Hello Android!

[ link: android-hello-world | tags: android g1 | updated: Thu, 20 Aug 2009 22:14:33 ]

I now have a sim-unlocked rooted T-mobile G1 phone running Android. I've installed the Cyanogen v3.6.8.1 firmware on it, and upgraded the recovery image to Cyanogen's pimped out version.

I am really impressed with the cell phone and MID aspects of the device. But I bought it so I could do some hacking.

All right... so what else can I do with this thing? It sounds logical that I now write a Hello world application.

Setting up build environment

Android apps are written in Java and run on a davlik virtual machine. I am still learning, but from what I understand it's a VM akin to the Java VM but more optimized for embedded devices and using completely incompatible bytecode.

After installing the SDK you will have an emulator and some development tools available in your PATH:

  • android - create and manage AVD (virtual devices) and projects
  • apkbuilder - build a package
  • ddms - a debugger for davlik VMs on emulated or real
  • dmtracedump - parser for trace files
  • draw9patch - tool for converting images into 9-region scalable ones
  • emulator - qemu based emulator
  • hierarchyviewer - interface design viewer tool
  • hprof-conv - don't know yet
  • mksdcard - create a disk image for the emulator
  • sqlite3 - everyone ships their own sqlilte3 binary :)
  • traceview - log viewer for debugging apps

Before building on Debian, I needed to install the following additional tools:

# apt-get install sun-java6-bin sun-java6-jdk ant ia32-libs

(the ia32-libs is only needed on 64 bit systems)

For whatever reason, I also had to set the JAVA_HOME environment variable like so:

export JAVA_HOME=/usr/lib/jvm/java-6-sun-1.6.0.14/

(without it, it complained that it was set to /usr/lib/jvm/ia32-java-6-sun-1.6.0.14/jre ... note that I just had to remove the jre from what it self detected)

Along with the tools the SDK comes with some activities and tutorials under platforms/android-1.5/samples/, but it's probably better to follow along with the online on line versions.

Building Hello World

I started by creating a new project:

# android create project --target 1 --path ./test1 --activity Test1 --package net.jukie.test1
# cd test1

I then made some changes to the src/net/jukie/test1/Test1.java app:

  • added import android.widget.TextView; at the top.
  • modified onCreate() to read:

    super.onCreate(savedInstanceState);
    TextView tv = new TextView(this);
    tv.setText("Hello, Android");
    setContentView(tv);
    

And, now to build the sucker:

# ant debug

That gives me a bin/Test1-debug.apk.

Next, I installed the app on my device using:

# adb install bin/Test1-debug.apk
87 KB/s (4468 bytes in 0.049s)
    pkg: /data/local/tmp/Test1-debug.apk
Success

Weee! My first useless app is now running on my Tmobile G1 displaying Hello, Android.

Debugging

Now that my app is running, let's connect a debugger to it. We will use the ddms tool to redirect a connection to the davlik VM running our process to a local socket. The ddms program assigns a unique port number for a debugger to connect to to each app (or each VM that runs the app). You can see that port in the top left pane of the ddms window. Selecting any application will two numbers in the right pane, in my case it's 8610 / 8700; the latter is assigned to the currently selected app. Let's use that.

From the directory in which your project was built, run:

# jdb -attach localhost:8700

You'll be greeted with a Java debugger prompt. You can now do things like manage breakpoints, inspect objects and thread state, and do other standard debugging things.

Being a C guy at heart, I always found it strange how thread-demanding Java is. The davlik VM seems to be no better:

> threads
Group system:
  (java.lang.Thread)0xc1436ec1e8 <7> Signal Catcher    cond. waiting
  (java.lang.Thread)0xc1427a7240 <5> HeapWorker        cond. waiting
Group main:
  (java.lang.Thread)0xc140019b48 <3> main              cond. waiting
  (java.lang.Thread)0xc1436ee610 <15> Binder Thread #3 running
  (java.lang.Thread)0xc1436ed8b8 <13> Binder Thread #2 running
  (java.lang.Thread)0xc1436ed400 <11> Binder Thread #1 running

... note that this is a Hello world program that doesn't actually do anything.

Anyway... that's enough for today.

Resources

Bart's Blog

/20090814131559

About

I am an embedded Linux software developer and consultant operating under Jukie Networks Inc in Ottawa, Canada.

RSS Feed - Full Content

RSS Feed - Full Content

ipv6 ready

Valid XHTML 1.0 Transitional

Created with Vim

Created with Perl




Tags

abiword adam android apt asm ata audio bacula bash bios board-game boot bug busybox bzr c code conference debian debug desktop devel disk dns dpkg dream email embedded find firefox font fs fun g1 gdb geode git git scm git-find git-graft go google gpg grub hardware html hw inkscape ion3 ipsec ipv6 ipv6summit.ca irc irssi joke kdb kernel klips kqemu kvm laptop lastfm ldap lighttpd linux lua lvm mail make mercurial meta mindblown mmc mouse-free mp3 mpd music mutt neovim net nexusone nfs nvim oclug ogre ols oom OOo openswan opteron osx ottawa perl photography power pxe qemu raid redhat rogers ruby sata sbc scm screen script scsi security sheeva shell skype spam squid ssd ssh suse svn tags talk thinkpad ubuntu uml unix urxvt usb uzbl vi video vim vimgit virt vpn vserver web weechat wifi wind wmii wmiirc-lua work x x86 x86emu xen xen-box-setup xfs xterm zsh

Posts

[ 20240214132102 ]
new git learnings

[ 20240203164450 ]
new vim config

[ 20181212145129 ]
improving find -exec efficiency

[ 20130409092758 ]
automount mmcblk devices

[ 20130316190507 ]
tunnelbroker vs IRC

[ 20110616180255 ]
HDD -> SDD

[ 20110517204617 ]
how to manually create a 6in4 tunnel

[ 20110501202915 ]
Presentation slides published!

[ 20110320190458 ]
What is IPv6, and why should I care?

[ 20110309230106 ]
Ottawa IPv6 Summit 2011

[ 20110309225149 ]
I am now an IPv6 Sage

[ 20101214145558 ]
It's a Holiday Miracle

[ 20101103095130 ]
ipv6 on your desktop in 2 steps

[ 20101020113026 ]
growing a live LVM volume

[ 20100915175649 ]
distributing DNS list through radvd

[ 20100908173402 ]
Canadian ipv6 drought

[ 20100903190623 ]
ipv6 certification

[ 20100723192259 ]
m4a to mp3

[ 20100723134522 ]
git 1.7.2 is out

[ 20100523092001 ]
console=ttyS0 with grub2

[ 20100426162644 ]
How many times is my function used within an executable?

[ 20100412100135 ]
vmlinux on Ubuntu

[ 20100328152951 ]
where your WIND coverage ends

[ 20100326113354 ]
Nexus One live in Ottawa on WIND Mobile

[ 20100311133411 ]
the WIND excitement

[ 20100302160743 ]
sata hotswap pico-HOWTO

[ 20100227093435 ]
serving http content out of a git repo

[ 20100225104049 ]
pimped out zsh prompt

[ 20100221184126 ]
live termcasting of your terminal over telnet

[ 20100215083725 ]
Debian on UBIFS upgrade on SheevaPlug

[ 20100214205532 ]
nexus one

[ 20100130150527 ]
skype on Debian Linux (64bit)

[ 20100125191021 ]
I am so peeved at Rogers

[ 20091205130455 ]
running really nice

[ 20091120225902 ]
notmuch for vim

[ 20091113102221 ]
squid and apt

[ 20091104195344 ]
using WIP branches to save every edit

[ 20091104194146 ]
using git workflows to avoid loosing intermediate changes

[ 20091019183503 ]
reflections on ACM Reflections

[ 20091013174248 ]
bacula rejected Hello command

[ 20091007235046 ]
pimping out git log

[ 20091002094400 ]
virtualization primer

[ 20090922110756 ]
adding an external encrypted volume under Debian

[ 20090905112529 ]
the dreaded process of rooting Rogers Dream

[ 20090830174551 ]
Cyanogen's recipe for Cupcake/Donut-like pastry

[ 20090827100232 ]
simpler android rooting

[ 20090821095427 ]
androids don't like water

[ 20090820215358 ]
prettier function tracing

[ 20090816151854 ]
Baking a cupcake

[ 20090814131559 ]
Hello Android!

[ 20090813100025 ]
sim unlocking a G1

[ 20090731185522 ]
rooting the droid

[ 20090727210307 ]
getting into android

[ 20090714094340 ]
importing an old project into git

[ 20090702113222 ]
Why pick Git?

[ 20090628131255 ]
select loop for X events

[ 20090625181315 ]
portable printf

[ 20090623225800 ]
switching to uzbl

[ 20090622223147 ]
Linux Symposium

[ 20090622214023 ]
bringing git-format-patch to bzr

[ 20090612215638 ]
nfs local caching with fscache and cachefilesd on Lenny

[ 20090610202041 ]
Scott Chacon smacks git around

[ 20090610150039 ]
how would you read a file into an array of lines

[ 20090609215141 ]
libguestfs

[ 20090609000208 ]
tiding up the PATH

[ 20090608232531 ]
only showing relevant messages in mutt by default

[ 20090608010405 ]
git-vim hacking

[ 20090530223801 ]
mark-yank-urls: fix bug allowing shell to interpret the url

[ 20090509212648 ]
wmiirc-lua v0.2.8 release

[ 20090509113125 ]
wmiirc-lua moving to github

[ 20090504101605 ]
two terminals one PWD

[ 20090501172645 ]
splitting files out of a commit

[ 20090409155905 ]
git workflow: git amend

[ 20090401112030 ]
how old are these files in git?

[ 20090330181138 ]
sles 11 on kvm

[ 20090323194942 ]
android true type font

[ 20090322203939 ]
popen with stdin, stdout, and stderr

[ 20090320214228 ]
shrinking URLs

[ 20090304004744 ]
readlater

[ 20081112150409 ]
splitting patches with git

[ 20081011081638 ]
creating busybox symlinks

[ 20081002215121 ]
wmiirc-lua v0.2.5 release

[ 20080916155113 ]
git-svn strangeness

[ 20080915112959 ]
installing git man pages quickly

[ 20080913112345 ]
wmiirc-lua v0.2.4 release

[ 20080825100454 ]
Kernel Walkthroughs - booting

[ 20080813210205 ]
Linux Kernel Booting

[ 20080719211329 ]
printable OLS/2008 schedule

[ 20080715214447 ]
wmiirc-lua updates

[ 20080713194704 ]
Git Screencast

[ 20080713143429 ]
four steps to reproducible Debian installs

[ 20080705150651 ]
USB2.0 enclosure benchmark

[ 20080703230924 ]
Linux Kernel Walkthroughs posted

[ 20080702113602 ]
Introducing the Ottawa Ruby folks to Git

[ 20080628160732 ]
Authenticating Linux against OSX LDAP directory

[ 20080627142123 ]
Canada Day Events 2008

[ 20080613162541 ]
Linux Kernel Walkthroughs

[ 20080510083828 ]
is my usb device connected to a fast port?

[ 20080509111534 ]
show more git info on zsh prompt

[ 20080430104202 ]
git-vim

[ 20080412100337 ]
color your word

[ 20080404105620 ]
show current git branch on zsh prompt (2)

[ 20080303200359 ]
how to track multiple svn branches in git

[ 20080301134220 ]
fixing X for GeodeLX

[ 20080108002540 ]
kvm nfs hang

[ 20080107160836 ]
screen -c relative path bug

[ 20080105132854 ]
WeeChat spell suggestions

[ 20071219221358 ]
show current git branch in zsh

[ 20071217141037 ]
wmiirc-lua kitchen sink repository

[ 20071212100316 ]
protecting sshd from OOM killer

[ 20071204234232 ]
wmiirc-lua v0.2.1 remembers a bit more

[ 20071013205336 ]
wmiirc-lua v0.2 has suspend and raw modes

[ 20070929112345 ]
wmiirc-lua debianization

[ 20070924104140 ]
zsh tip of the day - global aliases

[ 20070915094213 ]
wmiirc-lua v0.1.1

[ 20070913130838 ]
comparing two directories

[ 20070909204125 ]
git-rebase --interactive

[ 20070908115905 ]
zsh tab completion awesomeness

[ 20070902000736 ]
wmiirc in lua

[ 20070831150306 ]
debugging with -dbg libraries

[ 20070831142646 ]
svn status like output in git

[ 20070829141847 ]
Git Cheat Sheet

[ 20070821142038 ]
switching to abiword

[ 20070811105746 ]
forwarding ssh and X through screen

[ 20070807112531 ]
git-svnup

[ 20070724082355 ]
reducing power consumption

[ 20070722123734 ]
Makefile template

[ 20070722002649 ]
less, colourful

[ 20070719162359 ]
irssi docs

[ 20070716114553 ]
qemu eats up /dev/shm

[ 20070710214512 ]
git-clean in svn land

[ 20070705113139 ]
ipw2200 not working

[ 20070627191916 ]
git slides updated

[ 20070618220649 ]
unpopular debian packages on my system

[ 20070611125852 ]
git-svn with multiple branches

[ 20070517085321 ]
Linus on Git at Google

[ 20070510134551 ]
vim modelines insecure

[ 20070504205042 ]
bios disassembler

[ 20070504124124 ]
dd hex arguments

[ 20070503013555 ]
urxvt mouseless url yanking

[ 20070502211941 ]
gitdiff.vba v2

[ 20070419234350 ]
india

[ 20070418155857 ]
zsh fun

[ 20070418143632 ]
pipe to pastey.net

[ 20070418094151 ]
vimgrep alias

[ 20070416202545 ]
mouse-free

[ 20070406141850 ]
ATA messages via SCSI layer

[ 20070330221019 ]
GITDiff vim plugin

[ 20070329011735 ]
git presentation for OCLUG

[ 20070328123631 ]
fixing vim's [[ and ]] for bad code

[ 20070316092236 ]
pxeboot and nfsroot with debian

[ 20070312134706 ]
etc snapshots with git

[ 20070307004041 ]
remote power switch

[ 20070222215355 ]
klips-less openswan git tree

[ 20070221041316 ]
git caching for v1.5.x

[ 20070218002214 ]
klips loses zlib

[ 20070209172606 ]
vim and linux CodingStyle

[ 20070207205427 ]
my kqemu install

[ 20070204100100 ]
leaner meaner openswan

[ 20070115111917 ]
wmii+ruby xlock action

[ 20070112131252 ]
cloning xterms in wmii+ruby

[ 20070102010551 ]
wmii+ruby talk for OCLUG

[ 20061228220641 ]
dump and restore

[ 20061218100219 ]
C style

[ 20061101002027 ]
fetching all git branches from remote

[ 20061028111607 ]
local caching for git repos

[ 20061020145437 ]
automatic version creation with git

[ 20061018213306 ]
wmii w/ ruby wmiirc

[ 20061018201907 ]
small fonts

[ 20061007151802 ]
google-codesearch from vim

[ 20060928020813 ]
shell commands

[ 20060920093957 ]
letting screen apps use the ssh-agent

[ 20060908223613 ]
mpdscribble stream support

[ 20060907125149 ]
glGo on ubuntu/dapper amd64

[ 20060906163240 ]
lbdb and mutt

[ 20060902145643 ]
vim tutorial

[ 20060902135722 ]
fixing your terminal

[ 20060828124713 ]
apt-get pdiffs

[ 20060824224842 ]
256 colour xterms

[ 20060824152658 ]
dynamic IPcomp

[ 20060824145428 ]
inkscape++

[ 20060818150516 ]
tags/cscope for system headers

[ 20060805131557 ]
opteron 170, part 4

[ 20060805101941 ]
opteron 170, part 3

[ 20060803233234 ]
opteron 170, part 2

[ 20060802210126 ]
opteron 170

[ 20060729144129 ]
OLS keysigning / 2006

[ 20060728105500 ]
git-find findings

[ 20060727162941 ]
starting on git-find

[ 20060727113632 ]
git-graft and git-find brainstorm

[ 20060726224531 ]
pretty function tracing

[ 20060713174723 ]
uml and multiple network segments

[ 20060707182236 ]
lastfm artist and title to clipboard

[ 20060706162256 ]
reverting a git changeset

[ 20060629212003 ]
user #3

[ 20060628083456 ]
firefox crashes with form input

[ 20060621151402 ]
git vs hg

[ 20060612222204 ]
ldap account management

[ 20060612194523 ]
stupid ldap

[ 20060608092157 ]
rpm hell is right

[ 20060605095726 ]
OpenSSH VPNs

[ 20060604114317 ]
Lenovo lost a customer

[ 20060601234010 ]
generating html colourized sourcecode

[ 20060601211716 ]
ion3 greatness and acting on X selections

[ 20060526085644 ]
software RAID10 performance

[ 20060525234148 ]
learning to love git

[ 20060524121638 ]
recent vim7 articles

[ 20060516095748 ]
bootstrapping debian on my sbc

[ 20060428145140 ]
entropy injection

[ 20060423140628 ]
Adam

[ 20060414202507 ]
converting mp3s to CD

[ 20060413232836 ]
secure apt-get

[ 20060412194423 ]
xen domain0 on debian

[ 20060410220525 ]
LVM2 on RAID1 mirror

[ 20060410102824 ]
building a RHEL4 kernel w/ kdb support

[ 20060407230939 ]
xen on debian

[ 20060407230818 ]
Upgraded look

[ 20060330131334 ]
Flattered by a copy

[ 20060328165153 ]
vim7 from source

[ 20060308123539 ]
Perl, Catalyst, CPAN, and Debian

[ 20060308123302 ]
last.fm

[ 20060128124841 ]
carcassonne and zombies

[ 20060120135931 ]
Election Humour

[ 20050925130002 ]
ldap on debian

[ 20050528190034 ]
Error while mapping shared library sections

[ 20050124130158 ]
IRC over email gateway

[ 20050110225522 ]
brute force attacks sshd?

[ 20050108095026 ]
LDAP authentication (part 1)

[ 20041124130146 ]
sawfish workspace themes

[ 20041113082651 ]
Mini-DV to divx using mencoder

[ 20041004084525 ]
notes on vserver

[ 20040922104334 ]
fast kernel logging

[ 20040803104122 ]
Digital Rebel for sale... GONE

[ 20040714202912 ]
OpenOffice resources

[ 20040603175746 ]
photo editing

[ 20040601082817 ]
WRT54G

[ 20040503205227 ]
Digital Rebel

[ 20040420200136 ]
Open Office templates

[ 20040326082602 ]
bash vi editing mode

[ 20040315204142 ]
debian install CDs

[ 20040312155542 ]
change of jobs

[ 20040308091554 ]
spamassasin extras

[ 20040305163216 ]
cool debian tools

[ 20040305155708 ]
first post!





Bart Trojanowski
http://www.jukie.net/~bart
bart@jukie.net