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Comment: Re:Flashable? (Score 1) 123

by tap (#44377689) Attached to: The Rise of Linux In In-Vehicle Infotainment
If enough people want to hack it you can. There is nothing designed to help you flash it, but not a lot was done to actively stop it. The built in reflash system using a USB mass storage device is protected. Uses openssl. I didn't write that part so I don't know the details that well but I have this feeling it could be hacked with only a moderate level of 1337 skillz.

If you open it up, there is nothing stopping you from reprogramming the flash chips.

Comment: It's not Debian based (Score 5, Informative) 123

by tap (#44376823) Attached to: The Rise of Linux In In-Vehicle Infotainment
It's custom. I should know, as it's largely designed by me. I worked for Delphi who was the OEM that made the radios for GM. They didn't have any Linux experience, so I was hired for this project. They had lots of talented engineers who experience with VxWorks, QNX, uITRON, etc., but not POSIX/Linux. So I got them up to speed on Linux, helped designed the base OS, and made the Linux system work. I was told the Linux based software generated around $2 billion in sales. Then I got laid off.

It's based on Freescale's LTIB, which I also worked on when I worked for them. But, it's highly customized. Freescale hasn't really maintained LTIB for some time, despite continuing to use it as the base for their BSPs. Something like Debian is much too bloated for what the radios are expected to work it. The same system is used for the simpler non-touch radios in other GM vehicles. It's an ARM9 based iMX25, running at I think 380 MHz, with 32 MB of RAM. The framebuffer comes out of the RAM too. I managed to get it to boot from power on (or rather CAN bus wakeup pulse) through u-boot, through the kernel startup, to system startup and daemons running and have userspace application code start in around 250 ms. Getting the backup camera working in <1 second is an important requirement. The ARM9 as a VIVT cache, which forces a cache flush on each context switch, making it quite slow. If one used udev like a normal Linux distro, it takes something like 3 seconds just for udev to populate /dev on system startup. So obviously udev is out.

The radios are not designed to let you easily root or put different software on. However, stopping someone who has physical access to the radio from hacking it wasn't a very high priority. By default LTIB gives you a blank password root account and a telnet daemon configured to allow root logins! I got rid of that and made it ssh only. I don't know if the final production firmware still has ssh running or not. The iMX53 processor used in the CUE system doesn't have secure boot like some other iMX processors. Freescale's iMX line is actually composed of multiple utterly different families of ARM based SoCs based on different IP. So you can easily hack it with a flash programmer.

I don't know of any easter eggs.... GM isn't the kind of company that would look kindly on that. However, unless someone managed to fix it, you can lockup the DVD player with the "Justice League: Starcrossed" DVD a few minutes in. After the alien ship shoots at some jets. It's not the DVD player, but the video overlay on the iMX53 that has locked up.

Comment: Re:Tracphone (Score 1) 246

by tap (#42709827) Attached to: Ask Slashdot: Best Pay-as-You-Go Plan For Text and Voice Only?
I'm using tracfone too, since it's the cheapest I could find for minimal usage. The minutes are pretty cheap ( 10 cents), they don't expire, and the minimum monthly average you need to spend to keep you phone active is really low. But the SIMs and phones are locked. You can't use a normal SIM in a tracfone or a tracfone SIM in a normal phone. You can't even move tracfone SIMs between tracfones. The phone locks itself to the SIM it's first paired with.

Comment: Re:How long does it take to boot? (Score 1) 181

by tap (#41029401) Attached to: Tesla CTO Talks Model S, Batteries and In-car Linux
I'm a developer of Linux based car radios for a major OEM, so I'm getting a kick of of these replies. Linux can boot fast. A lot has to do with the hardware itself. Managed NAND can take a long time to initialize, SPI NOR flash has a low bandwidth, etc. The manufacturers are asking for things like 1 second boot time. A major concern is how it takes to get the back-up-camera working. I've managed to get a radio booting from POR to userspace in about 220 ms, and getting to done with Linux system startup by 500 ms. The leaves 500 ms for the application software to startup which was enough to meet the customer's requirements.

Porting Lemmings In 36 Hours 154

Posted by Soulskill
from the first-in-line dept.
An anonymous reader writes "Aaron Ardiri challenged himself to port his classic PalmOS version of Lemmings to the iPhone, Palm Pre, Mac, and Windows. The porting was done using his own dev environment, which creates native C versions of the game. He liveblogged the whole thing, and finished after only 36 hours with an iPhone version and a Palm Pre version awaiting submission, and free versions for Windows and Mac available on his site."

Comment: Re:What year is it for Voyager 1 & 2? (Score 1) 260

by tap (#32131978) Attached to: Voyager 2 Speaking In Tongues
You've taken into account special relativity, but there is also general relativity to take into account. Gravity slows time. Near the Earth's gravity time is slowed. For GPS satellites, their 3.9 km/sec speed slows their clocks by 7 us/day, but the reduced gravity at 20,000 km speeds their clocks relative the earthbound clocks by 45 us/day. So in that case the effect of gravity is greater than that of speed, and they gain time relative to us. Voyager 2 is going about 139 us/day slower than us due to it's speed. Once gravity is taken into account, I'd guess the result is somewhere around 82 us/day slower. Of course it's speed and the gravity it's experienced hasn't remained constant.

+ - HBO aquires rites to 'Song of Ice and Fire'

Submitted by jimfinity
jimfinity (849860) writes "HBO has picked up the rites to start a series based on George R. R. Martin's popular fantasy series 'Song of Ice and Fire.' From the article ( ategoryid=14&cs=1 ):

"The series will begin with the 1996 first book, "A Game of Thrones," and the intention is for each novel (they average 1,000 pages each) to fuel a season's worth of episodes. Martin has nearly finished the fifth installment, but won't complete the seven-book cycle until 2011."

Martin's journal ( also has some comments about the series."

All the simple programs have been written.