vipvop

A day or two ago someone posted a link to a great thread about hacking the nav system in the tsx, it mentioned that the DVD nav systems use Windows CE automotive. However I was looking to see if the 99 nav system uses Windows CE and found out that support for the SH4 processor (the chip in the DVD nav) was added to windows CE in 2000, so I'm guessing the 99 runs a different OS (a custom one?). Does anyone have information about the alpine unit that was similar to the '99, or the actual unit itself?

The thread of club tsx about hacking the navi:
http://www.clubtsx.com/bbs/showthrea...4&page=1&pp=15

vipvop

Well I found pics of the inside of the nav system but unfortunately all the chips are labeled alpine (including the CPU), so that's not much help. As soon as I get a USB network cable (to hook up the laptop to my desktop) I'm going to try and see if IDA will recognize the file as meant for an ARM, etc CPU. I don't think it will work but we'll see (IDA can disassemble programs meant for almost any CPU you'll find).

vipvop

Update: IDA couldn't disassemble the file. I heard somewhere else on the internet that the 99 nav system program was compiled using a metrowerks tool, assuming this is true it's almost guarenteed to be an ARM processor.

Nobody has looked into this already? Do the alpine engineers ever lurk on newsgroups or anything?

EnemyWithin

I found this site with some info about the 99 nav system.

fla-tls

Damn, those TSX are really getting into that navi system! Very cool thread...

vipvop

That guy had a good idea - take a compact flash card with a PCMCIA adapter and have your nav system not require a hard drive. Seeing as how hard drives don't like the heat of the trunk, and probably don't care for subs either, it should help your nav system last a while.

Back to the hacking the nav system news, I've been looking into the file APL.ALP on the hard drive. I'm guessing APL stands for "Application Program Loader" or something like that, my guess is it is the main boot code and that IKLA.ALP (or whatever the file is, don't have the list in front of me) is the main nav system program. Anyway, assuming the nav system is running on an ARM processor that means all instructions in assembly are 32 bits long. 32 bytes = 4 bytes, so if you open up the file in a hex editor each instruction will consist of 4 hex bytes.

I don't know if that is important or not (I've just started reading about ARM processors, and I also don't have experience in embedded systems) but I noticed the strings in the file APL.ALP all end on 32 bit boundaries. What I mean is lets say there's a string that says "No such file or directory" in the program. Strings in C end with 0x00, but in the nav system code since everything seems to need to be on 32 bit boundaries the string "No such file or directory" will have the inital 0x00 afterwords (making it 26 bytes long), then another 2 (to make the length an even multiple of 4 bytes, or 28 bytes long).

Now maybe this is common among all embedded software, or specific to the compiler used, but it seems like a promising sign that it is indeed an ARM processor inside the nav system.

EnemyWithin

Well I purchased the latest region 7 (NE) maps from that guy for $20. I also picked up a 512MB CF card+reader from Kingston. The speed increase using the CF card is impressive...I definately recommend it. If anyone needs the region 7 map files just let me know and I will get you a copy. Unlike some people, I won't charge

vipvop

Enemy - so the CF card is definitely faster? I was wondering about that, my hard drive is definitely about to go, I might have to try and replace it with a CF card.

I wonder if there are SD card to PCMCIA adapters, I have a 256 meg one for my (useless) pda...

EnemyWithin

It is definately much faster. It took around 50 minutes to transfer the 500MB of new map files onto the hard drive. That same transfer took under 10 minutes (around 8 minutes I think) with the CF card. The nav system is much more responsive with the CF card. Kingston has a good deal on the 512MB card and PCMCIA adapter combo for $106.