Files
LithosAnanke/src/starkernel
Robert Allan James ab96ac0970 starkernel: item 4.3.1 -- framebuffer orientation test, found and fixed a real color-swap bug
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the boot path, since vt100.c/console.c are superseded by the Console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.
2026-08-07 11:38:33 -04:00
..

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.