Booting to a framebuffer on real hardware

QEMU had been lying to me for months. Everything that worked in the emulator was supposed to work on metal, and for the most part it did — until the display. On a real ThinkPad, the screen stayed black for a full week while every other subsystem reported healthy.

The culprit was the UEFI Graphics Output Protocol. In QEMU the default framebuffer is linear, 32-bit, and sits exactly where you expect. On the ThinkPad the pixel format was BGR, the scanline stride was wider than the visible width, and the base address moved every boot.

The fix was to stop assuming anything. Ridge now queries GOP for the current mode, reads the exact PixelsPerScanLine, and maps only the framebuffer region reported by the firmware. Once the compositor drew to the real stride instead of the visible width, the desktop appeared — slightly sheared for one frame, then perfect.

The lesson, again: the emulator is a convenience, not the specification. Read the spec, query the hardware, assume nothing.