AT+i Programmer's Manual - SE Spezial-Electronic AG
AT+i Programmer's Manual - SE Spezial-Electronic AG
AT+i Programmer's Manual - SE Spezial-Electronic AG
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24 Remote Firmware Update<br />
24.1 Introduction<br />
Remote Firmware Update<br />
iChip accepts remote firmware updates from an HTTP or FTP server. The firmware<br />
update is stored as an .imz file on the host server and downloaded by iChip acting as a<br />
client. iChip replaces its existing firmware with the new one through a special application<br />
that is part of the .imz file. This method is especially convenient when managing<br />
firmware updates in a globally distributed install base of internet-enabled devices.<br />
24.2 Updating Firmware from a Remote Server<br />
This method involves placing the firmware update .imz file on an HTTP or FTP server.<br />
iChip has the provisions to use its respective HTTP or FTP client to download the<br />
firmware update file and perform the update process.<br />
Before the actual remote firmware update command can be issued, the following<br />
parameters must be set:<br />
USRV — Defines the protocol to be used (HTTP or FTP), and the name of the host<br />
on which one or more .imz files are stored.<br />
UUSR — Defines FTP user name (FTP only).<br />
UPWD — Defines FTP user password (FTP only).<br />
UEN — This flag indicates whether iChip updates to a firmware version that is newer<br />
than the currently installed one only, or to any firmware version it finds.<br />
In addition, an appropriate .imz firmware update file must be placed on the remote server<br />
at the location specified by the USRV parameter.<br />
Once the above parameters are defined, the firmware update process can be initiated by<br />
sending the following command to iChip:<br />
<strong>AT+i</strong>RFU<br />
iChip returns I/OK to acknowledge receipt of the command. As the update process may<br />
take up to 4 minutes to complete, iChip issues an I/UPDATE message to notify the host<br />
that it is in the process of updating its firmware. The host must allow for an extended<br />
delay period until iChip completes the process. Once completed, iChip re-boots the new<br />
firmware and issues an I/DONE message when in dialup mode, or an I/ONLINE in<br />
LAN mode.<br />
Several safeguards have been instated to ensure a successful firmware update. The<br />
firmware update file is structured by Connect One in a specific format, which allows<br />
iChip to authenticate its origin as a legal firmware image. iChip also verifies that the<br />
firmware update is the correct version for its hardware environment. iChip rejects an<br />
update file if it contains an image that is identical to the one already installed.<br />
The remote firmware update procedure is detailed below:<br />
1. iChip downloads the new firmware imz file.