Mac Pro 1,1 to 2,1 Firmware Upgrade

[Guest christiann]

Will I need to upgrade the CPU to do this, or can I stick with the current one in the Mac Pro 1,1 and upgrade straight to 2,2? It’s the 2006 model, Want to flash the firmware so it can run El Capitan.

 

Thanks, Christian

 

Source: MacRumors