SceMsif

Certainly means Memory stick interface.

sceMsifInitializeMmcDeviceForDriver
Part of functionality is same as msif_get_sha224_digest_source.

msif_get_time_from_SceMsifSmshc
Returns wide time difference from last SceMsifSmshc interrupt.

sceMsifDevNullPrepareDmaTableForDriver
Writes some data to the memory card. Data is taken from memblock2.

msif_get_sha224_digest_source
Gets data that is used to calculate sha224 digest. This digest is used to verify static table of sha224 digests. That is decrypted internally using keys that are derived from sceSblSsMgrDecryptWithPortabilityForDriver.

This function is also used in SceMagicGate.