Initial commit: CB-C6s-STU GSI Fixes

TWRP flashable zip for CB-C6s-STU tablet running GSI.
- build.prop: append tablet characteristics, brightness, orientation, BT offload
- goodix_ts.idc: touchscreen IDC config
- sensor_config.xml: camera sensor module mapping (hi846 / gc8034)
- Shell-script update-binary with append-only build.prop logic

.gitignore

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+# TWRP flashable zip output
+*.zip

META-INF/com/google/android/update-binary

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+#!/sbin/sh
+
+# ============================================================
+# TWRP Flashable Zip — CB-C6s-STU-GSI-Fixes
+#
+# This is a shell-script update-binary. TWRP extracts the zip,
+# sets the working dir to that temp location, and runs this script.
+# The updater-script is a dummy — all logic lives here.
+#
+# What it does:
+#   - Appends build.prop entries to /system/build.prop (not replace!)
+#   - Installs goodix_ts.idc to /system/usr/idc/
+#   - Installs sensor_config.xml to /vendor/etc/
+# ============================================================
+
+OUTFD=$2
+ZIPFILE=$3
+
+# ----- helpers -----
+ui_print() {
+  echo -n -e "ui_print $1\n" > /proc/self/fd/$OUTFD
+  echo -n -e "ui_print\n" > /proc/self/fd/$OUTFD
+}
+
+abort() {
+  ui_print " "
+  ui_print "ERROR: $1"
+  ui_print "Installation aborted."
+  exit 1
+}
+
+# ----- locate zip root -----
+# The script lives at:  META-INF/com/google/android/update-binary
+# Zip root is 3 levels up from the script's directory.
+SCRIPT_DIR=$(cd "$(dirname "$0")" && pwd)
+ZIPROOT=$(cd "$SCRIPT_DIR/../../.." && pwd)
+
+ui_print "========================================"
+ui_print "  CB-C6s-STU-GSI-Fixes"
+ui_print "  Tablet GSI tweaks"
+ui_print "========================================"
+
+# ----- mount partitions -----
+ui_print " "
+ui_print "Mounting partitions..."
+
+mount /system 2>/dev/null
+mount /vendor 2>/dev/null
+
+# Verify /system is accessible
+if [ ! -d /system ] || [ ! -f /system/build.prop ]; then
+  abort "Cannot access /system. Is the system partition mounted?"
+fi
+
+ui_print "Partitions ready."
+
+# ----- 1. APPEND build.prop (关键：追加，不覆盖) -----
+ui_print " "
+ui_print "[1/3] Appending entries to /system/build.prop..."
+
+BUILDPROP_SRC="$ZIPROOT/system/build.prop"
+
+if [ ! -f "$BUILDPROP_SRC" ]; then
+  abort "build.prop not found inside zip."
+fi
+
+# Backup original before modifying
+cp /system/build.prop /system/build.prop.bak 2>/dev/null
+chmod 644 /system/build.prop.bak 2>/dev/null
+
+# APPEND — 使用 >> 追加而非覆盖
+cat "$BUILDPROP_SRC" >> /system/build.prop
+chmod 644 /system/build.prop
+
+ui_print "build.prop: entries appended. Backup at build.prop.bak"
+
+# ----- 2. Install touchscreen IDC -----
+ui_print " "
+ui_print "[2/3] Installing goodix_ts.idc..."
+
+IDC_SRC="$ZIPROOT/system/usr/idc/goodix_ts.idc"
+IDC_DST="/system/usr/idc/goodix_ts.idc"
+
+if [ -f "$IDC_SRC" ]; then
+  mkdir -p /system/usr/idc 2>/dev/null
+  cp -f "$IDC_SRC" "$IDC_DST"
+  chmod 644 "$IDC_DST"
+  ui_print "goodix_ts.idc installed."
+else
+  ui_print "goodix_ts.idc not found — skipped."
+fi
+
+# ----- 3. Install sensor config -----
+ui_print " "
+ui_print "[3/3] Installing sensor_config.xml..."
+
+SENSOR_SRC="$ZIPROOT/vendor/etc/sensor_config.xml"
+
+if [ -f "$SENSOR_SRC" ]; then
+  # /vendor may be a separate partition OR a symlink under /system
+  if [ -d /vendor/etc ]; then
+    cp -f "$SENSOR_SRC" /vendor/etc/sensor_config.xml
+    chmod 644 /vendor/etc/sensor_config.xml
+    ui_print "sensor_config.xml → /vendor/etc/"
+  elif [ -d /system/vendor/etc ]; then
+    cp -f "$SENSOR_SRC" /system/vendor/etc/sensor_config.xml
+    chmod 644 /system/vendor/etc/sensor_config.xml
+    ui_print "sensor_config.xml → /system/vendor/etc/"
+  else
+    ui_print "WARNING: /vendor/etc not found — skipped."
+  fi
+else
+  ui_print "sensor_config.xml not found — skipped."
+fi
+
+# ----- done -----
+ui_print " "
+ui_print "========================================"
+ui_print "  Installation complete!"
+ui_print "  Reboot to apply changes."
+ui_print "========================================"
+
+exit 0

META-INF/com/google/android/updater-script

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+# CB-C6s-STU-GSI-Fixes
+# This updater-script is intentionally minimal.
+# The real installation logic is in update-binary (shell script).
+# TWRP runs the shell-script update-binary directly and ignores this file.

README.md

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+# 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, not replaced**. Re-flashing
+  the zip multiple times will duplicate the entries — restore from
+  `/system/build.prop.bak` if needed, or inspect the file first.
+- 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.

system/build.prop

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+# Tablet characteristics
+ro.build.characteristics=tablet
+
+# Workaround: Set the max_brightness of sprd_backlight to 1023
+persist.sys.qcom-brightness=1023
+
+# Workaround: Set the 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

system/usr/idc/goodix_ts.idc

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+# Copyright (C) 2010 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#
+# Input Device Configuration File for the Stingray touch screen.
+#
+
+# Basic Parameters
+touch.deviceType = touchScreen
+touch.orientationAware = 1
+touch.orientation = ORIENTATION_90
+
+## Size
+#touch.size.calibration = area
+#touch.size.scale = 28
+#touch.size.bias = 0
+#
+## Pressure
+#touch.pressure.calibration = amplitude
+#touch.pressure.scale = 0.0125
+#
+## Orientation
+#touch.orientation.calibration = none

vendor/etc/sensor_config.xml

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+  <root>
+  <!-->
+  sensor id 0
+  <-->
+      <CameraModuleCfg>
+        <SlotId>0</SlotId>
+        <SensorName>hi846</SensorName>
+        <Facing>BACK</Facing>
+        <Orientation>0</Orientation>
+        <Resource_cost>0</Resource_cost>
+        <VCM>
+            <AfName>dw9714</AfName>
+            <Mode>2</Mode>
+        </VCM>
+        <OTP>
+            <E2prom>
+                <OtpName>general</OtpName>
+                <I2cAddr>0xa4</I2cAddr>
+                <E2promNum>0</E2promNum>
+                <E2promSize>8192</E2promSize>
+            </E2prom>
+        </OTP>
+        <TuningParameter>
+            <TuningName>hi846</TuningName>
+        </TuningParameter>
+      </CameraModuleCfg>
+      <CameraModuleCfg>
+        <SlotId>0</SlotId>
+        <SensorName>gc8034_rear</SensorName>
+        <Facing>BACK</Facing>
+        <Orientation>0</Orientation>
+        <Resource_cost>0</Resource_cost>
+        <VCM>
+            <AfName>dw9714</AfName>
+            <Mode>2</Mode>
+        </VCM>
+        <OTP>
+            <E2prom>
+                <OtpName>general</OtpName>
+                <I2cAddr>0xa4</I2cAddr>
+                <E2promNum>0</E2promNum>
+                <E2promSize>8192</E2promSize>
+            </E2prom>
+        </OTP>
+        <TuningParameter>
+            <TuningName>gc8034_rear</TuningName>
+        </TuningParameter>
+      </CameraModuleCfg>
+  <!-->
+  sensor id 1
+  <-->
+      <CameraModuleCfg>
+        <SlotId>1</SlotId>
+        <SensorName>hi846_front</SensorName>
+        <Facing>FRONT</Facing>
+        <Orientation>0</Orientation>
+        <Resource_cost>0</Resource_cost>
+        <OTP>
+            <E2prom>
+                <OtpName>general</OtpName>
+                <I2cAddr>0xa6</I2cAddr>
+                <E2promNum>0</E2promNum>
+                <E2promSize>8192</E2promSize>
+            </E2prom>
+        </OTP>
+        <TuningParameter>
+            <TuningName>hi846_front</TuningName>
+        </TuningParameter>
+      </CameraModuleCfg>
+      <CameraModuleCfg>
+        <SlotId>1</SlotId>
+        <SensorName>gc8034</SensorName>
+        <Facing>FRONT</Facing>
+        <Orientation>0</Orientation>
+        <Resource_cost>0</Resource_cost>
+        <OTP>
+            <E2prom>
+                <OtpName>general</OtpName>
+                <I2cAddr>0xa6</I2cAddr>
+                <E2promNum>0</E2promNum>
+                <E2promSize>8192</E2promSize>
+            </E2prom>
+        </OTP>
+        <TuningParameter>
+            <TuningName>gc8034</TuningName>
+        </TuningParameter>
+      </CameraModuleCfg>
+  </root>