Enable apps generated by xcode 4.2 to support older iOS devices (armv6)

These days I encountered a very strange problem. For apps developed based on xcode 4.2, the exported IPA installation package cannot be installed on iPod Touch 2. Touch2 firmware version 4.2.1 has been jailbroken. Neither iTunes nor 91 mobile assistant nor synchronous push. However, other IPA files can be successfully installed on touch2. The IPA package generated by xcode 4.2 can be installed successfully and run smoothly on iPhone 4, iPhone 3gs, and iPod Touch 4, regardless of the firmware version. The initial analysis result is that the app generated by xcode 4.2 does not support touch2. In the past few days, I found some friends who helped me test the IPA installation package and asked some friends who have iOS development experience. Finally, a friend reminded me of xcode.
In 4.2, project-> build settings-> ubuntures-> release settings are related. After modification, the problem is finally solved. Thank you!

Cause Analysis: xcode 4.2's ubuntures settings default only armv7, that is, the new iOS device, including iPhone 3gs, iPhone 4, iPhone 4S, iPad, ipad2 and so on, while iPhone, iPhone 3G, iPod Touch, and iPod Touch 2 belong to the armv6 architecture.

Solution: Set ubuntures to armv6 armv7, as shown in:

Before modification:

After modification:

In this way, the generated IPA installation package can support old iOS devices.

In addition, you need to delete the required device capabilitiess In the info settings so that it is correctly compatible with the old iOS devices only after being submitted to the appstore.