I have hp stream 11-y106ur with Insyde H2O bios. I have downloaded the latest bios, decrypted it and found the spd data inside. I want to solder new ram chips. I have 4GBof ram and want to upgrade to 8GB. I already upgraded emmc to 128GB (from 32) and next is CPU (4 core). But RAM is the problem, because it needs SPD data modification in bios. People say that signature is checked at every boot. Maybe it is possible to sign with my own signature? Replace signature? I don’t see any hacked bios for this laptop w/o rsa checks. Well, any information and thoughts will be appreciated.
btw One strange thing i found in the bios is several bad spd blocks.
I scanned for SPD block using CRC check (SPD has CRC16 XMODEM check) and i found only 3, but when i then searched for starting bytes i have found 2 more SPD blocks with the same data but incorrect CRC16 checksums. Crazy stuff.
I can modify the spd but then i cannot flash the bios because i cannot sign it.
I could probably use a hardware flasher to write bios data into the spi flash chip, but it has signature check and it will fail. So, i need to disassemble some module inside bios and kill the check. But what module is that?
I could not find the signature inside the bios itself. If i could find i would probably find the address access in the assembly.