390x

The only one that might work is arm.

[Maimun Ahmed]

Originally Posted by Frenzie

Kindle requires an ARM 32-bit build.

Thanks brother. It indeed solved the problem. Building the .so file for arm completely solves the problem. I wonder why the error message was so misdirecting.