[script] remove usage of sudo from bootstrap

script/bootstrap

@@ -41,14 +41,29 @@ script_dir="$(realpath "$(dirname "${script_path}")")"
 repo_dir="$(dirname "${script_dir}")"
 
 # ==============================================================================
+# Fancy red-colored `error` function with `stderr` redirection with `exit`.
+error()
+{
+    {
+        printf '\E[31m'
+        echo "$@"
+        printf '\E[0m'
+    } >&2
+    exit 1
+}
 
 install_packages_apt()
 {
+    # Test for root user.
+    if [ "$EUID" -ne 0 ]; then
+        error "Please re-run this script as root or with sudo"
+    fi
+
     echo 'Installing script dependencies...'
 
-    # apt-get update and install dependencies
-    sudo apt-get update
-    sudo apt-get --no-install-recommends install -y \
+    # Install dependencies
+    apt-get update
+    apt-get --no-install-recommends install -y \
         coreutils \
         openjdk-17-jre \
         python3-setuptools \
@@ -146,8 +161,10 @@ install_arm_toolchain()
     # Extract
     tar xf "${toolchain_dir}/${tarball}" --directory "${toolchain_dir}/${extract_dir}" --strip-components=1
 
-    # Link
-    sudo ln -s -f "${toolchain_dir}"/"${extract_dir}"/bin/* /usr/local/bin/
+    # Link if root
+    if [ "$EUID" -eq 0 ]; then
+        ln -s -f "${toolchain_dir}"/"${extract_dir}"/bin/* /usr/local/bin/
+    fi
 
     # Cleanup
     rm -rf "${toolchain_dir:?}/${tarball:?}"