Hi Laszlo,

OK, I see, let's me try. And I have another question:

Where should the low-level library be placed? Under the 
UefiCpuPkg/Library and as the same folder as CpuMmuLib?


Thanks,
Chao
On 2024/3/5 17:26, Laszlo Ersek wrote:
> Hello Chao,
>
> On 3/4/24 04:39, Chao Li wrote:
>> Hi Laszlo,
>>
>> OK.
>>
>> When I discussed the CpuMmuLib API as a public API with Ray in the early
>> days, the API recommended by Ray should be the patch 13 in this series,
>> which only contains set/get memory region attribute, but in the first
>> version in this series, it contains more API, one is ConfigureMmu API,
>> which is included in ARM and RISCV versions. This API provides a
>> interface called in PEI or DXE stage, it will configures the MMU and
>> enables it, such as creating the page tables, filling the static page
>> tables, cofniguring the MMU registers, enbale MMU, etc.
>>
>> The paths for ARM and RISCV version APIs:
>>
>> ARM: ArmPkg/Include/Library/ArmMmuLib.h
>>
>> RISCV: UefiCpuPkg/Include/Library/BaseRiscVMmuLib.h
> I have now re-read this subthread in its entirey, and I think I
> understand what's up.
>
> What confused me recently was your expression "so should we open
> configure API?"
>
> I think what you meant by "opening" was "publicly declaring".
>
> Anyway, here's my recommendation (consistently with what I said earlier
> in this thread):
>
> - I think you need a new (lower-level) library class and instance for
> exposing ConfigureMemoryManagementUnit().
>
> Please see:<https://edk2.groups.io/g/devel/message/114972>  (msgid
> <2a91f2f0-df4c-e106-65cd-79be167224f2@redhat.com>).
>
> - I do not recommend trying to unify the new LoongArch library classes
> (low level and high level) with "ArmMmuLib.h" or "BaseRiscVMmuLib.h".
>
> Each of "ArmMmuLib.h" and "BaseRiscVMmuLib.h" seems to declare both
> low-level and high-level interfaces. For LoongArch, we apparently don't
> want that; hence the idea to introduce two library classes for LoongArch
> -- that may be considered an improved design.
>
> At the same time, I don't believe that this requires us to unify
> "ArmMmuLib.h" and "BaseRiscVMmuLib.h" with the new, LoongArch-motivated
> library class design.
>
> Laszlo


-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#116377): https://edk2.groups.io/g/devel/message/116377
Mute This Topic: https://groups.io/mt/103971653/7686176
Group Owner: devel+owner@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io]
-=-=-=-=-=-=-=-=-=-=-=-