FYI:
IOMMU=pt means pass-through, as in no DMA protection.
AMD_IOMMU is for the bulldozer and piledriver based systems, v2 is for
the newer excavator and beyond stuff that has vAPIC
On 05/16/2017 10:33 AM, Corbin Bird wrote:
On 05/15/2017 09:59 PM, taii...@gmx.com wrote:
On 05/15/2017 12:58 AM, Ian Zimmerman wrote:
The 990FX / 790FX Chipset doesn't have a GART / AGP Aperature or IOMMU
in it. The CPU contains the original K8 IOMMU ( v1 ) engineered /
converted from a GART.
The 8 and 9 series (not 7) does have an IOMMU, AMD-Vi v1.26.
I have two 890 series (but the server flavor - SR5690 chipset) boards
with an IOMMU and it works great, I play games in a VM with an attached
graphics card on my libre firmware KGPE-D16 and devices are DMA restricted.
Most consumer boards don't properly implement this feature, in fact I
have never seen one that did which is why I bought my coreboot (libre
init variant) D16.
It wouldn't be that difficult to port coreboot to your board if you want
this to work FYI.
Thank you for that info.
Corrections based on fact are appreciated.
http://support.amd.com/TechDocs/43869.pdf
Hell yeah dude, this documentation backs up the fact that the IOMMU is
on the northbridge - not the CPU.
---
How does one 'port' coreboot?
Last time I went to the coreboot site, I didn't see anything really
helpful to me.
The documentation really sucks, its DIY or die - but I have never
programmed anything before in my life and I figured out how to port boards.
Doesn't the 'CPU voltage table firmware blob' require signing NDA's?
Naah you don't need that on most *good* systems, and
bulldozer/piledriver era AMD was cool with releasing documentation.
Corbin
https://www.coreboot.org/Developer_Manual
https://www.coreboot.org/Motherboard_Porting_Guide
You would start with the KCMA-D8, as it is the closest board - then
change the superio, irq mappings, acpi etc. It takes some figuring out
for yourself as there isn't really a detailed guide for it.
