a1c965da1e
Sixty-five headers sat side by side in include/, so `#include "irq.h"` said nothing about where irq.h was or what it belonged to, and errno.h, stat.h and fcntl.h at the top shadowed the system's for any host tool built with -I./include. They are in folders now -- arch/ core/ fs/ dev/ gfx/ net/ uapi/ (and ldls/ for the Linux driver layer) -- and every include names the folder, as Linux's do: "core/proc.h". Done mechanically and checked the hard way: the kernel built from this tree disassembles identically to the one built from the tree before it. The full image boots, and userland is the same set of programs. Paths in docs and comments follow; docs/guides/layout.md has a table of what is where, and tools/fix-includes.py rewrites old-style includes from the folders in the tree, for code written before this. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01S1giNvrHTrPMPw7V6x1kQ4
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| name | description | metadata | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| schunix-boot-splash-logo | The boot logo pipeline, why the loader draws it rather than the kernel, and the STAGE2_SECTORS trap that consolidating it exposed. |
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The boot splash shows the Assets/Schunix Small Logo.png mark (an SX monogram in
a ring) above the S C H U N I X wordmark and its accent rule, all centred as
one group. Verified rendering correctly on 2026-08-08.
The logo is drawn by the bootloader, not the kernel. This is the
counter-intuitive part and it is a timing fact, not a preference: the kernel does
not reach vga_init() until roughly the last 300ms of a ~2.8s boot, so a
kernel-drawn logo appeared for about one frame before console_takeover() wiped
it. Drawn from splash() in boot/stage2main.c it is up for the whole boot.
kernel/dev/vga.c keeps the same drawing code against the same mask
(vga_draw_logo, vga_logo_centered) for things that want the mark after
boot — the crash screen, eventually schinit. Don't "fix" the duplication by
deleting the loader's copy.
Pipeline: tools/mklogo.py (host Python, has its own PNG inflate +
un-filter) crops to the mark, box-downscales, normalises to full strength, packs
to a 4-bit coverage mask, and writes include/gfx/logo.h. Run make logo — it is
not a build dependency, and include/gfx/logo.h is committed, on the same
reasoning as include/gfx/font.h. The mask is coverage, not colour, so the palette
stays in schunix-console-tty's include/gfx/theme.h; the loader composites it in
SCH_FG because the source art is a silver gradient and the accent is reserved
for the one rule. 4 bits rather than 8 because the header is included by the
bootloader, where size is a boot constraint.
STAGE2_SECTORS was encoded in five places, not the three docs/guides/layout.md
claimed. Raising it 24 → 48 to fit the 8 KiB mask proved it: the dd seek=25
offset stayed behind and the kernel got written straight over stage2's tail.
The five were boot/bootasm.S, boot/stage2main.c, the dd seek=, and twice
inside tools/mkiso.sh (its size assertion and -boot-load-size). It now lives
only in the root Makefile, which passes -DSTAGE2_SECTORS and exports it to
mkiso; the #defines left in the boot sources are #ifndef fallbacks. Hard
ceiling is 65 sectors — stage2 loads at 0x7E00 and must not reach the
multiboot kernel-search buffer at 0x10000 — and stage2main.c now
static-asserts that. See also schunix-iso-boot.
tools/splashshot.ps1 captures a burst of QEMU screendumps across early
boot and reports each frame's distinct-colour count, because the splash window
is too short to hit with a single guessed delay. It uses -snapshot plus
file.locking=off so it runs while an interactive QEMU has the images open —
booting from copies also works but means duplicating all 153 MB of
build/fs.img per run. Colour counts are the
assertion: ~2 means text console or blank, 18 means the 4bpp logo is up. If it
ever reads 156 again, something is drawing an 8-bit mask.
Two traps, both hit while doing this:
$(shell expr $(N) \* 512)in a Makefile does not work — make passes the backslash through, sh globs the*, and expr receives a directory listing. Make silently carries on with nonsense. Use$$(( ))in the recipe.make isowas failing when this was written, for unrelated reasons since fixed — see schunix-ramdisk-root-sizing.-boot-load-size 49is now verified: the ISO boots from optical media only.