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>.

- 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 \x00\x00\x00\x00
0x07 - Unknown \x00
0x08 - Unknown \x02 / \x00
0x09 - Unknown \x00\x00\x00\x00
0x0a
0x0b - Unknown \x00
0x0c - Unknown, several values (maybe message reference per number)
0x0d
0x0e
0x0f - Unknown \x00\x00


0x22 - Unknown \x00
0x23 - Unknown \x00\x00\x00\x00
0x24 - Unknown \x00
0x26 - Unknown \x00
0x27 - Unknown \x00
0x2a - Unknown \x00
0x2b - some text (Sender?), unicode


To test:
    - multiple recipients sms
