added termux proot build strategy

README.md

@@ -30,6 +30,28 @@ sysbuild.sh
 ```
 
 
+## Building on Termux (Android)
+
+It is possible to build the system directly on an Android device using Termux and PRoot.
+
+1.  Clone this repository in Termux.
+2.  Run the setup script to install `proot-distro`, `debian`, and build dependencies:
+    ```bash
+    ./setup_termux.sh
+    ```
+3.  Enter the build environment (follow the instructions printed by the setup script):
+    ```bash
+    proot-distro login debian --bind ".:/root/LinuxFromScratch" --cwd /root/LinuxFromScratch
+    ```
+4.  Proceed with the build as usual inside the PRoot environment:
+    ```bash
+    ./set_env.sh [TARGET_NAME]
+    sysbuild.sh
+    ```
+
+Note: Generating the SD card image (`init_sd.sh`) inside Termux is not supported due to lack of root privileges and loop device support. You can copy the generated `root-fs` to a PC to create the image.
+
+
 ## Usage
 
 To setup the build environnement run from the repository root folder

scripts/setup_proot_env.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+# Install dependencies inside PRoot (Debian/Ubuntu)
+
+# Update package lists
+apt update
+
+# Install build dependencies
+apt install -y build-essential git wget bzip2 file bc unzip rsync python3 cpio libncurses-dev gawk bison flex texinfo patch gzip perl sed tar diffutils grep coreutils make libssl-dev zlib1g-dev libelf-dev
+
+echo "Dependencies installed."

setup_termux.sh

@@ -0,0 +1,42 @@
+#!/data/data/com.termux/files/usr/bin/bash
+
+# Check if running in Termux
+if [ -z "$TERMUX_VERSION" ]; then
+    echo "This script is intended for Termux environment."
+    exit 1
+fi
+
+echo "Setting up Termux build environment..."
+
+# Check if proot-distro is installed
+if ! command -v proot-distro &> /dev/null; then
+    echo "Installing proot-distro..."
+    pkg install -y proot-distro
+fi
+
+# Install debian if not already installed
+# proot-distro install checks if it is installed, so we can just run it.
+# However, to avoid redownloading/checking every time if it takes long, we can check.
+if ! proot-distro list | grep -q "debian (installed)"; then
+    echo "Installing Debian..."
+    proot-distro install debian
+else
+    echo "Debian is already installed."
+fi
+
+# Determine repo directory
+REPO_DIR=$(pwd)
+SCRIPT_PATH="/root/LinuxFromScratch/scripts/setup_proot_env.sh"
+
+echo "Installing dependencies inside PRoot environment..."
+# We bind mount the current directory to /root/LinuxFromScratch
+# Run the setup script using bash explicitly
+proot-distro login debian --bind "$REPO_DIR:/root/LinuxFromScratch" -- bash "$SCRIPT_PATH"
+
+echo "Setup complete."
+echo "To enter the build environment, run:"
+echo "proot-distro login debian --bind \"$REPO_DIR:/root/LinuxFromScratch\" --cwd /root/LinuxFromScratch"
+echo ""
+echo "Then inside the environment:"
+echo "./set_env.sh <target>"
+echo "sysbuild.sh"