Xcode4.2生成app支持旧版iOS设备

先说一下armv6 与 armv7的区别:

What is ARMv7?
It's a new CPU architecture of iPhone. Make some apps run faster.

What does ARMv7 to do with me?
Here is a post by most_Unique found on iPhoneCake.

Most apps today use FAT binary which cracked on ARMv7 device will not work on ARMv6 device.

• Armv7的机器有：iPhone4, iPhone4s, iPad, iPad2, iPhone 3GS, iPod 3G
• Armv6的机器有：iPhone 2G, iPhone3G, iPod 1G, iPod2G

那么要在老机器上跑, 比如iphone3G, 就必须支持armv6

Xcode 4.2的Architectures设置默认只有armv7

解决方法：将Architectures设置为armv6 armv7，如图：

修改前：

修改后：

这样设置后生成的ipa安装包就可以支持旧版iOS设备了。