# CB-C6s-STU GSI Fixes

TWRP flashable zip that applies device-specific fixes for the **CB-C6s-STU**
tablet when running a Generic System Image (GSI). All `build.prop` changes
are **appended** — the existing file is never replaced.

## What it fixes

| Area | File | Problem | Fix |
|------|------|---------|-----|
| System properties | `build.prop` | Missing tablet characteristics, wrong brightness range, portrait-only orientation, broken Bluetooth A2DP offload | Append missing properties |
| Touchscreen | `goodix_ts.idc` | Touch orientation and input device type not declared | Install IDC config for Goodix touch panel |
| Camera sensors | `sensor_config.xml` | Rear/front camera sensor modules not configured | Install sensor config for hi846 / gc8034 modules |

## Files

```
CB-C6s-STU-GSI-Fixes.zip
├── META-INF/com/google/android/
│   ├── update-binary        # Shell script — all install logic
│   └── updater-script       # Placeholder (TWRP uses shell-script mode)
├── system/
│   ├── build.prop           # Properties appended to /system/build.prop
│   └── usr/idc/
│       └── goodix_ts.idc    # Touchscreen input device config
└── vendor/etc/
    └── sensor_config.xml    # Camera sensor module mapping
```

### build.prop entries

Appended to the device's existing `/system/build.prop`:

```ini
# Tablet characteristics
ro.build.characteristics=tablet

# Workaround: Set max brightness of sprd_backlight to 1023
persist.sys.qcom-brightness=1023

# Workaround: Set primary display orientation to landscape
ro.surface_flinger.primary_display_orientation=ORIENTATION_90

# Workaround: Disable Bluetooth A2DP offload
ro.bluetooth.a2dp_offload.supported=false
persist.bluetooth.a2dp_offload.disabled=true
```

A backup is saved to `/system/build.prop.bak` before appending.

## Usage

1. Copy `CB-C6s-STU-GSI-Fixes.zip` to the device (sdcard or adb push).
2. Boot to **TWRP Recovery**.
3. Tap **Install** → select the zip → **Swipe to confirm Flash**.
4. Reboot.

The script mounts `/system` and `/vendor` automatically. No manual
mounting is needed.

## TWRP install output

During flash, TWRP will show:

```
[1/3] Appending entries to /system/build.prop...
[2/3] Installing goodix_ts.idc...
[3/3] Installing sensor_config.xml...
```

## Compatibility

- **Device**: CB-C6s-STU tablet (Spreadtrum / Unisoc platform)
- **Recovery**: TWRP with `/sbin/sh` support (shell-script update-binary)
- **GSI**: Any Android GSI that needs these device-specific tweaks

## Notes

- The `build.prop` entries are **appended with dedup** — each property key
  (`key=value`) is only added if the key does not already exist in
  `/system/build.prop`. Re-flashing the zip multiple times is safe and
  will **not** duplicate entries.
- The `sensor_config.xml` covers four camera sensor combinations:
  rear (`hi846`, `gc8034_rear`) and front (`hi846_front`, `gc8034`),
  each with OTP EEPROM tuning parameters.
- For SAR (System-as-Root) devices, the script falls back to
  `/system/vendor/etc/` if `/vendor/etc/` is not available.

## License

Provided as-is for device maintenance. No warranty.