A walkthrough on patching Dell UEFI firmware at the SPI flash level to disable pre-boot DMA protection — bypassing the BIOS password entirely. The interesting part: the UEFI UI still reports the setting as enabled, and TPM measured boot doesn't detect the NVRAM change, so BitLocker unlocks normally. The patch also persists through official Dell BIOS updates. From there it's DMAReaper to kill IOMMU + PCILeech for a SYSTEM shell. Significant measured boot policy gap. https://www.mdsec.co.uk/2026/03/disabling-security-features-in-a-locked-bios/