BPM almost-documentation, scavenged off beat v03's source code

bpm.txt

signature "BPM1"

number metadata_len
string metadata

actions {
	// create directory with name `target_name`
	action 0: CreatePath | ((name_len - 1) << 2) {
		byte[] target_name
	}

	// create a file called `target_name` and fill it with `file_data`
	action 1: CreateFile | ((name_len - 1) << 2) {
		byte[] target_name
		number file_length
		byte[] file_data
		uint32 checksum
	}

	// apply BPS patch against `target_name`
	action 2: ModifyFile | ((name_len - 1) << 2) {
		byte[] target_name
		number origin
		number bps_length
		byte[] bps_file
	}

	// copy file `target_name` without modifications
	action 3: MirrorFile | ((name_len - 1) << 2) {
		byte[] target_name
		number origin
		uint32 checksum
	}
}

uint32 checksum