Can't get to installer "pmap_steal_memory"

[SAMEH209]

I'm trying to install Yosemite on my HP XW6600 Workstation.
Specs:
CPU: Dual Intel Xeon E5410 @ 2.3GHz

RAM: 16GB
GPU: GTX 950 1GB

When trying to get to the installer I got a kernel panic saying "Unable to find driver for this platform: \"ACPI"\"

but I managed to bypass that by booting with "-f -v -x acpi=off" and now I get another KP saying "pmap_steal_memory" and I have no idea what's the cause of this.