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Andor’s Trail is a free and open (FOSS) single player RPG for Android. Although still under heavy development, the game is already fully playable, and the world map, quests and story is very impressive, with more to come.
Recently, an updated beta version was released, with even more maps and quests. The game is available from the FOSS market f-droid.org, and Google’s Play Market.
Building the Android OS from source has caused me a bit of pain, so it was therefore a pleasant surprise to see just how easy the CyanogenMod team has made their install and update process. For the Nexus S, it boiled down to: Follow the instructions, any everything just works. Therefore these are just some background notes; for full details, see the CyanogenMod install page.
What is a bit confusing in the Android world, are all the obscure and redundant code names from everything from hardware, models, OS, firmware, versions, regions. The Google Nexus binary pages gives some hints, as does the Android build instructions. For the Nexus S, it is crucial to know that the alternative codename is “crespo”. Furthermore, it is useful know that it has a “HDPI” display, and comes in three variations: “GT-I9020 (Super AMOLED) and GT-I9023 (Super Clear LCD), each aimed at different markets. The SPH-D720 is the newer 4G version of the phone available in the US.” (Wikipedia). Also, the radio binaries have different codes, e.g. “XXKB3″. This then forms the “baseband version” code on the form “I9023xxkd1″, which can be found under Settings -> About phone.
CyanogenMod is just a layer on top of the Android OS, thus it’s tracking the Android versions. Here we are talking about “Gingerbread” for the 2.3.x series, and “Ice Cream Sandwich” (aka. ICS) for the 4.x versions. (Who comes up with all these useless names??) Although Google pushed Android 4 to certain Nexus S devices in December 2011, and CM 9 (which based on Android 4) have nightly builds for the “crespo”, their stable CM 7 is still at Android 2.3.7. In addition to the basic OS, you might also want the Google Apps, although, some of them might have to be downloaded from the Market (now renamed to “Play”) anyway.
So, with that out of the way, and assuming the basic tools adb and fastboot in place (possibly from a previous build session), the upgrade can be summarized as this (with specific versions and URLs bound to change):
Download:
wget http://download.clockworkmod.com/recoveries/recovery-clockwork-5.0.2.0-crespo.img
wget http://download.cyanogenmod.com/get/update-cm-7.1.0.1-NS-signed.zip
wget http://cmw.22aaf3.com/gapps/gapps-gb-20110828-signed.zip
Flash the recovery image:
adb reboot-bootloader
sudo fastboot flash recovery recovery-clockwork-5.0.2.0-crespo.img
sudo fastboot reboot
Copy the CM files to the “sdcard” of the phone:
adb push update-cm-7.1.0.1-NS-signed.zip /sdcard/update.zip
adb push gapps-gb-20110828-signed.zip /sdcard/gapps.zip
adb reboot-bootloader
Follow the install instructions from CM for the rest. I was surprissed to learn that the data on the SD card was not wiped as well (I thought “Wipe data/factory reset” would take care of this). However, maybe I missed a step.
Following the list from yesterday, here’s more useful Android apps, this time both from the F-Droid and Android Market (aka. Play). First from F-Droid (APK file):
And from the Android / Google Play Market
Finally, there’s a few which can, or have to, be downloaded from the creator’s web site:
The Pirate Party of Canada has a nice list of applications and add-ons for Android phones which enhance security and privacy. It boils down to
The Replicant project was covered by Computer World today, with an interview of one of the main developers Paul Kocialkowski. The article was also picked up by Slashdot, where the mod was more cynical. Kocialkowski talked about the importance of free hardware and software when communicating in an insecure environment, and the difficulty of implementing an alternative when many of the drivers and firmware for key hardware is proprietary and secret.
Currently, Replicant is only supported by a few phones, including HTC Dream, Nexus One and Nexus S. The last one is probably interesting, as it is still a reasonably modern phone, can run Android 4.0, and have “factory binaries” available so you can start from scratch if you get stuck.
However, as pointed out in the Slashdot comment above, this project will always trail Google’s releases. And as we’ve seen previously, the source codes does not always follow the release of the OS. Furthermore, Android in itself is not the most exciting OS around. The MeeGo (and presumably Tizen) initiatives are more standard GNU/Linux distributions from the get-go. Including features we’ve taken for granted over the last ten years or more: dependency resolving, updates over repositories, GNU applications. Of course, these will struggle with exactly the same problem: the proprietary drivers.
After successfully building the Android OS, and flashing to the Galaxy Nexus, I’ve started investigating how it all hangs together. Starting with the boot.img, and unpacking the parts; header, kernel, and ramdisk. The structure is explained in detail on the Wiki android-dls.com, but also in the source for building the boot.img file.
As mentioned on the Wiki, and seen in the source, the page size can be 2048 or 4096 bytes, with the former the default. The header, which is rather boring, containing only a “magic string” (”ANDROID!”) and a checksum takes up the first page of 2048 bytes. It can be separated from a boot.img with the following command:
dd bs=2048 if=boot.img of=header count=1
Next up is the kernel. I’ve yet to find a way to determine its size, however you could go looking for white space padding and then round up to the nearest 2048 bytes. (Also, magic bytes (1F 8B) of the gzipped ramdisk will provide a clue.) In my case, I “cheated” and looked at the size of the kernel file under out/target/product/maguro. It turned out to take 1912 pages, so we can separate it by the following command (skipping the header part):
dd bs=2048 if=boot.img of=kernel skip=1 count=1912
Then it’s only the ramdisk filesystem left (there’s no “second stage” section in use). It will take the rest of the size of the file, which came down to 158 pages in my case:
dd bs=2048 if=boot.img of=ramdisk skip=1913 count=158
The ramdisk is a gziped, cpio packed archive, which can be extracted into its own directory by
mkdir ram
cd ram
gunzip -c ../ramdisk | cpio -i
That should give you the following files and directories
./init.rc
./ueventd.tuna.rc
./init.omap4pandaboard.rc
./res
./res/images
./res/images/charger
./res/images/charger/battery_4.png
./res/images/charger/battery_5.png
./res/images/charger/battery_1.png
./res/images/charger/battery_charge.png
./res/images/charger/battery_2.png
./res/images/charger/battery_fail.png
./res/images/charger/battery_0.png
./res/images/charger/battery_3.png
./init.tuna.usb.rc
./ueventd.goldfish.rc
./dev
./init.tuna.rc
./init.goldfish.rc
./init
./system
./data
./sys
./ueventd.rc
./sbin
./sbin/adbd
./sbin/ueventd
./proc
./charger
./default.prop
For more about the Android boot process, and kernel, look at the Embedded Linux Wiki.
As seen from the files above, the charger icons displayed when the phone is charging while off is plain PNG images. Might be fun to change. Furthermore, the initial splash screen logo can be changed by adding a file called initlogo.rle to the root directory of the ramdisk. Might try that next.
Here’s a brief command-by-command guide to building Android 4 (ICS -Ice Cream Sandwich (with extra sugar on top)) from scratch, and deploying the new images on the Samsung Galaxy Nexus, all from Fedora 16. This is heavily based on the Free your Android article, and of course the instructions at android.com.
First, install the supporting packages. (Instead of the OpenJDK version, you might have to download the Oracle one, if you get version conflict errors at the make step below.)
yum groupinstall "Development Tools"
yum install java-1.6.0-openjdk kernel-devel git gnupg flex bison gperf zip curl zlib-devel glibc-devel glibc-devel.i686 ncurses-devel.i686 glib-devel.i686 libstdc++.i686 zlib-devel.i686 ncurses-devel.i686 libX11-devel.i686 libXrender.i686 libXrandr.i686 mesa-libGL-devel.i686 readline-devel.i686 arm-gp2x-linux-gcc-c++ python-markdown xmlto libxslt
Download the source. The final sync command will take about an hour.
curl https://dl-ssl.google.com/dl/googlesource/git-repo/repo > ~/bin/repo
chmod a+x ~/bin/repo
mkdir android
cd android
repo init -u https://android.googlesource.com/platform/manifest
repo sync
Download proprietary binaries and drivers. They are available here:
http://code.google.com/android/nexus/drivers.html
Assuming the Galaxy Nexus – GSM/HSPA+ (”maguro”), there’s two drivers. (Please check the link above for new versions).
wget https://dl.google.com/dl/android/aosp/imgtec-maguro-iml74k-a796ffae.tgz
wget https://dl.google.com/dl/android/aosp/samsung-maguro-iml74k-de1cc439.tgz
tar zvxf imgtec-maguro-iml74k-a796ffae.tgz
tar zvxf samsung-maguro-iml74k-de1cc439.tgz
extract-imgtec-maguro.sh
extract-samsung-maguro.sh
Build, still assuming the same phone as above. On my somewhat dated dual core 2.6 GHz CPU, it took almost four hours to compile.
source build/envsetup.sh
lunch full_maguro-eng
make -j4
Then, transfer the image files to the phone. Make sure the phone is connected over USB, is unlocked, and has USB debugging enabled. After the images are transferred, and the userdata and cache partitions are erased, the phone will reboot. It will show the Android logo, reboot one ore two times more, and then wait maybe a minute or two before the UI is available. And there it is, your home-built Android OS.
out/host/linux-x86/bin/adb reboot bootloader
sudo out/host/linux-x86/bin/fastboot -w -p maguro flashall
If something, or everything, failed and you are left with a useless phone, here are the factory images from Google. Download and unpack the archive corresponding to your phone, and run the script
flash-all.sh
For more details on “unbricking” your phone, see Derek Ross’ comment.
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