[U-Boot] PCI configuration Issue for QEMU ACPI Support

[Saket Sinha]

Hi,

This is regarding the PCI configuration Issue for QEMU ACPI Support.

I am comparing  arch/x86/cpu/qemu/acpi/pci-crs.asl and
arch/x86/dts/qemu-x86_q35.dts and we find there are different ranges
been specified for PCI configuration in both the files.

As per my understanding for Qemu q35 (emulation of the ICH9 host
chipset) where we have PCIe support which is made possible by PCI
express enhanced accessmechanism (ECAM).
This address is 0xe0000000 which is what I have put in
arch/x86/dts/qemu-x86_q35.dts when I am memory mapping the PCI bus.

I do not find this range in listed in arch/x86/dts/qemu-x86_q35.dts
where  0x80000000 which is the start of the range in the device tree.

Thus U-Boot sets PCI to map into memory starting at 0x80000000 but
when Linux starts booting with ACPI support it gets different values
and we get PCI configuration errors in the Linux boot bootup logs.


Regards,
Saket Sinha