depends what version of the rom you want
heres the dump info that might help you
x039 - New Super Mario Bros. (Europe) (En,Fr,De,Es,It) (Demo) (Kiosk).nds
ROM data
Size: 33554432
Decrypted CRC32: 77426AB2
Decrypted MD5: 346502918B4DB2A29D39A9A4B820316B
Decrypted SHA-1: F19EFD437F225ED7FBE42BB6ADC9284E7DBF3709
Encrypted CRC32: 08404C9D
Encrypted MD5: 8873374FB2ABE3BE120BC7CDE3B64540
Encrypted SHA-1: 85F58C1077CE00600A7553BEF2119E2A8C1AAEF0
Game Serial: A85P
x100 - New Super Mario Bros. (USA) (Demo) (Kiosk).nds
Size: 33554432
Decrypted CRC32: FEAB1381
Decrypted MD5: 6C81C918F09406D562E6331ABA24827A
Decrypted SHA-1: 812D26A6B6A519231D6FEB4D9C8F51DB992DB10F
Encrypted CRC32: 4C598365
Encrypted MD5: 3AD1675C5A655D43143B1202943817F5
Encrypted SHA-1: 60B20FA7A9003A9036B655751090C3A1266BD271
Game Serial: A85E
x168 - New Super Mario Bros. (Europe) (En,Fr,De,Es,It) (Demo) (Kiosk,Y78P).nds
Size: 33554432
Decrypted CRC32: 58B09C09
Decrypted MD5: 89A0C84E0B75B6506AEAFC4149B1C431
Decrypted SHA-1: CDEB4E97EA688EC2EBBC12856BCE72B071DE57D3
Encrypted CRC32: 27B2BA26
Encrypted MD5: 9B87D93F37D0D9FBACC0331B0D866794
Encrypted SHA-1: 597C3137F4DAD7D4A7871791CA21000E98A346B2
Game Serial: Y78P