chore: keep the tested factory firmware in firmware/ (CI only)

README.md

@@ -47,7 +47,7 @@ The fastest way to try an example is a ready-to-flash package from the
 4. Run `flash_combined.bat COMx` on Windows or `./flash_combined.sh /dev/ttyACM0` on Linux.
 5. Reset the board if it does not restart automatically.
 
-Factory firmware (restores the out-of-box demo): download the file whose name contains `FactoryOnly` from the [Releases page](https://github.com/waveshareteam/ESP32-S3-RLCD-4.2/releases).
+Factory firmware (restores the out-of-box demo): download the file whose name contains `FactoryOnly` from the [`firmware`](firmware/) folder.
 
 ## 🧪 Examples
 

README_ZH.md

@@ -45,7 +45,7 @@ ESP32-S3-RLCD-4.2 是一块 AIoT 开发板，采用 ESP32-S3-WROOM-1-N16R8 模
 4. Windows 运行 `flash_combined.bat COMx`，Linux 运行 `./flash_combined.sh /dev/ttyACM0`。
 5. 如果开发板未自动重启，请手动复位。
 
-出厂固件（恢复开箱演示）：在 [Releases 页面](https://github.com/waveshareteam/ESP32-S3-RLCD-4.2/releases)下载文件名带 `FactoryOnly` 的文件。
+出厂固件（恢复开箱演示）：在 [`firmware`](firmware/README_ZH.md) 目录下载文件名带 `FactoryOnly` 的文件。
 
 ## 🧪 示例
 

firmware/README.md

@@ -0,0 +1,17 @@
+# Firmware
+
+[English](README.md) | [简体中文](README_ZH.md)
+
+Ready-to-flash firmware tested on the ESP32-S3-RLCD-4.2 board. Each file is a merged image flashed at `0x0`; the date in the file name is its version.
+
+| File | Purpose |
+| --- | --- |
+| `ESP32-S3-RLCD-4.2_FactoryOnly_20260120.bin` | Factory firmware, restores the out-of-box demo |
+
+Flash with esptool:
+
+```bash
+python -m pip install esptool
+esptool.py --chip esp32s3 --port <PORT> erase_flash
+esptool.py --chip esp32s3 --port <PORT> write_flash 0x0 ESP32-S3-RLCD-4.2_FactoryOnly_20260120.bin
+```

firmware/README_ZH.md

@@ -0,0 +1,17 @@
+# 固件
+
+[English](README.md) | [简体中文](README_ZH.md)
+
+在 ESP32-S3-RLCD-4.2 开发板上实测过、可直接烧录的固件。每个文件都是从 `0x0` 烧录的合并镜像，文件名中的日期即版本。
+
+| 文件 | 用途 |
+| --- | --- |
+| `ESP32-S3-RLCD-4.2_FactoryOnly_20260120.bin` | 出厂固件，恢复开箱演示 |
+
+用 esptool 烧录：
+
+```bash
+python -m pip install esptool
+esptool.py --chip esp32s3 --port <PORT> erase_flash
+esptool.py --chip esp32s3 --port <PORT> write_flash 0x0 ESP32-S3-RLCD-4.2_FactoryOnly_20260120.bin
+```