RSA Registers

Registers

NAME	PHYSICAL ADDRESS	WIDTH
REG_RSACNT	0x1000B000	0x04
REG_RSASLOT0	0x1000B100	0x10
REG_RSASLOT1	0x1000B110	0x10
REG_RSASLOT2	0x1000B120	0x10
REG_RSASLOT3	0x1000B130	0x10
REG_RSAKEY	0x1000B400	0x100
REG_RSAMSG	0x1000B800	0x100

REG_RSACNT

Bit	Description
0	Busy
1	Keyslot select related?
4-7	Keyslot
8-9	Should be set to 0x3 before accessing REG_RSAMSG

REG_RSASLOT

Start	Width	Description
0x0	0x4	REG_RSASLOTCNT
0x4	0x4	?
0x8	0x4	?
0xC	0x4	?

REG_RSAKEY

The RSA public key for the selected keyslot can be written here. When writing the RSA key, the key is copied to 0x1000B500-RSA_bytesize, length RSA_bytesize. The engine determines the RSA byte-size by checking where the first word of the key was written. The engine only supports RSA-2048 and below.

REG_RSAMSG

The RSA signature can be written here, and the data read from here is the message. The message padding must be checked by software. When writing the RSA signature, the signature is copied to 0x1000B900-RSA_bytesize, length RSA_bytesize. The engine determines the RSA byte-size by checking where the first word of the signature was written.

Keyslots usage

Keyslot	Description
0	Arbitrary
1	CXI access desc (following the exheader)
2-3	Unused