傳統上，sensor要更新軟體 (特別是OS) 的方法，和一般的embedded system一樣，就是接上JTAG cable，將新版的軟體燒錄進senor的Flash ROM裡。不過因為senor通常是被放置在難以回收的地方，而且數量極為龐大，所以更新軟體往往是不可能的。我們實驗室最近有一個和工研院合作的計畫，是針對這個問題，要讓senor能夠自行透過無線網路做軟體更新，使用的平台是工研院提供的sensor–SCAN。

我們在SCAN上面寫了一個bootloader，由bootloader來負責OS更新的動作，無線網路的部份是使用SCAN內建的Bluetooth。在這個系統中，senor會定期的向後端的server詢問是否需要更新，一旦有新版的OS之類的情況，server會把新版和舊版OS差異的部份傳送給sensor，sensor再利用server傳送過來的資料重建起新版的OS。這篇論文是這整個計畫的其中一部分，包含了bootloader以及bootloader上的Bluetooth驅動程式。

Traditionally, if we want to update the software (especially OS) of a sensor, we have to attach JTAG cable to the sensor and write the new version of software to the Flash ROM of the sensor – same as usual embedded systems. But since sensors are often placed in hard-to-reached locations with huge amount, updating the software of sensors becomes mission impossible. There is a project cooperating with ITRI in our lab recently. The goal of the project is to make the software updating on sensors easier. The platform of the project we use is SCAN – the sensor developed by ITRI.

We implemented a bootloader on SCAN. The bootloader takes care of the OS updating. The wireless network on SCAN is Bluetooth, so we implemented the Bluetooth driver on the bootloader. In this system, the sensors will periodically check if updating is necessary. If it is, the backend server will transmit the difference between new and old versions of OS. The bootloader then rebuild the new version OS. This thesis is part of the project and including the bootloader and the Bluetooth driver on the bootloader.

[1] Bluetooth Specification Version 1.1
http://www.bluetooth.org/spec
[2] ZigBee
http://www.zigbee.org/
[3] IEEE 802.15 Wireless Personal Area Network Working Group
http://www.ieee802.org/15/
[4] Das U-Boot – Universal Bootloader
http://sourceforge.net/projects/u-boot
[5] BlueZ, Official Linux Bluetooth Protocol Stack
http://www.bluez.org/
[6] IEEE 802.11 Wireless LAN Working Group
http://grouper.ieee.org/groups/802/11/
[7] BlueCore Serial Protocol (BCSP), Cambridge Silicon Radio Limited, July 2004
http://www.csrsupport.com/download/540/BlueCore%20Serial%20Protocol%20%28bcore-sp-012Pb%29.pdf
[8] BCSP Channel Allocation, Cambridge Silicon Radio Limited, July 2004
http://www.csrsupport.com/download/416/BCSP%20Channel%20Allocation%20%28bcore-sp-007Pb%29.pdf

[9] BCSP Link Establishment Protocol, Cambridge Silicon Radio Limited, July 2004
http://www.csrsupport.com/download/417/BCSP%20Link%20Establishment%20Protocol%20%28bcore-sp-008Pb%29.pdf