The bootrom is located at 0xBFC20000 and is 0x2000 bytes large. The bootrom is largely made up of NAND reading, aes decryption and sha1 hashing code. Its primary function is to load the Secure Kernel from NAND, decrypt it, hash it and compare the hash, before jumping to it. It compares the hash against the hash stored in Virage2. The key and IV used to decrypt SK are located within the bootrom, the key being at offset 0x1460 and the IV being at 0x1470.