logisimage

#!/bin/sh

if [ "$#" -lt "1" -o "$#" -gt "2" ]
then
	cat <<-tac
		USAGE: `basename "$0"` <RISC-V executable> [Logisim memory image]

		Convert a RISC-V executable into a Logisim memory image.

		Makes the following simplifying assumptions:
		 * The .text entry appears first in the executable's section table.
		 * The .text section begins with the _start symbol, because we ignore entry point metadata.
		 * The addresses of all loadable sections are sequential, but not necessarily consecutive.
		 * Any non-loadable sections appear after all loadable sections, because we load everything.
		 * There are no hardcoded absolute addresses, because we place .text at the start of memory.
	tac
	exit 1
fi

if [ "$#" -eq "2" ]
then
	exec >"$2"
fi

echo "v2.0 raw"
riscv32-objdump -s "$1" | grep "^ " | cut -d" " -f2-6 | while read line
do
	address="`echo "$line" | cut -d" " -f1`"
	if [ -n "$lastaddr" ]
	then
		missing="$((0x$address - 0x$lastaddr - lastsize))"
		[ "$missing" -gt "0" ] && echo "$missing*00"
	fi
	lastaddr="$address"

	data="`echo "$line" | cut -d" " -f2- | tr -d " "`"
	echo "$data" | sed 's/../ &/g' | tail -c+2
	lastsize="$(($(printf %s "$data" | wc -c) / 2))"
done