Using VHPIDIRECT with shared libraries like openSSL

[tmeissner]

Hi everyone. I want to set up a cosimulation of crypto units with openSSL as reference model. I try to recycle parts of older code of cosimulation with GHDL, so the C-part is already there. I have a question of how to use the shared library with nvc.

ATM I have something like that:

$ cc -shared -fPIC -lcrypto -libssl aes_ref.c -o aes_ref.so
$ nvc --load=aes_ref.so tb_aes

What I get is an error with a symbol which cannot be found:

** Note: loading VHPI plugin tb_aes.so
/opt/nvc/bin/nvc: symbol lookup error: /home/torsten/aes/aes.so: undefined symbol: EVP_EncryptUpdate

So, my question is, how could I give nvc the information where the openSSL libraries are on my machine? With GHDL, I do it at elaboration:

$ ghdl -e --Wl,tb_aes.c -Wl,-lcrypto -Wl,-lssl tb_aes

[nickg]

Try putting the libraries after the source file (like you have in the GHDL example) as the linker only searches for unresolved symbols in libraries listed after the object file in the linker command line:

$ cc -shared -fPIC aes_ref.c -o aes_ref.so -lcrypto -lssl

If you run ldd aes_ref.so you should see it linked against libcrypto.so.

[tmeissner]

Thanks, this works 🤓