Messages in this thread | | | From | Jon Masters <> | Date | Wed, 19 Apr 2017 01:00:15 -0400 | Subject | Re: Doubt on first access for PCIe device |
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On 04/11/2017 10:15 AM, abhijit wrote:
> Here I am assuming, the completer ID will be device number and function > number that will eventually programmed in to device. In that case, my > question is, without first write, how read request(VENDOR ID read) is > serviced/routed?
You'll want to read about PCIe enumeration at boot time and how the BIOS walks the topology to assign these (which an OS may later re-number). In particular, read about ECAM for configuration. This uses memory mapped config space read/write accessors that target a memory address space under the control of the root complex.
Jon.
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