Adds fb_draw_orientation_test() (framebuffer.c/.h): fills the four raster corners RED/GREEN/BLUE/YELLOW via fb_fill_rect. Wired into kernel_main.c calling fb_init() directly -- console_fb_init()/vt100_init() removed from the boot path, since vt100.c/console.c are superseded by the Console drawing-fabric redesign (FABRIC.md ss27) and should not be exercised even incidentally. The diagnostic caught a real, pre-existing bug on its first run: framebuffer.c's pack_pixel() had its FB_PIXEL_RGBX32/FB_PIXEL_BGRX32 branches swapped relative to UEFI GOP's own byte-order naming convention, producing a clean R<->B channel swap (G unaffected). Spatial placement was already correct -- no flip/rotation. Fixed by swapping pack_pixel's two return bodies to match framebuffer.h's already-correct doc comments; kernel_main.c's GOP-format switch needed no change. Also item 4.3.2 -- QEMU screenshot capability. scripts/qemu_screenshot.sh already existed (monitor socket + socat + HMP screendump), just unwired and unused this session. Redirected its PNG output to a new top-level fb/ directory (tracked in git, not logs/, not a gitignored temp dir) and added a python3+PIL fallback for PPM->PNG conversion since imagemagick isn't installed here. Left as a standalone script for now, not wired into a Makefile target. FABRIC.md items 4.3.1 and 4.3.2 marked done with acceptance evidence.
src/starkernel/
LithosAnanke — the bare-metal UEFI kernel that boots StarForth directly on
hardware (amd64/aarch64/riscv64). Built only via Makefile.starkernel; the
only valid acceptance test is the three-arch QEMU boot (see
.claude/CLAUDE.md), never make test.
kernel_main.c— kernel entry point, driving the boot milestones (console init, PMM, VMM, interrupts, timers, kmalloc heap, VM bootstrap).repl.c— kernel REPL.doe_log.c— kernel-side DoE (Design of Experiments) metrics logging.
Subdirectories:
arch/{amd64,aarch64,riscv64}/— per-architecture support (APIC/GIC/ PLIC interrupt controller, timers, boot/ISR assembly).boot/— UEFI loader, ELF loading, kernel command-line parsing.capsule/— capsule birth/run/load/validate pipeline.hal/— hardware-abstraction-layer implementation (console, framebuffer, VT100, memory, host services).hash/— XXHash64 content-addressing implementation.math/— kernel-build Q48.16 fixed-point arithmetic.memory/— physical/virtual memory managers and the kernel heap.pci/— PCI bus enumeration.virtio/— VirtIO block device driver.vm/— kernel VM subsystem (bootstrap, core interpreter, parity logging, capsule arena).
See include/starkernel/README.md for the corresponding headers.