Previously I posted about how to find bootrom version on Windows, go to that link in case you might want to check it out. When there’s a how to for Windows surely same case for Mac. So here’s a pictorial walk through to determine your iPhone bootrom version on Mac!
Steps to find iPhone 3GS bootrom version on Mac:
- As usual locate your iPhone in DFU mode after it’s connected to your computer.
- On the Apple menu click About This Mac menu

- You will see More Info menu or such inside the About This Mac section, so hit it!

- On your Hardware Contents list – click on USB – it’s on the left side from your screen

- On the USB Device section, hit on Apple Mobile Device (DFU Mode)

- Use the details pane, locate the Serial Number Field and at the end you will see your bootrom version.The version should look like [iBoot-359.3]

If your iPhone 3GS bootrom version is iBoot-359.3, which means it’s the old bootrom. So the new bootrom version is iBoot-359.3.2
[Via]