Files
LithosAnanake/include/starkernel
Robert Allan JamesandClaude Opus 5 f81e9c92bc Fix framebuffer console: scroll drift causes progressive line overlap in TTF mode
fb_scroll_rows() hardcoded the pixel distance it physically shifts the
framebuffer by as char_rows * 16 * scale -- the bitmap-font (font_8x16.c)
cell height -- regardless of which glyph mode vt100.c actually had active.
In TTF mode (the REPL's default, cell height 24px via VT100_TTF_CELL_H_PX)
this meant every scroll_up(1) call physically shifted the framebuffer by
only 16px while the text model (g_vt.rows, py_of()) placed each row 24px
apart. That 8px-per-scroll shortfall compounds with every subsequent
scroll: a few scrolls barely show it, but enough scrolls -- or scrolling
quickly, which is just many scrolls in a short span -- accumulates into
visible pixel overlap between rows, with newer lines drawn on top of the
tail end of older ones.

fb_scroll_rect() (the box-confined scroll added later for 4.4t) already
carried a doc comment calling this out explicitly, describing its own
explicit pixel_rows parameter as the fix for fb_scroll_rows()'s "fixed
16px-row assumption" -- fb_scroll_rows() itself was just never updated to
match.

Fixed by changing fb_scroll_rows()'s parameter from an implicit char_rows
count to an explicit pixel_rows count (matching fb_scroll_rect()'s
existing convention), and having its one caller (vt100.c's scroll_up())
pass lines * cell_h() -- the real active cell height -- instead of a raw
line count for the callee to guess at.

Verified: booted amd64 to the REPL (TTF mode active per sk_repl()'s own
console_fb_enable_ttf() call), let boot chatter + WORDS output scroll the
screen through thousands of accumulated scroll_up() calls, then measured
every visible line's y-position via a QMP screendump. Spacing held at a
perfectly consistent 24px (TTF cell height) top to bottom with zero drift
-- the old hardcoded-16px bug could not have produced that after this many
scrolls. Re-verified boot to ok> on all three architectures
(amd64/aarch64/riscv64) per repo acceptance policy.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-02 17:25:06 -04:00
..
2026-08-01 07:49:56 -04:00
2026-09-01 12:07:32 -04:00
2026-08-01 07:49:56 -04:00
2026-09-01 12:07:32 -04:00
2026-08-01 07:49:56 -04:00

include/starkernel/

Headers for LithosAnanke, the bare-metal UEFI kernel (src/starkernel/). Built only via Makefile.starkernel; gated by __STARKERNEL__ when shared with hosted code.

  • uefi.h — UEFI protocol/type definitions consumed by the loader.
  • elf64.h, elf_loader.h — ELF64 parsing and kernel-image loading.
  • boot_info_offsets.h — struct-offset constants shared between the assembly bootstrap and the C boot path.
  • arch.h, apic.h, timer.h — architecture init, APIC interrupt controller, timer (TSC/HPET/APIC, 100 Hz heartbeat).
  • console.h, framebuffer.h, vt100.h — UART 16550 console, framebuffer driver, and VT100 terminal emulation over the framebuffer.
  • pmm.h, vmm.h, kmalloc.h — physical memory manager (bitmap allocator), 4-level x86_64 paging, kernel heap allocator.
  • pci.h, virtio_blk.h — PCI enumeration and the VirtIO block device driver (disk backend for the kernel block subsystem).
  • capsule.h, capsule_birth.h, capsule_loader.h, capsule_run.h, capsule_vm_physics.h, capsule_generated.h — capsule system types, birth protocol, physics-runtime capsule bindings, and the build-time- generated capsule directory (see tools/mkcapsule.c).
  • kernel_args.h, cmdline.h — boot-time kernel argument parsing (starforth.cfg / command line).
  • repl.h — kernel REPL.
  • log.h, doe_log.h — kernel logging and DoE metrics logging.
  • q48_16.h — kernel-build copy of Q48.16 fixed-point arithmetic.
  • xxhash64.h — content-addressing hash used for capsule IDs.
  • hal_memory.h — hardware-abstraction-layer memory interface.

Subdirectories:

  • hal/ — top-level hardware-abstraction-layer interface.
  • vm/ — kernel VM subsystem headers (capsule arena, parity logging, bootstrap wiring).
  • freestanding/ — minimal libc-shim headers (assert.h, ctype.h, errno.h, inttypes.h, math.h, sched.h, signal.h, stdio.h, stdlib.h, string.h, time.h, sys/time.h, sys/types.h) for building shared VM code in the freestanding kernel environment, where no real libc is available.