Information about CXL

Information about CXL

[Ananth, Rajesh]

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Hi,

We are in the process of developing OpenBMC based firmware update mechanism for the PCI-e based CXL controllers. The CXL controllers typically expose their interfaces as a memory mapped mailbox in the PCI-e space.

Basic things we are looking forward to implement are (depends on the feasibility here):

1.       Probe the PCI-e config space to locate our controller  (using PCI VID/DID)

2.       Probe the PCI-e config space to access the memory mapped registers

3.       Use the mapped registers to send commands and update the firmware

We would like to have some pointers on how to proceed (sample code/development docs etc.,). We are initially targeting s2600wf board as our target.

Thanks,
Rajesh



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Re: Information about CXL

[Patrick Williams]

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From what I've seen, the BMC would interact with a CXL using MCTP and not PCIe. See https://www.dmtf.org/sites/default/files/standards/documents/DSP0281_1.0.0_0.pdf
---
Patrick Williams

> On May 9, 2024, at 4:58 PM, Ananth, Rajesh <rajesh.ananth@smartm.com> wrote:
> 
> 
> Hi,
>  
> We are in the process of developing OpenBMC based firmware update mechanism for the PCI-e based CXL controllers. The CXL controllers typically expose their interfaces as a memory mapped mailbox in the PCI-e space.
>  
> Basic things we are looking forward to implement are (depends on the feasibility here):
> 1.       Probe the PCI-e config space to locate our controller  (using PCI VID/DID)
> 2.       Probe the PCI-e config space to access the memory mapped registers
> 3.       Use the mapped registers to send commands and update the firmware
>  
> We would like to have some pointers on how to proceed (sample code/development docs etc.,). We are initially targeting s2600wf board as our target.
>  
> Thanks,
> Rajesh
>  
>  

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