# Nokia S40 filesystem SMS format

This text is work in progress and does not claim to be correct or accurate. It is solely based on Gammu dumps received from users. Analysed by Michal Cihar <michal@cihar.com>.

## File structure

- 176 bytes header

    - at offset 7 is length of PDU data

    - at offset 94 is stored remote number in unicode

    - rest is not known

- PDU data (without SMSC)

    - here can be sometimes also some failure block, which is not known yet

- structured data header: 0x01 0x00 <LEN>, where <LEN> is length of rest

- structured blocks:

Block: <TYPE = byte> <LENGTH = word> <DATA …>

## Blocks

0x01

  Unknown x00 / x01 (maybe received / sent)

0x02

  SMSC number, ASCII

0x03

  Text, unicode

0x04

  Sender, unicode

0x05

  Recipient, unicode

0x06

  Unknown x00x00x00x00

0x07

  Unknown x00

0x08

  Unknown x02 / x00

0x09

  Unknown x00x00x00x00

0x0a

  Unknown x00

0x0b

  Unknown x00

0x0c

  Unknown, several values (maybe message reference per number)

0x0d

  Unknown x00x00

0x0e

  Unknown x00x00

0x0f

  Unknown x00x00

0x22

  Unknown x00

0x23

  Unknown x00x00x00x00

0x24

  Unknown x00

0x26

  Unknown x00

0x27

  Unknown x00

0x2a

  Unknown x00

0x2b

  some text (Sender?), unicode

To test:

  - multiple recipients sms