Bash script to make BLOAD format .bin file of MSX from a binary file

msxbin.sh

#!/bin/bash
# -*- coding: utf-8-unix -*-

# Usage: msxbin.sh FILE BASE RUN
#   Outputs BSAVE header followed by contents of the given FILE to stdout.
#
#   - FILE :: input file name of the memory image
#   - BASE :: base address where the memory image would to be loaded
#   - RUN  :: entry point address of the memory image that shall be run by "BLOAD ..., R" command

size=$(stat -c '%s' $1)
beg=$(($2))
end=$((beg + size - 1))
run=$(($3))

printf '\xfe'
printf $(printf '\\x%02x\\x%02x' $((beg % 256)) $((beg / 256)))
printf $(printf '\\x%02x\\x%02x' $((end % 256)) $((end / 256)))
printf $(printf '\\x%02x\\x%02x' $((run % 256)) $((run / 256)))
cat $1

To make foo.bin from a binary file foo.dat on Ubuntu and so on:

msxbin.sh foo.dat 0x8000 0x9000 > foo.bin

Then, on MSX, BLOAD "foo.bin",R loads the file contents at address 0x8000 and runs from 0x9000.