Developing for a jailbroken iPhone, A to Z (iPhone 3.0)

UPDATE: NEWGUIDE NEWGUIDE NEWGUIDE!

Vital iPhone stats for this post:
iPhone version: 3G (should work with 2G and 3GS)
iPhone OS version: 3.0 (rock the hizzouse!)
Jailbreak status: Jailbroken using Pwnage Tool.

The Goal: Get live on-device XCode debugging without being a paying ADC member. This time OS 3.0 style.

Abstract: Same deal as last round. We want to break code signing on the iPhone, and then we want to make Xcode load software into it automatically to debug. In SDK 2.2 (Xcode version 3.1.2) this was just a simple matter of editing some Plists and such to tell Xcode to ignore provisioning profiles. SDK 3.0 (Xcode version 3.1.3) broke these Plist editing tricks. For a while, all you could do was try to hack SDK 3.0 support into Xcode 3.1.2, installed with SDK 2.2. That was really very hairy, though, if you didn’t want to have to switch environments to debug (close and restart Xcode). It was also annoying to configure. Luckily, there’s a new, much less ghetto way. It’s all based on a little hack posted by <zim> in this thread (coral). Essentially, it just replaces a few bits in the Xcode plugin that actually handles the device build, which restores our build and go ability.

Procedure: things marked (2.2 STEP) will already be done if you followed my previous procedure, and you may not need to repeat them.

1. Jailbreak your phone. In Cydia, add the source http://iphone.org.hk/apt/. Install the package “Installd Patch” (this used to be Mobileinstallation Patch, just a name change in OS 3.0). Thanks go to @javacom for this lovely little hack, and lots of other wonderful info on his blog. Seriously, if you’re reading this right now, you should be following him. UPDATE 8/3/09: Some are reporting that if you’re on OS 3.0.1 or possibly a 3GS (or both) Installd Patch may or may not actually install. If this is the case, or if you get weird message about your identity being no longer valid, try installing AppSync as a stand-in.
2. (2.2 STEP) You will need a signing identity. We’ll break the check such that it doesn’t have to be an official ADC one, so you can make your own using this guide from apple (coral). What you are doing in this step is creating a “Self-Signing Identity.” Note that you should name the identity “iPhone Developer” EXACTLY to avoid having to change a bunch of the steps below.
3. (2.2 STEP) Open your project and go to (menu) Project > Edit Project Settings. In the list of properties, find “Code Signing Identity” > “Any iPhone OS Device” and click in the empty box. Assuming there are no entries in the menu, click “Other” and type in the same name you used to generate the code signing certificate above in step (2). For example: in step 2, I used the name “iPhone Developer” and that is exactly what I put in this field. Hit OK and close that settings window. This setting should persist in future projects, and you shouldn’t have to do this again.

Add the special 3.0 sauce:

1. Open a terminal.
2. type cd ~/Desktop (enter)
3. type vi script (enter)
4. tap i on your keyboard (to enter “insert” mode in vi).
5. Copy/Paste (cmd-v) the following code into your terminal window:
#!/bin/bash
cd /Developer/Platforms/iPhoneOS.platform/Developer/Library/Xcode/Plug-ins/iPhoneOS\ Build\ System\ Support.xcplugin/Contents/MacOS/
dd if=iPhoneOS\ Build\ System\ Support of=working bs=500 count=255
printf "\x8f\x2a\x00\x00" >> working
dd if=iPhoneOS\ Build\ System\ Support of=working bs=1 skip=127504 seek=127504
/bin/mv -n iPhoneOS\ Build\ System\ Support iPhoneOS\ Build\ System\ Support.original
/bin/mv working iPhoneOS\ Build\ System\ Support
chmod a+x iPhoneOS\ Build\ System\ Support
6. type ESC, then : x (colon,x) (enter). This saves and exits in vi.
7. type chmod 777 script (enter)
8. type ./script (enter) This will execute the script to patch the Xcode plugin. Assuming it completes correctly, you should be good to go, try it out!

If it executed correctly, you should see something like this:

alex-whittemores-computer:Desktop alex$ ./script
255+0 records in
255+0 records out
127500 bytes transferred in 0.035658 secs (3575647 bytes/sec)
191056+0 records in
191056+0 records out
191056 bytes transferred in 1.782819 secs (107165 bytes/sec)

And the final step (added 7/18/09, fixes the issue where debugging failed on 3.0 and where the binary would fail to launch on 2.2.1): Codesign the binary before it hits the phone (this got patched out in the new Xcode method above). In terminal:

1. mkdir /Developer/iphoneentitlements30
2. cd /Developer/iphoneentitlements30
3. curl -O http://www.alexwhittemore.com/iphone/gen_entitlements.txt
4. mv gen_entitlements.txt gen_entitlements.py
5. chmod 777 gen_entitlements.py

Add the build phase: in Xcode, select the menu options “Project > New Build Phase > New Run Script Build Phase”, and enter the following script:

export CODESIGN_ALLOCATE=/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/codesign_allocate
if [ "${PLATFORM_NAME}" == "iphoneos" ]; then
    /Developer/iphoneentitlements30/gen_entitlements.py "my.company.${PROJECT_NAME}" "${BUILT_PRODUCTS_DIR}/${WRAPPER_NAME}/${PROJECT_NAME}.xcent";
    codesign -f -s "iPhone developer" --resource-rules "${BUILT_PRODUCTS_DIR}/${WRAPPER_NAME}/ResourceRules.plist" \
         --entitlements "${BUILT_PRODUCTS_DIR}/${WRAPPER_NAME}/${PROJECT_NAME}.xcent"  "${BUILT_PRODUCTS_DIR}/${WRAPPER_NAME}/"
fi

NOTE: You will have to repeat this step for every project! (That is, the add build phase part, not the terminal part.) It’s a bummer, but I’m not sure there’s any way around it. I’ll try to figure out if you can persist custom build phases across projects.

Note: You may notice that a number of the steps you remembered from last time are gone now. I believe the few-byte hack above takes care of all the steps. As far as I know, there’s no need to even modify your projects with that one Plist key, everything just works. I currently have this setup working on my production machine, but just to be sure, I’m going to boot up my external disk and I’m going to test this procedure start to finish. As usual, don’t hesitate to comment if you have questions or run into trouble, and I’ll do my best to help.

Special thanks regarding the last step to zim at iPhone Dev SDK forums and to Sylvain Munaut, whose script gen_entitlements.py is used above.