Wrote a script that can take hexadecimal bytes from a file and write them to an output file and an sd card.

linux/sdcard/write-bytes.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+
+# This file writes a bunch of bytes to the flash card based on a text
+# file input with bytes written in hexadecimal.
+
+INPUTFILE=""
+OUTPUTFILE=""
+
+ARGS=()
+while [ $OPTIND -le "$#" ] ; do
+    if getopts "hi:o:" arg ; then
+        case "${arg}" in
+            h) help
+               ;;
+            i) INPUTFILE=${OPTARG}
+               ;;
+            o) OUTPUTFILE=${OPTARG}
+               ;;
+        esac
+    else
+        ARGS+=("${!OPTIND}")
+        ((OPTIND++))
+    fi
+done
+
+SDCARD=${ARGS[0]}
+
+if [ ! -e $INPUTFILE ] ; then
+    echo -e "Error: Input file $INPUTFILE does not exist."
+    exit 1
+fi
+
+if [ -e $OUTPUTFILE ] ; then
+    echo -e "Error: Output file $OUTPUTFILE already exists."
+    exit 1
+fi
+
+for word in $(cat "$INPUTFILE")
+do
+    echo -en "\x$word" >> $OUTPUTFILE
+done
+
+dd if=$OUTPUTFILE of="$SDCARD"