nx_gop_present.nx

nx_gop_present.nx -- LIB: the UEFI GOP linear-framebuffer PRESENTATION SINK (the x86 on-metal display path). SF1/SF2/SF4 put pixels on the sovereign SILICON (fabric + behavioral RV64IM). This is the OTHER half of "both": delivering the games' framebuffer to a REAL x86 screen via the UEFI Graphics Output Protocol's linear framebuffer -- the destination the nx_swapchain roadmap queued as NX_SWAP_DEST_KMS_DIRECT / NX_SWAP_DEST_NISHI_OS (honestly stubbed NOT_IMPL there). This is that backend, implemented. A GOP linear framebuffer (EFI_GRAPHICS_OUTPUT_PROTOCOL->Mode->FrameBufferBase) is 32 bits/pixel with: - a STRIDE in PIXELS (PixelsPerScanLine) that may EXCEED the visible width -> rows are padded; writing `width` pixels per row instead of advancing by `pitch` shears the image (the swapchain hazard "stride-vs-width-confusion"). - a PIXEL FORMAT: PixelRedGreenBlueReserved8BitPerColor (RGBX) or, the common one on real HW / OVMF / QEMU, PixelBlueGreenRedReserved8BitPerColor (BGRX) -- writing the wrong channel order swaps red/blue (the hazard "rgba-vs-rgb-channel-order"). BitMask / BltOnly are honestly refused (NOT_IMPL), never a silent no-op (the hazard "silent-stub-no-op"). NEVER-BRICK (#26): a pixel BLIT to a GOP linear framebuffer is volatile VRAM = a `gui`-axis capability that cannot corrupt firmware/CMOS/NVRAM BY CONSTRUCTION. (The GOP MODE-SET -- SetMode, which picks the resolution -- is the firmware-adjacent part; that is a SEPARATE rung registered firmware-axis with an idempotent / read-back-verify / never-flash guarantee. This sink only BLITS into an already-configured framebuffer.) Bounded (exactly w*h pixel writes), total, deterministic. license_tier: ORIGINAL