add script to clean SD card before flashing U-Boot

.local/scripts/other-common-scripts/flash-only-uboot.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+
+set -xeuf -o pipefail
+
+DEVICE="$1"
+UBOOT="$2"
+DD_COMMON='dd conv=sync status=progress'
+
+if [[ "${EUID}" != '0' ]]; then
+    echo 'Run as root'
+    exit 1
+fi
+
+if [[  ! -f "${UBOOT}" ]]; then
+    echo "file not found: ${UBOOT}"
+    exit 2
+fi
+
+if [[ ! -b "${DEVICE}" ]]; then
+    echo "device not found: ${DEVICE}"
+    exit 3
+fi
+
+${DD_COMMON} bs=1M count=64 of="${DEVICE}" if=/dev/urandom
+sync
+${DD_COMMON} bs=1M count=64 of="${DEVICE}" if=/dev/zero
+sync
+
+if [[ -n "${3:-}" ]]; then
+    ${DD_COMMON} bs=512 seek=64 of="${DEVICE}" if="${UBOOT}"
+else
+    ${DD_COMMON} bs="$3" seek="$4" of="${DEVICE}" if="${UBOOT}"
+fi
+sync