AHCI Command List should be in Physical address or MMIO?

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shore
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Joined: Wed Sep 04, 2019 9:00 pm

AHCI Command List should be in Physical address or MMIO?

Post by shore »

Hi I'm trying to write an AHCI driver following https://wiki.osdev.org/AHCI.

In the sample program, start from "port->clb", which is the pointer to "Command List" and all following pointers, are defined by OS programmer.

Since ABAR and Ports are memory mapped address, I would like to ask if the following structure should be located in physical memory (RAM) or the memory mapped address??

Thanks a lot!
Octocontrabass
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Re: AHCI Command List should be in Physical address or MMIO

Post by Octocontrabass »

I thought this diagram made it pretty clear.

Image
shore
Posts: 15
Joined: Wed Sep 04, 2019 9:00 pm

Re: AHCI Command List should be in Physical address or MMIO

Post by shore »

Octocontrabass wrote:I thought this diagram made it pretty clear.

Image
So it would be the RAM/physical memory right? and the AHCI controller would read from DMA method.

Thanks a lot
Octocontrabass
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Re: AHCI Command List should be in Physical address or MMIO

Post by Octocontrabass »

Yes, that's correct.
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