It would be really helpful if anyone can help me with how

reg_mprj_datal

and

reg_mprj_datah

are mapped to the user IO's. Also some register definitions found in defs.h seem to be missing in the https://caravel-harness.readthedocs.io/en/latest/gpio.html page or have different addresses as documented.

reg_mprj_datal

(32 bits) is the value of GPIO[31] to GPIO[0], respectively. The bit position matches the GPIO channel. Since there are more than 32 GPIO channels, the rest of them go into another register:

reg_mprj_datah

(32 bits, only the low 6 bits are used) is the value of GPIO[37] to GPIO[32]. Everything above the 6th bit reads zero.

Thank you for the information