Alpine 1A420

Alpine 1A420 is a firmware of an iPhone prototype discussed in a MacRumors thread. It is the earliest known build of iOS, and was compiled on 2007.

Based on, this release is called Alpine build 1A420. The main user interface of this firmware is SkankPhone.app which features a built-in Operator screen, used to test the various buttons and sensors. Interestingly, this version of Operator plays portions from INXS songs when testing the speakers, whilst newer versions play various Chinese songs.

Restore
Instead of it being done through a ramdisk, the restore tools seem all to be right there in the OS. This is probably because they originally did restores through userland.

Baseband

 * The iPhone Prototype came with 03.06.01_G
 * The firmware dump comes (in ) with 03.06.00

Flashing 03.06.00 on a retail iPhone can be done with bbupdater, but results in a loss of Carrier Network connectivity.

Kernel Caches
In, there are kernels for other CPUs, such as S5I3000, S5L8900XFPGA and Freescale MX31. Apple was evaluating various ARM platforms at the time, ultimately settling on the S5L8900 series. Engineers who worked on early iPhone prototypes have confirmed that a Freescale MX31 prototype did exist as the first ARM hardware iPhone OS ran on, after being tested on PowerMac G3-based prototypes.

This firmware has the kernel version.