v1.1.1 - macOS build fix + audiobook chapters

diskOS v1.1.1

Image builds now work on the default macOS filesystem. This fixes the E230
unsquashfs ... already exists failure caused by stock firmware files whose names differ only
in case.

v1.1.1 builds on v1.1.0, which introduced
V2.40 support and the UI refresh: album cover flow, audiobooks with chapters and saved progress, folder browsing,
multilingual library text, and safer USER EQ preset selection.

What's fixed

On a case-insensitive macOS filesystem, the installer now automatically creates a case-sensitive
APFS scratch image using hdiutil, mounts it, and verifies its case sensitivity before extracting
the root filesystem. The rebuilt image's validation extraction uses the same volume.

The installer handles detaching the volume and removing the scratch image afterward, with warnings
if cleanup cannot finish. No manual case-sensitive volume setup or workspace relocation is needed
for normal macOS builds.

The scratch-volume mechanism is a no-op on Linux with a case-sensitive filesystem and on
case-sensitive macOS volumes.

Tested

• Linux x86-64: builds and flashes end to end on hardware with V2.09, V2.28, and V2.40.
• macOS: image builds now succeed on the default case-insensitive filesystem. Real-Mac
  validation confirmed that back_home.png and BACK_HOME.png coexist after extraction.
  Device flashing from macOS remains unverified end to end: no flash with a device attached
  to a Mac has been completed.

Local playback is the well-tested listening path. Weather and Last.fm remain experimental;
Last.fm has not completed live end-to-end verification. USB DAC, Bluetooth receiver, and USB
storage have less coverage than local playback.

Install, update, or return to stock

Use the complete v1.1.1 installer with its matching flash tools and your own official FiiO firmware
.zip. Both the graphical and command-line installer build the image locally. No FiiO root
filesystem is included in the release.

Updating the on-device UI requires another flash; there is no on-device update path. The macOS
change in this release fixes the host-side image build process.

Back up your data and keep the installer's saved stock image on separate storage.
Run ./diskos-installer restore-stock to reflash that validated stock root filesystem, including
older short backups. The saved image is reconstructed from your firmware archive, not a dump of
your original device partition. Restore deactivates diskOS but leaves inactive files under
/usr/data; it is not a factory wipe.

You can also select Settings > System > Default UI > Stock, or hold Volume Up at power-on
for a one-time stock boot. Optional SSH Debug Mode remains off by default.

Read the README for installation,
requirements, recovery, and known issues. Do not redistribute generated diskos_*.bin images:
they contain FiiO's root filesystem.

The installer, build scripts, and documentation remain MIT licensed. The on-device UI source
is GPL-3.0-or-later. Bundled third-party components retain their own licenses.

Acknowledgements

Thanks to the contributors for their reports, tools, and fixes:

• eudj1n reported the V2.40 image-size issue
  (#1) with a byte-exact stock rootfs reproduction,
  reported the Cyrillic rendering issue (#3),
  and built a QEMU preview harness.
• Pierre Nel (@pierrenel) contributed the macOS
  case-insensitive-filesystem fix (PR #2).
• zmd22 corrected the V2.40 0657 work-mode command table from
  hardware testing (discussion #6) and shared
  UI customizations (discussion #5).

Full changelog

Caution

diskOS remains an unsupported hobbyist beta. Installation rewrites the main root filesystem;
power loss, host sleep, a bad cable, a defect, an unsupported device, or an interrupted flash
can leave the player unbootable, lose data, require hardware recovery, or void its warranty.
Recovery worked on tested units but is not guaranteed. Back up your data before installing.
Not affiliated with or endorsed by FiiO, Snowsky, or Ingenic. No warranty or support is promised.