sl0pboy.git, branch master

docs: document the SL0PBOY boot-logo patcher (tools/mk_sl0pboy_bios.py)

2026-07-18T20:47:08Z

Add a BIOS subsection covering usage (Pillow dep, SL0P_TEXT/SL0P_FONT knobs, the preview PNG), how the in-place $0607 blob patch works, and why the forked binary stays out of git while the generator ships.

tools: mk_sl0pboy_bios.py - fork the CGB boot ROM's GAME BOY -> SL0PBOY

2026-07-18T20:45:06Z

The stock CGB boot ROM draws its GAME BOY wordmark from a 192-byte blob at $0607 (routine $03F0 copies it to VRAM tiles $08-$37: 48 tiles, 4 bytes each, every byte a row doubled vertically). This re-encodes that blob with a bold-italic SL0PBOY bitmap of the same size and patches it in place over a local bios/gbc_bios.bin -> bios/sl0pboy_bios.bin. No code moves; the cart's own Nintendo logo ($104) is untouched so the integrity check still passes and the boot hands off normally. bios/ stays gitignored (copyrighted boot ROM); run this to produce the fork locally. Verified end to end: logo drop + color + chime -> gbos.

hooks: clang-format pre-commit (changed lines only) + .clang-format

2026-07-18T18:57:37Z

git-clang-format scopes formatting to the lines each commit touches - a full-file reformat would destroy the deliberately dense hand formatting (opcode tables, multi-statement helpers). The hook re-adds formatted files (git-clang-format --staged fixes the worktree, not the index) and refuses partially-staged C files rather than mixing staged and unstaged changes. Enable once: git config core.hooksPath hooks

README: fix source paths in Architecture table (src/ prefix)

2026-07-18T18:53:17Z

The Architecture table listed the core sources as bare filenames (types.h, cart.c, ...), but they live under src/. Prefix them with src/ so the paths actually point at the files.

render: --shrink N - downscale the half-block live display (1-4)

2026-07-18T18:41:19Z

Decimates the LCD N x N before the half-block encode so the monitor pane takes 160/N cols x 72/N rows. Display-only: capture, recording and sixel still read the full-res framebuffer. Decimation is max-luma pick, not box-average: terminal fonts are 1px bright strokes on dark background, and averaging dims them into grey mush (the 'blurry font' regression). Keeping the brightest source pixel of each block preserves stroke brightness and hue.

main: allow --sock (control/debug socket) in headless mode

2026-07-17T18:22:13Z

The control socket was only opened on the windowed path, so a --headless GB couldn't be inspected. A scriptable, invisible GB is exactly the one you most want to peek into - reading kernel WRAM over the debug socket is how the TCP field-offset corruption got pinned down. Open it in the headless loop too and poll it each frame; close it on exit.

cpu: log the $ED poweroff opcode with pc/registers

2026-07-17T17:47:02Z

The clean-exit opcode used to print nothing, so any guest crash that walked into a stray $ED byte was indistinguishable from a silent socket death (one of the kill vectors in the link-drop investigation). Now it identifies itself on stderr with pc/af/bc/de/hl/sp.

gb: auto-reconnect a dead --serial-sock link instead of going silent

2026-07-17T17:46:58Z

Root-cause work for the 'idle link-socket drop' (see gbos docs/link-drop-investigation.md): when the hub restarts or the bridge dies, the link fd went dead forever - and before SIGPIPE was ignored, the next console-echo write() would kill the whole emulator silently. Now, in --serial-sock mode, EOF on read or EPIPE/ECONNRESET/ENOTCONN/ EBADF on either direction marks the link dead, closes the fd, and retries connect() every 500ms from the serial poll path (the guest polls constantly, so no extra plumbing). RX stays pending while down (serial_no_eof semantics), so the guest just sees a quiet link that comes back. Logs 'link socket lost / reconnected' either way. Verified: SIGKILL the hub, restart it - every GB reconnects within ~1s and keeps its lease.

main: silence stderr while the live sixel display is up

2026-07-17T17:45:03Z

Runtime chatter (link reconnect notices, input debug, cart warnings) was landing mid-sixel-stream and corrupting the picture. Redirect fd 2 to /dev/null for the duration of the display loop; restored on exit so the final stats line still prints. Startup errors before the display begins are unaffected.

main: --serial-sock PATH - link port over a unix socket (net + live display)

2026-07-17T11:22:00Z

The serial fds are serviced by cpu_step in every mode, so wiring them to a connected unix socket lets networking run alongside a live display (--sixel / terminal) - unlike --headless, which needs stdio for the serial. The emulator connects to PATH (retrying ~1s so a launcher can listen first) and uses it non-blocking with no EOF-exit; it overrides the headless stdio serial. Pairs with gbos tools/netboot, which listens on PATH, brings up a TUN+NAT, and bridges the socket <-> TUN. In windowed mode the OSK is the console and the link port is pure network - cleanly separated. Verified: host pings the GB 3/3 over the socket link.