https://tsvinc.dev/tags/uefi/ Recent content in Uefi on tsvinc Hugo en-us Sat, 10 Oct 2026 00:00:00 +0000 https://tsvinc.dev/posts/no-bios-image-diff-nvram/ Sat, 10 Oct 2026 00:00:00 +0000 https://tsvinc.dev/posts/no-bios-image-diff-nvram/ <p>flashrom got two attempts at the GEEKOM A9 Mega's SPI flash. Both were read-only: <code>-r</code>, run twice, so the two dumps could be hashed against each other before anyone trusted them. The package was Fedora 45's <code>flashrom-1.6.0-6.fc45</code>.</p> <p><strong>Attempt one, Secure Boot on.</strong> The kernel is in lockdown, and lockdown takes raw port I/O away from userspace: <code>ioperm</code> and <code>iopl</code> are on its refusal list. flashrom never reaches the chip.</p> <p><strong>Attempt two, Secure Boot off.</strong> flashrom runs, and names the chipset &quot;AMD FP4&quot;. The CPU is a Ryzen AI Max+ 395, family 0x1A, model 0x70: Strix Halo. Whatever flashrom thinks it is talking to, it is not this. It fails to lift the ROM protection, changes nothing, and segfaults.</p>