Remove obsolete eMMC provisioning scripts and documentation for reTerminal DM4, including udev rules, flash trigger scripts, and related guides.

chromium-setup/emmc-provisioning/scripts/install-usbboot-on-host.sh

@@ -1,15 +1,20 @@
 #!/usr/bin/env bash
 # Run on the Proxmox HOST (root) when the host has internet.
 # Builds usbboot (rpiboot) and installs to /opt/usbboot so the auto-flash can run.
+# If the host has no internet, run build-and-deploy-usbboot-to-host.sh from your Fedora machine instead.
 
 set -e
 apt-get update
-apt-get install -y libusb-1.0-0-dev git
+apt-get install -y libusb-1.0-0-dev git pkg-config build-essential
 cd /tmp
 rm -rf usbboot
-git clone --depth=1 https://github.com/raspberrypi/usbboot
+git clone --recurse-submodules --shallow-submodules --depth=1 https://github.com/raspberrypi/usbboot
 cd usbboot
 make
 mkdir -p /opt/usbboot
 cp rpiboot /opt/usbboot/
+# Copy gadget dir(s) so rpiboot -d works
+for dir in mass-storage-gadget64 mass-storage-gadget; do
+  [[ -d "$dir" ]] && cp -a "$dir" /opt/usbboot/
+done
 echo "usbboot installed at /opt/usbboot/rpiboot"