If PCD is related to one structure in DEC/DSC, it can be refer as structure pointer in C source code. Here is wiki for its usage: https://github.com/lgao4/edk2/wiki/StrucutrePcd-Usage
Thanks Liming >-----Original Message----- >From: edk2-devel [mailto:[email protected]] On Behalf Of >Andrew Fish via edk2-devel >Sent: Tuesday, December 11, 2018 7:39 AM >To: Leif Lindholm <[email protected]> >Cc: [email protected] >Subject: Re: [edk2] [PATCH edk2-platforms] Platform/AMD/OverdriveBoard: >fix byte order of default MAC addresses > > > >> On Dec 10, 2018, at 3:33 PM, Leif Lindholm <[email protected]> wrote: >> >> On Mon, Dec 10, 2018 at 11:51:43PM +0100, Ard Biesheuvel wrote: >>> On Mon, 10 Dec 2018 at 23:14, Leif Lindholm <[email protected]> >wrote: >>>> >>>> On Wed, Dec 05, 2018 at 09:10:48PM +0100, Ard Biesheuvel wrote: >>>>> The PCDs containing the default MAC addresses are of type UINT64, >>>>> and so the byte order needs to be inverted. As they are currently, >>>>> both default MAC addresses are invalid since they have the multicast >>>>> bit set. >>>> >>>> Ah, oops. >>>> That would also prevent them from being "locally administered" and >>>> hence permissible without registering an entry in the OUI. >>>> >>>> However, to reduce someone interpreting the _new_ values that way >>>> instead, could you do one of: >>>> - Adding a comment explaining these are in reverse byte order. >>>> or >>>> - Convert them to the new Array type PCD[1], to make the bytes appear >>>> in natural order? >>>> >>>> [1] edk2 72a1d77694d51914c0dd6aa97dbfa58634b0a4a5 >>> >>> How does one refer to such a PCD from C code? >> >> Good question :) >> > >Seems like you would need cast the pointer to the data structure in the C >code. If I understand correctly the change in the PCD creation code is you can >now better structure the data, but it is no different on the consumer end and >you got a blob of bytes in both cases. > >Thanks, > >Andrew Fish > >> / >> Leif >> >>>>> Contributed-under: TianoCore Contribution Agreement 1.1 >>>>> Signed-off-by: Ard Biesheuvel <[email protected]> >>>>> --- >>>>> Platform/AMD/OverdriveBoard/OverdriveBoard.dsc | 4 ++-- >>>>> 1 file changed, 2 insertions(+), 2 deletions(-) >>>>> >>>>> diff --git a/Platform/AMD/OverdriveBoard/OverdriveBoard.dsc >b/Platform/AMD/OverdriveBoard/OverdriveBoard.dsc >>>>> index 05433d4472e8..2843e51f93f7 100644 >>>>> --- a/Platform/AMD/OverdriveBoard/OverdriveBoard.dsc >>>>> +++ b/Platform/AMD/OverdriveBoard/OverdriveBoard.dsc >>>>> @@ -469,8 +469,8 @@ DEFINE DO_CAPSULE = FALSE >>>>> gAmdModulePkgTokenSpaceGuid.PcdPort1NetSpeed|1 >>>>> >>>>> [PcdsDynamicDefault.common] >>>>> - gAmdStyxTokenSpaceGuid.PcdEthMacA|0x02A1A2A3A4A5 >>>>> - gAmdStyxTokenSpaceGuid.PcdEthMacB|0x02B1B2B3B4B5 >>>>> + gAmdStyxTokenSpaceGuid.PcdEthMacA|0xA5A4A3A2A102 >>>>> + gAmdStyxTokenSpaceGuid.PcdEthMacB|0xB5B4B3B2B102 >>>>> >>>>> [PcdsPatchableInModule] >>>>> gAmdModulePkgTokenSpaceGuid.PcdXgbeUseMacFromIscp|TRUE >>>>> -- >>>>> 2.19.2 >>>>> >> _______________________________________________ >> edk2-devel mailing list >> [email protected] >> https://lists.01.org/mailman/listinfo/edk2-devel > >_______________________________________________ >edk2-devel mailing list >[email protected] >https://lists.01.org/mailman/listinfo/edk2-devel _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
