rockbox-hiby-r1

Patch-maintenance repo for HiBy R1 Rockbox builds.

This repository does not vendor the full Rockbox source tree. Instead, it builds a HiBy R1 Rockbox release by:

1. fetching upstream Rockbox at a pinned commit
2. copying in extra source files from overlay/
3. applying the patch series from patches/
4. building release artifacts for the HiBy R1

What it adds

This patch set enables Bluetooth audio support for Rockbox on the HiBy R1, including:

• a Bluetooth menu in Rockbox
• device scan, pair, connect, disconnect, and status
• a Codec menu (Auto / SBC / AAC / aptX / aptX-HD / LDAC), persisted
• playback routing to BlueALSA A2DP, with working A2DP audio
• fallback to local audio output on disconnect/failure
• absolute volume updates from Rockbox to the Bluetooth stack
• Bluetooth preserved across the bootloader → Rockbox handoff

It also includes a small USB/ADB patch so ADB is handled through the existing USB mode path.

Bluetooth codec notes

On connect, Rockbox starts BlueALSA offering only SBC + AAC. This is deliberate: on the R1, BlueALSA's LDAC encoder negotiates a 96 kHz A2DP transport that the device cannot open for playback, which presents as "connected, but no audio." Restricting the offered codecs means the sink negotiates AAC (48 kHz), which plays cleanly. LDAC remains visible in the Codec menu but is not offered by the daemon on this hardware.

The audio data path uses a dedicated poll thread on a fixed interval, because BlueALSA does not implement ALSA async (SIGIO) handlers. (A poll-descriptor-driven variant was tried but regressed playback on this hardware, so the simple fixed-interval pump is used.)

Known issues

• Plugging in USB stops Bluetooth playback. USB insertion triggers the HiBy USB-gadget mode switch (per the usb mode setting, e.g. adb), which reconfigures the gadget and interrupts audio. Charging while playing is not currently supported; unplug and resume playback.

Repository layout

• patches/ — patch series applied on top of upstream Rockbox
• overlay/ — new files not present upstream
• scripts/build.sh — local reproducible build
• .github/workflows/ — CI and release automation
• baseline/ — provenance for the captured on-device baseline

Build outputs

A successful build produces:

• rockbox.r1 — Rockbox firmware
• bootloader.r1 — bootloader
• r1_rb.upt — flashable update package, when a base r1.upt is provided
• rockbox-info.txt — Rockbox build info
• build-metadata.txt — build provenance
• SHA256SUMS — checksums

Build locally

./scripts/build.sh

Artifacts are written to out/.

To also build a flashable .upt package:

R1_UPDATE_PATH=/path/to/r1.upt ./scripts/build.sh

Or:

R1_UPDATE_URL='https://example.invalid/r1.upt' \
R1_UPDATE_SHA256='<sha256>' \
./scripts/build.sh

Install

Update an existing Rockbox install

If Rockbox is already installed, replace:

/usr/data/mnt/sd_0/.rockbox/rockbox.r1

with the built rockbox.r1, then reboot into Rockbox.

Install a packaged release

If a release includes r1_rb.upt, use that through the normal HiBy R1 local update flow.

For most users, r1_rb.upt is the simplest way to install a full packaged build.

Releases

GitHub Actions builds release artifacts automatically for version tags:

git tag v0.1.0
git push origin v0.1.0

Known Issues

• Plugging in USB stops Bluetooth playback (USB-gadget mode switch); see Bluetooth codec notes → Known issues above.
• LDAC is not usable on this hardware (BlueALSA's LDAC encoder yields a 96 kHz transport that won't open); AAC is used instead.
• Bluetooth audio (A2DP, AAC) works; report any pairing/connect edge cases.