Re: [edk2-devel] [Patch v3 2/3] NetworkPkg: Add DSC/FDF include segment files to NetworkPkg.

["Andrew Fish" <afish@apple.com>]

> On May 6, 2019, at 11:23 AM, Laszlo Ersek <lersek@redhat.com> wrote:
> 
> On 05/05/19 17:21, Liming Gao wrote:
>> Reply for the comments in the patch content. 
>>> -----Original Message-----
>>> From: Laszlo Ersek [mailto:lersek@redhat.com]
>>> Sent: Monday, April 29, 2019 9:05 PM
>>> To: devel@edk2.groups.io; Gao, Liming <liming.gao@intel.com>
>>> Cc: Wu, Jiaxin <jiaxin.wu@intel.com>; Ye, Ting <ting.ye@intel.com>; Fu, Siyuan <siyuan.fu@intel.com>
>>> Subject: Re: [edk2-devel] [Patch v3 2/3] NetworkPkg: Add DSC/FDF include segment files to NetworkPkg.
>>> 
>>> On 04/25/19 14:37, Liming Gao wrote:
> 
> [...]
> 
>>>> diff --git a/NetworkPkg/NetworkComponents.dsc.inc b/NetworkPkg/NetworkComponents.dsc.inc
>>>> new file mode 100644
>>>> index 0000000000..aede5ea8be
>>>> --- /dev/null
>>>> +++ b/NetworkPkg/NetworkComponents.dsc.inc
>>>> @@ -0,0 +1,61 @@
>>>> +## @file
>>>> +# Network DSC include file for [Components*] section of all Architectures.
>>>> +#
>>>> +# This file can be included to the [Components*] section(s) of a platform DSC file
>>>> +# by using "!include NetworkPkg/NetworkComponents.dsc.inc" to specify the INF files
>>>> +# of EDKII network drivers according to the value of flags described in
>>>> +# "NetworkDefines.dsc.inc".
>>>> +#
>>>> +# Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
>>>> +#
>>>> +#    SPDX-License-Identifier: BSD-2-Clause-Patent
>>>> +#
>>>> +##
>>>> +
>>>> +!if $(NETWORK_ENABLE) == TRUE
>>>> +  MdeModulePkg/Universal/Network/DpcDxe/DpcDxe.inf
>>>> +
>>>> +  !if $(NETWORK_SNP_ENABLE) == TRUE
>>>> +    MdeModulePkg/Universal/Network/SnpDxe/SnpDxe.inf
>>>> +  !endif
>>>> +
>>>> +  !if $(NETWORK_VLAN_ENABLE) == TRUE
>>>> +    MdeModulePkg/Universal/Network/VlanConfigDxe/VlanConfigDxe.inf
>>>> +  !endif
>>>> +
>>>> +  MdeModulePkg/Universal/Network/MnpDxe/MnpDxe.inf
>>>> +
>>>> +  !if $(NETWORK_IP4_ENABLE) == TRUE
>>>> +    MdeModulePkg/Universal/Network/ArpDxe/ArpDxe.inf
>>>> +    MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Dxe.inf
>>>> +    MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Dxe.inf
>>>> +    MdeModulePkg/Universal/Network/Udp4Dxe/Udp4Dxe.inf
>>>> +    MdeModulePkg/Universal/Network/Mtftp4Dxe/Mtftp4Dxe.inf
>>>> +  !endif
>>>> +
>>>> +  !if $(NETWORK_IP6_ENABLE) == TRUE
>>>> +    NetworkPkg/Dhcp6Dxe/Dhcp6Dxe.inf
>>>> +    NetworkPkg/Ip6Dxe/Ip6Dxe.inf
>>>> +    NetworkPkg/Udp6Dxe/Udp6Dxe.inf
>>>> +    NetworkPkg/Mtftp6Dxe/Mtftp6Dxe.inf
>>>> +  !endif
>>>> +
>>>> +  NetworkPkg/TcpDxe/TcpDxe.inf
>>>> +  NetworkPkg/UefiPxeBcDxe/UefiPxeBcDxe.inf
>>>> +
>>>> +  !if $(NETWORK_TLS_ENABLE) == TRUE
>>>> +    NetworkPkg/TlsDxe/TlsDxe.inf
>>>> +    NetworkPkg/TlsAuthConfigDxe/TlsAuthConfigDxe.inf
>>>> +  !endif
>>>> +
>>>> +  !if $(NETWORK_HTTP_BOOT_ENABLE) == TRUE
>>>> +    NetworkPkg/DnsDxe/DnsDxe.inf
>>>> +    NetworkPkg/HttpDxe/HttpDxe.inf
>>>> +    NetworkPkg/HttpUtilitiesDxe/HttpUtilitiesDxe.inf
>>>> +    NetworkPkg/HttpBootDxe/HttpBootDxe.inf
>>>> +  !endif
>>>> +
>>>> +  !if $(NETWORK_ISCSI_ENABLE) == TRUE
>>>> +    NetworkPkg/IScsiDxe/IScsiDxe.inf
>>>> +  !endif
>>>> +!endif
>>> 
>>> OK, this matches the FDF include file (except for IScsiDxe, but that's a
>>> problem I pointed out under (6)).
>>> 
>>> The NETWORK_TLS_ENABLE part looks good too. It's worth noting that it
>>> won't be suitable for OVMF, because OVMF hooks TlsAuthConfigLib into
>>> TlsAuthConfigDxe, for dynamically setting the variables
>>> "HttpTlsCipherList" and "TlsCaCertificate".
>>> 
>>> But, that's not a problem for this generic DSC include file. OVMF can
>>> simply set NETWORK_TLS_ENABLE to FALSE, and preserve its own (current)
>>> TLS_ENABLE build flag, and everything in the DSC/FDF that depends on
>>> that platform build flag.
>> 
>> After include NetworkPkg/NetworkComponents.dsc.inc, you can override TlsAuthConfigDxe.inf
>> with the below to match Ovmf usage. 
>>  NetworkPkg/TlsAuthConfigDxe/TlsAuthConfigDxe.inf {
>>    <LibraryClasses>
>>      NULL|OvmfPkg/Library/TlsAuthConfigLib/TlsAuthConfigLib.inf
>>  }
> 
> Oh, that's very interesting. Is this a documented feature of the DSC
> files (from the DSC spec), or just something that happens to work with
> BaseTools?
> 
> In other words, are DSC files officially permitted to reference the same
> component INF file multiple times, and the last reference will take
> effect (including PCD and lib overrides)?
> 

Laszlo,

Seems like this behavior would be good to define if it is not documented. I would expect an error (multiple definition), or a warning (last one winning). 

For best compatibility promoting the current behavior, assuming it makes sense, is probably the way to go.

Thanks,

Andrew Fish


> 
> (And thank you for the rest of the answers as well.)
> 
> Cheers,
> Laszlo
> 
> 
>