kotlin-nds/me.nathanfallet.nds/NdsRom

NdsRom

Parses, mutates, and repacks a Nintendo DS ROM image.

NDS ROM binary layout (little-endian): 0x000 – 0x1FF header (512 bytes) arm9RomOffset ARM9 binary arm7RomOffset ARM7 binary fntOffset File Name Table fatOffset File Allocation Table (8 bytes per file: start u32, end u32) arm9OvlOffset ARM9 overlay table (32 bytes per entry) arm7OvlOffset ARM7 overlay table (32 bytes per entry) iconOffset Icon/title banner (file data at offsets recorded in FAT)

Types

Companion

object Companion

Properties

arm7

val arm7: ByteArray

ARM7 binary (sound/wireless co-processor code, loaded at the address given in the ROM header).

arm7Overlays

val arm7Overlays: List<ByteArray>

Raw file data for each ARM7 overlay, in overlay-table order. Index 0 corresponds to the first entry in the ARM7 overlay table.

arm7OverlayTable

val arm7OverlayTable: ByteArray

Raw bytes of the ARM7 overlay table (32 bytes × N entries). Use arm7Overlays to access individual overlay data by index.

arm9

val arm9: ByteArray

ARM9 binary (the main game code, loaded at the address given in the ROM header).

arm9Overlays

val arm9Overlays: List<ByteArray>

Raw file data for each ARM9 overlay, in overlay-table order. Index 0 corresponds to the first entry in the ARM9 overlay table.

arm9OverlayTable

val arm9OverlayTable: ByteArray

Raw bytes of the ARM9 overlay table (32 bytes × N entries). Use arm9Overlays to access individual overlay data by index.

banner

val banner: ByteArray

Icon/title banner block, or an empty array if the ROM carries no banner.

files

val files: Map<String, ByteArray>

All files in the ROM filesystem, keyed by virtual path (e.g. "a/0/3/2").

gameCode

val gameCode: String

Four-character game code read from header bytes 0x0C–0x0F (e.g. "IPKE").

gameTitle

val gameTitle: String

Game title read from header bytes 0x00–0x0B, with trailing NUL characters stripped.

rawHeader

val rawHeader: ByteArray

Raw 512-byte ROM header; offset fields are recalculated during pack.

Functions

pack

fun pack(): ByteArray

Serialises the (possibly modified) ROM back to a byte array.

withArm7

fun withArm7(data: ByteArray): NdsRom

Returns a new NdsRom with the ARM7 binary replaced by data. The original instance is unchanged.

withArm7Overlay

fun withArm7Overlay(index: Int, data: ByteArray): NdsRom

Returns a new NdsRom with the ARM7 overlay at index replaced by data. The original instance is unchanged.

withArm9

fun withArm9(data: ByteArray): NdsRom

Returns a new NdsRom with the ARM9 binary replaced by data. The original instance is unchanged.

withArm9Overlay

fun withArm9Overlay(index: Int, data: ByteArray): NdsRom

Returns a new NdsRom with the ARM9 overlay at index replaced by data. The original instance is unchanged.

withFile

fun withFile(path: String, data: ByteArray): NdsRom

Returns a new NdsRom with the filesystem file at path replaced by data. If path does not exist in the original ROM this call has no effect on the packed output. The original instance is unchanged.

withFiles

fun withFiles(updates: Map<String, ByteArray>): NdsRom

Returns a new NdsRom with multiple filesystem files replaced at once. Keys in updates that do not exist in the original ROM are silently ignored. The original instance is unchanged.