Refactor first-boot documentation and scripts to enhance Chromium startup behavior. Update start-chromium.sh to prefer Wayland for better touch support and adjust fullscreen handling for both Wayland and X11 environments. Clarify CM4 EEPROM configuration in documentation to prevent conflicts with reTerminal DM display backlight. Improve user guidance on touch interactions in Chromium.

emmc-provisioning/cloud-init/first-boot.md

@@ -17,7 +17,7 @@ This script runs once on first boot via cloud-init (see `user-data-remote-gnss.e
 9. **reTerminal DM drivers** — Seeed repo clone and `reTerminal.sh`.
 10. **Re-apply splash** — Set `disable_splash=0`, Plymouth theme to `custom` only, `update-initramfs`.
 11. **Dark theme** — Set GTK dark theme for user `pi`: `~/.config/gtk-3.0/settings.ini` with `gtk-application-prefer-dark-theme=1` and `gtk-theme-name=PiXnoir` (Raspberry Pi OS dark theme).
-12. **CM4 EEPROM enable** — On CM4, `rpi-eeprom-update` is disabled by default. First-boot enables it by: adding `RPI_EEPROM_USE_FLASHROM=1` and `CM4_ENABLE_RPI_EEPROM_UPDATE=1` to `/etc/default/rpi-eeprom-update`; adding a `[cm4]` block to `config.txt` with `dtparam=spi=on`, `dtoverlay=audremap`, `dtoverlay=spi-gpio40-45`. After reboot, `rpi-eeprom-update -l` works and boot order can be set.
+12. **CM4 EEPROM enable** — On CM4, `rpi-eeprom-update` is disabled by default. First-boot enables it by adding `RPI_EEPROM_USE_FLASHROM=1` and `CM4_ENABLE_RPI_EEPROM_UPDATE=1` to `/etc/default/rpi-eeprom-update`. **No config.txt changes are needed** — `dtoverlay=audremap`/`dtoverlay=spi-gpio40-45` are for the flashrom method only and **must not be added** as they conflict with the reTerminal DM display backlight (GPIO13 PWM). The bootloader method (`pieeprom.upd`) is used instead.
 13. **Boot order** — If `rpi-eeprom-config` is available, set `BOOT_ORDER=0x21` (network first, then eMMC/SD). On CM4 first boot this may be skipped (EEPROM not yet enabled); a one-shot systemd service runs after reboot to set boot order once.
 14. **One-shots** — Download `set-rotation-once.sh` + `.desktop` from file server (wlr-randr for labwc). Wallpaper is set once via pcmanfm config during first-boot.
 15. **Reboot.**
@@ -70,11 +70,13 @@ Creates `/home/pi/.config/autostart` so that `.desktop` files placed there are s
 Downloads from `FILE_SERVER` (no local creation):
 
 - **`FILE_SERVER`** — Base URL for first-boot assets (default: `http://10.130.60.141:5000/files/first-boot`). All first-boot files are served from a **first-boot** subfolder on the file server. Change this if your server or path is different.
-- **`start-chromium.sh`** — Downloaded to `/home/pi/start-chromium.sh`, made executable (755), owned by `pi`. This script waits for the desktop, starts Chromium in kiosk mode (e.g. `--app=...`), and uses `wmctrl` to force fullscreen.
+- **`start-chromium.sh`** — Downloaded to `/home/pi/start-chromium.sh`, made executable (755), owned by `pi`. Waits for the desktop, then starts Chromium in fullscreen. When the session is Wayland (rpd-labwc), Chromium runs with `--ozone-platform=wayland` so **touch long-press produces right-click (context menu)** like the rest of the desktop; on X11 it falls back to `--ozone-platform=x11` and uses `wmctrl` to force fullscreen.
 - **`chromium-kiosk.desktop`** — Downloaded to `/home/pi/.config/autostart/chromium-kiosk.desktop`, mode 644, owned by `pi`. This autostart entry runs `start-chromium.sh` when `pi` logs in.
 
 Ensure the `.desktop` file on the server has `Exec=/home/pi/start-chromium.sh` (or the path you use on the device).
 
+**Touch in Chromium:** Long-press on the touchscreen to open the context menu (right-click). This works when Chromium runs as a Wayland client (default under rpd-labwc). If you ever run under pure X11, long-press may not trigger the context menu; in that case you can use **evdev-right-click-emulation** (see e.g. [evdev-right-click-emulation](https://github.com/PeterCxy/evdev-right-click-emulation)) to inject right-click on long-press at the input layer.
+
 ---
 
 ## Boot splash and wallpaper (single image from file server)
@@ -134,7 +136,7 @@ First-boot sets a dark GTK theme for user **pi** via **`~/.config/gtk-3.0/settin
 
 ## CM4: enable rpi-eeprom-update (for boot order)
 
-On **CM4**, first-boot enables `rpi-eeprom-update` by: (1) **`/etc/default/rpi-eeprom-update`**: **`RPI_EEPROM_USE_FLASHROM=1`**, **`CM4_ENABLE_RPI_EEPROM_UPDATE=1`**; (2) **config.txt** **`[cm4]`** block: **`dtparam=spi=on`**, **`dtoverlay=audremap`**, **`dtoverlay=spi-gpio40-45`**. After reboot, **`rpi-eeprom-update -l`** works. See: [usbboot](https://github.com/raspberrypi/usbboot/blob/master/Readme.md).
+On **CM4**, first-boot enables `rpi-eeprom-update` by setting **`RPI_EEPROM_USE_FLASHROM=1`** and **`CM4_ENABLE_RPI_EEPROM_UPDATE=1`** in **`/etc/default/rpi-eeprom-update`**. **No dtparams are added to config.txt.** `dtoverlay=audremap` and `dtoverlay=spi-gpio40-45` are only needed for the *flashrom* (direct SPI) update method — they **must not** be added because `audremap` remaps audio to GPIO12/13, which conflicts with the reTerminal DM display backlight PWM on GPIO13, causing a blank screen. The bootloader file method (`pieeprom.upd`) works without these overlays. See: [usbboot](https://github.com/raspberrypi/usbboot/blob/master/Readme.md).
 
 ## Boot order (network first, then eMMC/SD)