A long time ago, Lolof and I managed to get an
EFI update for MacMini1,1 to MacMini2,1.
Unfortunately no application has ever been made for this ...
But here is
a shell script to perform the Upgrade / Downgrade :
MacMini Firmware Upgrade Utility.zip How to use the script :- Open "Terminal.app"
- type cd, spacebar " ", drag and drop your /MacMini Firmware Upgrade Utility/ folder in this window and press enter
- type sh MacMiniFirmwareUpgradeUtility.sh

- Then you will have 3 choices : "1) Upgrade", "2) Downgrade" or "3) Quit"
- Read carefully and follow the instructions
After the Upgrade your screen will be messed up, perform a PRAM reset to get it back (just follow the instructions)


Before the Downgrade you MUST make sure your RAM is 2GB or less.
It worked on my MacMini but I won't be be responsible if anything goes wrong on yours ...What the script does1. Create a RAM Disk
2. Copy files from the previous folder on this disk
3. Download
original Apple .dmg files
4. Extract the relevant .fd and efi files
5. Patch them if necessary
6. Give the choice of : Upgrade, Downgrade or Quit
7. Launch the relevant script (with
sudo, password needed)
8. Give instructions to perform the flash
9. Unmount the RAM Disk
How we created the files :The idea was to do the same as
iMac2006>2007 and
MacPro2006>2007.
But unlike these models MacMini2007 firmware has NEVER been released by Apple.
We got several dumps of MacMini2,1 .fd file with rEFIt.
We got rid of the personal data by keeping only the common parts of the .fd
We modified the EFI updater to accept our file
CreditsLolof and
Alexcooltranquille for the dumps
Sebinouse and
Lolof for the modified files
Sebinouse for the Script
Special Thanks to
MacEFIRom for the original idea (and for his applications that helped me to create this script

)
Tiny Thanks to Shinso for
his tutorial making our work user friendly but he forgot to give us credits

... not cool !