so, it goes like this:
during a ps3 update, bluray drive firmware is temporarily decrypted and reencrypted into the flash.
so, you can e.g. use a logic analyzer on drives you know the testpoints to (like the SPI drives of new consoles or the NOR drives of old consoles), update the console and wait for the part where the firmware is decrypted. Then fetch the firmware from the logic dumps.
IF it’s an SPI drive, since the firmware is CTR encrypted, you can use the obtained firmware, xor it with the encrypted one to obtain xorstream, and apply xor stream to the rest of the SPI encrypted firmwares, and bingo! you have all the decrypted SPI bluray drive firmwares