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Ranges returned by VideoPortGetAccessRanges

DoaJC_BloggerDoaJC_Blogger Member Posts: 11

I have a couple of questions about the use of VideoPortGetAccessRanges() in a video miniport.

  1. The method has an argument specifying the number of ranges to return so how will I know how many ranges I should request? I think it will be specified in the GPU reference manual. Here's a screenshot from the PDF for the GPU I'm trying to support. There are 6 rows in this table, so would I request 6 ranges?

  1. Once I know how many ranges I need and VideoPortGetAccessRanges() has returned them, how will I know which is which? For example, there might be one for the framebuffer and one for MMIO. Are they guaranteed to be returned in a certain order, or do I need to check the size of each range and infer what it is?

Comments

  • Tim_RobertsTim_Roberts Member - All Emails Posts: 13,282

    There is one address range per BAR in the PCI configuration space. From this page, it looks like the device has 3 BARs, but you should check the PCI config space documentation. They are delivered in BAR order.

    Tim Roberts, [email protected]
    Providenza & Boekelheide, Inc.

  • DoaJC_BloggerDoaJC_Blogger Member Posts: 11

    That makes sense. Thank you. I was able to start matching things in the reference manual with a PCI configuration table I found.


  • Tim_RobertsTim_Roberts Member - All Emails Posts: 13,282

    By the way, what on earth are you doing? Writing a graphics driver is an ENORMOUS task. This page is from Intel's documentation, and all of Intel's graphics chips already have Windows drivers.

    Tim Roberts, [email protected]
    Providenza & Boekelheide, Inc.

  • DoaJC_BloggerDoaJC_Blogger Member Posts: 11

    I'm writing a GPL graphics driver for Windows 7 and XP x64.

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