Image tooling and prep for the v6 disk image release#382
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WIN95_PROBE_RESTORE=1 makes the probe harness restore the saved/default state instead of cold-booting, so a freshly generated default-state.bin can be verified headlessly. Also document when to retry probe failures versus treat them as real.
tools/slim-disk.sh deletes dead content (online-service installers, MSN setup cabinets, uninstall backups, NetMeeting, caches) from the disk image via mtools; tools/zero-free-clusters.py zeroes free clusters without touching the FAT so the packed zip compresses better. Both are currently shelved: offline modification of the image worsens v86 cold-boot reliability. The failure modes, reliability data, and a repro kit are in docs/v86-cold-boot-bug.md, and docs/qemu.md now describes the recommended in-Windows cleanup workflow instead. Also git-ignore packed images_*.zip release artifacts.
The v6 images release ships a cleaned-up disk and a freshly generated default-state.bin. Old state-v5 snapshots reference the previous disk layout and must go through the legacy recovery flow instead of resuming over the changed disk.
- emulator: initialize isBootingFresh to false (bootFromScratch sets it itself); in restore-probe mode, refuse to boot when there is no state file so a missing default-state.bin cannot pass as a false SUCCESS; split getStateFilePath() out of getState() so the existence check does not read the whole state file - zero-free-clusters: read the partition offset from the MBR instead of hardcoding it, and coalesce free-cluster runs into large reads/batched writes (minutes -> under a second on a ~700 MB free region) - slim-disk: collapse the vestigial tier arrays into DELETE_DIRS / DELETE_FILES / EMPTY_DIRS (the empty-and-recreate dirs were listed twice), document --no-zerofill, drop the duplicated post-run checklist - constants: correct the STATE_VERSION comment - legacy-state recovery extracts files to a host folder, it does not produce a mountable .img - docs/skills: state the probe retry/ship policy once (probe-win95 skill) and link to it from qemu.md and the bug doc; renumber the inspect-disk warnings and fix its stale slim-disk recommendation Verified: tsc, prettier, dry-run parity (41 targets), and live probes of both boot paths (cold boot + state restore) after the changes.
Fold the essential facts (known triggers, QEMU-boots-but-v86-doesn't symptom, retry policy) into the probe skill's "VXDLINK: flake vs. real bug" section, which the other docs already point at, and drop the standalone document.
The offline-deletion workflow is not recommended (it worsens v86 cold-boot reliability), so don't keep a tool whose own header says not to run it. The in-Windows cleanup checklist in docs/qemu.md covers what it deleted; tools/zero-free-clusters.py stays as the only safe way to zero free space if that is ever needed. Also drop a redundant comment on isBootingFresh.
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What this does
Prepares the app for the v6 disk-image release: a much smaller images zip (298 MB → 153 MB), a regenerated default state, and the tooling/docs that came out of building it.
The image and default-state binaries themselves are not in this PR — they ship via the private images release (
images_v6_slimmed.zip, built withtools/pack-disk.sh).What changed
STATE_VERSION 5 → 6 (
src/constants.ts). The v6 image has different content than v5, so old saved states must go through the legacy recovery flow instead of resuming over the new disk.Probe harness: state-restore mode (
src/renderer/emulator.tsx).WIN95_PROBE_RESTORE=1 tools/probe-boot.shboots the app and restores the saved/default state instead of cold-booting, so a freshly generateddefault-state.bincan be verified headlessly. Refuses to boot if there is no state file, so a missing state cannot pass as a false SUCCESS. This is now part of the release checklist.tools/zero-free-clusters.py: zeroes free clusters directly (FAT untouched) so the packed zip compresses better — the only safe way to do this; the classic "mcopy a giant zero file, then delete it" trick deterministically breaks Win95 cold boot in v86. Currently shelved along with all offline image modification (see below).Docs/skills.
docs/qemu.mdnow documents the recommended image-cleanup workflow: do it inside Windows (Explorer delete + ScanDisk + clean shutdown), verify with the probe, ship the image untouched. Offline modification (mtools) measurably worsens v86 cold-boot reliability — Win95 can hit "Invalid VxD dynamic link call" on cold boot in v86 while the same image boots fine in QEMU and passes fsck. The probe skill gains a "VXDLINK: flake vs. real bug" section with the canonical verdict-interpretation policy: cold boot fails sporadically (~1 in 2–3 attempts) on any image; one SUCCESS means the image is good, three identical failures mean the image content must change.How this was verified
tools/probe-boot.sh) of the v6 imageWIN95_PROBE_RESTORE=1) of the newdefault-state.bin— passes every runyarn run tscand prettier passAfter merge
images_v6_slimmed.zipto the private images release and pointDISK_TAGat it