Add script for aligning RP2040 binaries

Author: webhdx

tools/rp2040_4k_align.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+# -----------------------------------------------------------------------
+# rp2040_4k_align.sh - Aligns binary file size to 4KB multiples
+# -----------------------------------------------------------------------
+# Purpose: 
+#   Pads binary files to 4KB block size to work around an issue with 
+#   the RP2040 bootrom as described in the RP2040 datasheet errata section.
+#
+# Usage: 
+#   ./rp2040_4k_align.sh input_file output_file
+#
+# Arguments:
+#   $1 - Input file path
+#   $2 - Output file path
+#
+# Example:
+#   ./rp2040_4k_align.sh picoboot.bin picoboot_padded.bin
+# -----------------------------------------------------------------------
+
+dd if=/dev/zero of="$2" bs=1 count=$(( ($(stat -c%s "$1") + 4096 - 1) / 4096 * 4096 )) 2>/dev/null
+dd if="$1" of="$2" bs=1 count=$(stat -c%s "$1") conv=notrunc 2>/dev/null