Raspberry Pi 5 Secure Boot: What the EEPROM Bootloader Verifies, and What It Doesn’t
"Enrolling my own keys" on a Raspberry Pi 5 does not work like UEFI Secure Boot key enrollment. There is no key-management menu, no PK/KEK/db variable store, and no way to add a second trusted key later. The documented procedure is one-time-programmable (OTP) fuse provisioning plus a signed EEPROM configuration block and a signed boot image. The Raspberry Pi usbboot secure-boot documentation states the constraint plainly: "Once secure-boot has been enabled by programming the one-time programmable (OTP) fuses, it cannot be disabled and a different key cannot be programmed" (usbboot, docs/secure-boot.md). The quickstart repeats it: "Enabling signed boot modifies the OTP memory and is irreversible" (secure-boot-example/README.md). That single fact reframes the compliance question. The interesting audit question is not whether the device booted code the vendor authorized. It is whether…