In the main network settings screen under System Preferences:

• leave telephone number blank
• use ‘WAP@CINGULARGPRS.COM’ for Account Name
• use ‘CINGULAR1′ for Password

Then click the advanced button and setup:

• Vendor generic
• Model GPRS (GSM/3G)
• APN is ‘wap.cingular’
• CID set to 1

After that starting up a network session with my Captivate attached over USB yielded a pretty quick network connection! Now if only they could fix these GPS issues….

• Install Wireshark
• Follow the instructions in the readme to also install the ChmodBPF script
• Under Sharing area of the OS X settings app configure your system to use an ethernet connection and share it out to wifi clients
• Now configure your device to connect to the wifi network provided by your system, test to make sure it works
• Startup Wireshark and set it to capture traffic (wifi is en1 on MacBook Pro systems, what I normally use)

And that’s it, you should now get quite readable dumps of what applications are doing to communicate. Lots of interesting things you can learn digging into how folks structure their client/server interaction.

1. Follow the instructions to download and build Android from source. Follow the whole thing (I had to create a case-sensitive disk image and all), including the actual build step. Otherwise you won’t have the libraries necessary and agcc will error out when you try to run it.
2. Add the prebuilt/darwin-x86/toolchain/arm-eabi-4.2.1/bin subdirectory of where ever you built the source to your PATH, add it to your .bash_profile if you want.
3. Download the agcc wrapper script, put it somewhere in your path, and make it executable.

Now you should be ready to compile a program and download it to your phone. This was my test app:

#include <stdio.h>

int main( int argc, char **argv ) {
  printf("Hello from Droid Hacks!\n");
  return 0;
}

And you should be able to compile it with “agcc hello.c -o hello” and end up with a hello executable:

~ > agcc hello.c -o hello
~ > file hello
hello: ELF 32-bit LSB executable, ARM, version 1 (SYSV), dynamically linked (uses shared libs), not stripped
~ >

And you can move the file across to the phone and run it. You’ll have to make a directory to push it into. The sdcard is marked as noexec, so you can’t run stuff from there. And the data directory has more restrictive permissions. So you’ll have to su and create a directory on the data partition, and relax the perms on that directory:

~ > adb shell
$ su
# mkdir /data/droidtest
# chmod 777 /data/droidtest
# exit
$ exit
~ > adb push hello /data/droidtest
418 KB/s (6747 bytes in 0.015s)
~ > adb shell
$ cd /data/droidtest
$ ls -l
-rwxrwxrwx shell    shell        6747 2009-05-27 08:56 hello
$ ./hello
Hello from Droid Hacks!
$

And of course you can run the same thing from the terminal on your device as well: