4 ms·
A more useful hack is unlocking AES-NI with the same method. Some laptops have AES instructions permanently disabled on boot via BIOS by the OEM to comply with
by segfaultbuserr 4y ago
A more useful hack is unlocking AES-NI with the same method. Some laptops have AES instructions permanently disabled on boot via BIOS by the OEM to comply with regional cryptography regulations, such as some Lenovo Thinkpad models in Russia. In the 2010s, disassembling the BIOS and patching a single line away can regain hardware AES functionality. Unfortunately it's no longer possible after Boot Guard's BIOS lockdown.
- Avamander 4y agoReference for that last sentence?
- segfaultbuserr 4y agoWith Intel Boot Guard (now almost pre-enabled on all laptops on the market), the CPU verifies the digital signature of BIOS code. The public key is burned into the chip [0] by the OEM before it leaves the factory. If signature verification fails, the CPU refuses to execute any code. Naturally, any code modification in the BIOS causes the check to fail and effectively bricking the BIOS. [0] Actually the PCH, aka southbridge, not the CPU. But it's not much of a difference for end users. See: * Intel Boot Guard, Coreboot and user freedom https://mjg59.dreamwidth.org/33981.html https://mjg59.dreamwidth.org/33981.html * Why You Don't See Coreboot Supported By Many Modern Intel Systems https://www.phoronix.com/news/Intel-Boot-Guard-Kills-Coreboot https://www.phoronix.com/news/Intel-Boot-Guard-Kills-Coreboo... * Bootguard (for a technical description) https://trmm.net/Bootguard/ https://trmm.net/Bootguard/