Failure to compile for FP256BN

[cjpn]

When I try to build the new version of the library (master branch) with FP256BN as one of the curves it fails because config_curve_FP256BN.h doesn't have ATE_BITS_FP256BN set correctly. It seems that one of the parameters (AB) for FP256BN in the file cmake/AMCLParameters.cmake is missing, it is set to '.' .

How do I fix this? What value is needed for ATE_BITS_FP256BN (AB in the cmake/AMCLParameters.cmake file)?

I know that this curve has reduced security, but it is used by the Trusted Platform Module (TPM). The other pairing friendly curve used by the TPM FP638BN is not included at all.