Peterism » android

A Little Primer on Bootloaders, Encryption, and Signing

Peter — Fri, 27 May 2011 17:20:13 +0000

A tweet from #AndroidPolice on Android booloaders and the security mechanism around it came to me through #cyanogen today. While it’s not meant to be comprehensive, I think it does help point developers and modders in the right direction to understanding come fundamental building blocks in information security. The fact that these security circumvention techniques float about on the Net goes to show that although the underlying encryption schemes and ciphers remain intact, hackers have consistently managed to find attack vectors that “side step” these measures, hence the term “circumvention”. It’s a proverbial game of cat and mouse perhaps calculated to cost-effectively block a majority of users while appeasing to script kiddies and modders alike. Link to the post on Android Police here.

[ROM] Baked Snack 1.8 for HTC EVO 4G (Supersonic)

Peter — Mon, 04 Oct 2010 07:20:28 +0000

Android Froyo based ROM for the HTC EVO 4G by Hero_Over.

You can find more information at the official Baked Snack site. I’m helping Hero_Over to make his awesome ROMs more accessible via Koush‘s ROM Manager, and will be updating ROM Manager as Hero_Over makes his public release.

If you have upgrade to ROM Manager Premium, you can also take advantage of the new “Web Connect” feature. Here’s the direct download link that takes advantage of Cloud to Device Messaging (C2DM):
Baked Snack 1.8 Froyo ROM for EVO 4G

Enjoy!

Android Phone Recorder Problem

Peter — Wed, 07 Jul 2010 00:25:43 +0000

Note: I don’t have time to complete this posting right now, so it’s in a draft format. I just wanted to briefly document my findings before I forget. Back to studying for the Patent Bar…

I finally pony up the Benjamins and got myself an Android handset, wait for it – the Sprint HTC EVO 4G!

You may not share my enthusiasm, but finally ditching my HTC Mogul (running WinMo 6.1) and moving into an even more open platform opens up a lot of possibilities for me. I’ve always been more comfortable developing on the *nix realm, and although I don’t have anything against the iPhone, Apple’s tight control on the iPhone OS just doesn’t sound that appealing to me. At this point in the mobile platform ecosystem, iPhone enjoys a almost 4-to-1 margin in the number of developers probably due to its two year head start in reaching the mainstream market, but the fact that Google opens up the entire Android platform, allowing me to develop apps that interface the hardware in a low-level way is much more appealing. I hope for a day when the mobile platform mimics the general purpose computers that makes it possible to run almost any OS on the same hardware.

A bunch of people have been having problem building a true phone recorder on the Android. Almost all smartphones these days come with an application processor (AP) and a baseband processor (BP). The BP is responsible for handling the radio, and voice encoding -decoding, among other related tasks. While the AP is used to run the OS and applications. The fact that despite having an API that supports recording voice call (both uplink and downlink), none have been able to successfully implement the feature suggests to me that there’s more than meet the eye. Upon further digging through the Android platform source and documentation, I found an interesting project within the platform that seems to be responsible for implementing what I want…, the Radio Interface Layer (RIL).

More to come…

Android 2.2 (Froyo) To Come with Tethering and Wifi Hotspot

Peter — Thu, 13 May 2010 18:02:05 +0000

I have been USB-tethering with my Sprint HTC Mogul for more than two years, connecting my Ubuntu 8.04~10.04 and Win XP~7 laptops/netbook to Sprint’s usually-speedy-enough 3G data network. While my Mogul still works fine as a phone, email client, light browsing, an GPS navigation with Tomtom 7 and Google Map, I am really getting tired of Windows Mobile 6.1.

I am a fan of building custom Linux kernels for the x84 architecture and having root access to an OS, so the ability to do (close to) the same on a ultra-portable embedded device with an ARM architecture with an Android OS appeals to me.

The hardware I want is something like the HTC Evo (4G) or the HTC Desire/Incredible. While the Android 2.1 that comes with them pretty much does what I need, and I think I can always tinker around to get USB or Wifi tethering, the rumor that Android 2.2 will come with that ability built-in gets me fired up. Sprint says they’ll be charging an additional $29.99/month for Wifi hotspot on the Evo, so it remains to be seen if a carrier will disable the new built-in Wifi hotspot capability so they can charge more.

If history is an indication of what’s to come, I may have a reason to be optimistic.

Back in October 2007 when I got my Mogul, rumors were that there was a GPS module built-in, but Sprint had disabled it in the ROM. A few months later, Sprint released a new ROM with that GPS module enabled, even though they continue to provide their proprietary Sprint Navigation at a monthly fee. I hope they somehow decide to allow the native Wifi hotspot, but I’m not holding my breath for it.