Usage

Usage: nessemble [options] <infile.asm>
                 <command> [args]

Options:
  -o, --output <outfile.rom>   output file
  -f, --format {NES,RAW}       output format
  -e, --empty <hex>            empty byte value
  -u, --undocumented           use undocumented opcodes
  -l, --list <listfile.txt>    generate list of labels and constants
  -p, --pseudo <pseudo.txt>    use custom pseudo-instruction functions
  -c, --check                  check syntax only
  -C, --coverage               log data coverage
  -v, --version                display program version
  -L, --license                display program license
  -h, --help                   print this message

Commands:
  init [<arg> ...]                 initialize new project
  scripts                          install scripts
  reference [<category>] [<term>]  get reference info about assembly terms
  config [<key>] [<val>]           list/get/set config info
  lsp                              run the language server (stdio)

The lsp command starts the built-in Language Server for use with LSP-capable editors.

Options

-o, --output <outfile.rom>

Sets the filename where output is written. An outfile of - (or omitting the flag) writes to stdout.

nessemble infile.asm --output outfile.rom

-f, --format

Specifies the output format:

• NES — an iNES ROM, complete with a 16-byte header.
• RAW — raw assembled 6502 code.

The format is RAW by default, but if iNES header directives (.inesprg, .ineschr, …) are present, it becomes NES unless overridden.

-e, --empty <hex>

Sets the fill value for empty/unwritten ROM bytes. Defaults to FF.

nessemble infile.asm --empty 00

-u, --undocumented

Allows the use of undocumented ("illegal") opcodes.

-l, --list <listfile.txt>

Writes a list of labels and constants to the given file.

-p, --pseudo <pseudo.txt>

Points to a mapping file that enables custom pseudo-instructions. See Extending.

-c, --check

Checks the input for syntax errors only; produces no output.

-C, --coverage

Reports per-bank ROM coverage. Only meaningful when the format is NES.

-v, --version / -L, --license / -h, --help

Print the version, license, or usage message respectively.

Commands

init [<arg> ...]

Scaffolds a new project, prompting for any values not supplied as arguments:

nessemble init [filename] [prg] [chr] [mapper] [mirroring]

• filename — file to create.
• prg / chr — number of PRG / CHR banks.
• mapper / mirroring — iNES mapper and mirroring.

scripts

Installs the bundled custom-pseudo-instruction scripts into ~/.nessemble/scripts. See Extending.

reference [<category>] [<term>]

Prints reference information from locally bundled data. With no arguments it lists the categories (instructions, directives); with a category it lists its entries; with a term it prints the details (e.g. reference instructions LDA).

config [<key>] [<val>]

Gets or sets configuration stored in ~/.nessemble/config. With no arguments it lists all keys; with a <key> it prints that value; with a <key> and <val> it sets the key.