[Upgrading, Modifying and Unlocking] yellowfever:
Flash GPS firmware on T830 / AGPS aka SirfInstantFix

Hi Guys,

I'm kinda new to this, so first of all thanks to everyone actively developing new stuff for the trusty old T830.

Well, as a thanks I want to give something back. I found out how to flash the GPS firmware, and I am working on getting AGPS to work on the T830. I am nowhere near finished, so stay tuned for updates.

So far I can confirm that the Loox N5xx's GPS firmware (GSW3.2.4Pat2_3.1.00.12-SDK001P1.00) works OK on the T830, and is indeed AGPS capable (unlike seemingly the original one as well as the 3.2.5 from Falcom, which also runs OK)

To test if the firmware really can use AGPS, I use SirfDemoPPC 1.16, older versions will seemingly not support SirfInstantFix:

http://www.usglobalsat.com/downloads/SiRFDemoPPC.zip

In this software you can load the extended ephemeris files available for example here:

http://service.mio-tech.com/eeservice/packedephemeris.ee

http://htcscm13.htc.com.tw/clm/packedEphemeris.ee

In the "signal" view you can see the satellites' bars turn pink if the satellite is being used by applying SirfInstantFix extended ephimeris data (as opposed to blue = not used for navigation and green = ephimeris from satellite broadcast).

For me, the fastest TTFF (time to first fix) seems to be like this:

In SiRFDemoPPC switch to Sirf Binary mode, load the .ee file, issue a warm start command, then some seconds later issue a hot start command. Strange...

As I said, I am still investigating. These are just my observations so far, and I won't stop investigating until I know for sure whats happening and why :)

My goal is to have the AGPS work as automatic as on the Loox N5xx. So far I don't see the COM port sharing to work at all on the T830, though, which would be necessary for the N5xx tool to provide the .ee data automatically and transparently in the background (instead of having the application that uses the GPS exclusively take care of this - as most navigation software doesn't have this capability).

UPDATE: How to get an almost usable Sirf Instant Fix is described here: http://xdaforums.com/showpost.php?p=3683425&postcount=1370

Please use the following description with extreme caution. It will ONLY update the GPS firmware. But: So far I have already bricked one T830 (for no apparent reason, after a few successful tries, update screen on the device just said "failed" and wants to update again at every start of the phone, won't boot, but the windows software used can't update "again"), so this way seems not 100% fool proof :( Luckily it was only a 2nd "spare" T830, and my main one is still available to test... so with many updates like this (maybe 20 or so) 1 failed... so be warned. I am sure it's possible to "un-brick" the failed T830, but you would need some software that can send the correct firmware to the updater on the phone...

UPDATE: Here you can get the complete firmware flash files, without any modification by yourself necessary: http://xdaforums.com/showpost.php?p=4236994&postcount=1458

- Get the official flash update from the manufacturer:

http://support.fujitsu-siemens.com/...B1C36E&Status=True&Component=Operating System

- Install on your windows PC

- Go to c:\fsc.tmp\PocketLOOX8xx\FlashUpdateV811

- edit os.lst (hidden file) to look like this:

+
<DGPS,3.5.0,0.1,undefined,undefined,undefined>
CN3.bin
-

in the 2nd line enter the version that you want to be shown in the update tool... not really any influence on how it works, so you can ignore it

In the 3rd line enter the file name of the .bin file BINARY firmware image. If you only have the .s s-record version of a firmware, you need to convert it to .bin BINARY first, using one of the million easily found converters on the net.

- Put the binary firmware file in the same directory

Download the 3.5.0 firmware for example here: http://xdaforums.com/showpost.php?p=3664766&postcount=1359

If you need to go back: The old original is here: http://xdaforums.com/showpost.php?p=3735151&postcount=1396

- Connect the T830 cradle to both AC adapter and laptop, must have an active sync link

(If you do NOT have a cradle, maybe this hint helps: http://xdaforums.com/showpost.php?p=1888017&postcount=86)

- Run the T830 software update like normally

- The T830 will go to new USB download mode, and will show that the flash was successful (hopefully) after it's done

- Do a reset after that, since the automatic reset at the end that the flash software expects doesn't work

- If you want an automatic FACTORY reset (lose all data, go back to defaults for everything at the end), use the following os.lst instead:

+
<DGPS,3.5.0,0.1,undefined,undefined,undefined>
CN3.bin
<RSTC,undefined,undefined,undefined,undefined,undefined>
POE.dum
-

So, now have fun with this knowledge that I discovered by simple trial and error after looking at the official flash update (that also updates other stuff besides the operating system) ;)

I will update once I have better understandings about AGPS, confirmed other firmwares working, or found a way to make AGPS run as easy as on Loox N5xx...

Now if anyone can help me update the firmware on an N100, I'd be one happy camper :D