Dear sir/madam

I have following queries regarding implementation of MBED CRYPTO Libraries :

1) How crypto libraries files could be used on baremetal with no entropy source(cross compilation )?

2) How asymmetric cryptographic operations  like RSA , RNG , EC ,DSA etc , could be implemented on baremetal without entropy , seed provisions ?

3) If i want to use some custom PRNG and entropy , then how the respective contexts structures could be filled ?