[iOS] tweak project development

在jailed break的手機當中, 我們如果想要取代掉/新增一些原本apple提供的功能, 我們就必須要寫tweak(我自己理解就是寫hook, 然後讓系>統會自動呼叫到你寫的callback function).

要達到這件事情, 除了之前教的先安裝theos之外, 我們還必須使用ios private framework (也就是apple沒公開的SDK), 這邊有兩種方式

1. generate header from class-dump or class-dump-z tool
   

   $ class-dump -H /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk/System/Library/PrivateFrameworks/SpringBoardServices.framework/SpringBoardServices
   $ ls
   BKSAccelerometerDelegate-Protocol.h              SBSCardItem.h
   CDStructures.h                                   SBSCardItemsController.h
   NSCoding-Protocol.h                              SBSCardItemsControllerRemoteInterface-Protocol.h
   NSCopying-Protocol.h                             SBSCompassAssertion.h
   NSObject-Protocol.h                              SBSLocalNotificationClient.h
   SBAppLaunchUtilities.h                           SBSPushStore.h
   SBCardItemsControllerRemoteInterface-Protocol.h  SBSRemoteNotificationClient.h
   SBLaunchAppListener.h                            XPCProxyTarget-Protocol.h
   SBSAccelerometer.h
   

2. copy others from internet
   (1) https://github.com/nst/iOS-Runtime-Headers/tree/master/PrivateFrameworks
   (2) https://github.com/rpetrich/iphoneheaders
       這是我用的, 使用這個你必須要做一些額外的工作
       

$ find /Applications/Xcode.app/ -name IOSurfaceAPI.h
$ cp /Applications/Xcode.app//Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk/System/Library/Frameworks/IOSurface.framework/Versions/A/Headers/IOSurfaceAPI.h $THEOS/include/IOSurface/

Comment out the following line in this file (IOSurfaceAPI.h):

/* This call lets you get an xpc_object_t that holds a reference to the IOSurface.                                           
   Note: Any live XPC objects created from an IOSurfaceRef implicity increase the IOSurface's global use
   count by one until the object is destroyed. */
//xpc_object_t IOSurfaceCreateXPCObject(IOSurfaceRef aSurface)
//  IOSFC_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_NA);
                              
/* This call lets you take an xpc_object_t created via IOSurfaceCreatePort() and recreate an IOSurfaceRef from it. */
//IOSurfaceRef IOSurfaceLookupFromXPCObject(xpc_object_t xobj)
//  IOSFC_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_NA);

我自己是使用別人產生的header, 把這些header copy到$THEOS/include 下面, 接下來就可以進行tweak project了

$ /opt/theos/bin/nic.pl 
NIC 2.0 - New Instance Creator
------------------------------
  [1.] iphone/application
  [2.] iphone/library
  [3.] iphone/preference_bundle
  [4.] iphone/tool
  [5.] iphone/tweak
Choose a Template (required): 5
Project Name (required): ooooo
Package Name [com.yourcompany.ooooo]: 
Author/Maintainer Name [ytshen]:       
[iphone/tweak] MobileSubstrate Bundle filter [com.apple.springboard]: 
Instantiating iphone/tweak in ooooo/...
Done.
$ ls ooooo/
Makefile    Tweak.xm    control     ooooo.plist theos

接下來你就可以進行tweak的實作, 這邊我在xcode 4.5 + mac os 10.8 lion下面會遇到一些問題, 像是找不到arm6 symbol, 這是因為後來只支援arm7.

要修改Makefile

export ARCHS=armv7
export TARGET=iphone:latest:4.3
SDKVERSION=6.0
 
include theos/makefiles/common.mk
   
TWEAK_NAME = ooooo
ooooo_FILES = Tweak.xm
   
include $(THEOS_MAKE_PATH)/tweak.mk

並且要設定environment $SYSROOT 到你sdk的目錄.

$ echo $SYSROOT 
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk/

這邊使用一個很簡單的例子, 我們要改spring board一開始秀出一個alert (spring board就是iOS的桌面程式), 修改Tweak.xm:

#import 
 
%hook SpringBoard
 
-(void)applicationDidFinishLaunching:(id)application {
    %orig; // call the original method
    
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Welcome" 
        message:@"Welcome to your iPhone Brandon!" 
        delegate:nil 
        cancelButtonTitle:@"Thanks" 
        otherButtonTitles:nil];
    [alert show];
    [alert release];
}
%end

接下來就按照之前介紹的theos, make, make package, make package install. 就可以把這個tweak安裝在iPhone上面!

Reference

http://brandontreb.com/beginning-jailbroken-ios-development-your-first-tweak/
http://www.andyibanez.com/2012/07/02/create-a-mobilesubstrate-tweaks/
class-dump:
http://stevenygard.com/projects/class-dump/