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