> You can have different libs and different flags per driver. You use the
{} syntax on the INF file in the components section. This is already done
in the Shell.DSC to control PCDs separating the ShellLib when used for the
shell compared to ShellLib used for shell applications.
Thanks for clearing that up. Looks like I totally misunderstood how the {}
syntax works.
Does this only work for Applications/Drivers or for Libraries too so you
don't have to do this for every driver?
I prefer fixing the behavior at build time over implementing a fallback
because it would be weird if the application behaves totally different
depending on if you start it via the BDS or from the Shell.
Thanks
Michael
On Wed, Jul 6, 2016 at 10:20 PM, Carsey, Jaben <[email protected]>
wrote:
> Andrew,
>
>
>
> Note: The ShellLib is not part of the shell spec. The ShellProtocol and
> ShellParametersProtocol are. The current ShellLib is designed to
> facilitate porting and writing of apps for the shell. The porting will
> become obsolete over time as we encounter fewer and fewer EDKShell apps.
>
>
>
> That does’t mean that your conclusion is wrong. We could make a different
> ShellLib that is not actually dependent on the shell.
>
>
>
>
>
> Michael,
>
>
>
> You can have different libs and different flags per driver. You use the
> {} syntax on the INF file in the components section. This is already done
> in the Shell.DSC to control PCDs separating the ShellLib when used for the
> shell compared to ShellLib used for shell applications.
>
>
>
>
>
> -Jaben
>
>
>
>
>
>
>
> *From:* Michael Zimmermann [mailto:[email protected]]
> *Sent:* Wednesday, July 06, 2016 1:13 PM
> *To:* Andrew Fish <[email protected]>
> *Cc:* Marvin Häuser <[email protected]>; [email protected];
> Carsey, Jaben <[email protected]>; [email protected]
> *Subject:* Re: [edk2] StdLib usage for drivers?
> *Importance:* High
>
>
>
> Andrew,
>
>
>
> the problem with multiple library instances is that this does only work
> globally and it gets in your way if you need different versions of a
> dependent library.
>
>
>
> In our case, Applications/Drivers only depend on LibC, an LibC then
> depends on ShellLib which means we'd have to create another LibC instance
> which depends on another version of ShellLib.
>
>
>
> In other words: you can't use the same Library with different build
> options in different drivers built by the same DSC. You'd have to create a
> renamed .inf with different build options which you can't do because your
> driver doesn't depend directly on that lib.
>
>
>
> Thanks
>
> Michael
>
>
>
> On Wed, Jul 6, 2016 at 9:55 PM, Andrew Fish <[email protected]> wrote:
>
>
>
> On Jul 6, 2016, at 12:44 PM, Michael Zimmermann <[email protected]>
> wrote:
>
>
>
> Andrew,
>
>
>
> sry for not reasing the Shell Spec but I think you can answer this faster.
>
> Does the Spec prevent implementing such a 'pure-EFI' fallback by default
> so we can use the same ShellLib globally?
>
>
>
>
>
> Michael,
>
>
>
> If I remember correctly the Shell Spec specifies how the shell functions
> and what protocols it produces that other code can depend on.
>
>
>
> and follow-up question: Libraries are not compiled multiple times right?
> so If I would specify additional CFLAGs these would only be used to build
> your package and not for the libraríes you are using right?
>
>
>
>
>
> The edk2 has the concept of library instances. The DSC file for the
> platform picks the instance of the library for the Module Type. Basically
> ShellLib.h would be the public API and ShellLib is the library class. The
> library class is the public API and it is names in the [Defines] section of
> the libraries INF file via LIBRARY_CLASS =. The build system is smart
> enough to only build the libraries that are actually being used.
>
>
>
> For example this would be the line in the DSC:
>
> ShellLib|ShellPkg/Library/UefiShellLib/UefiShellLib.inf
>
>
>
> And you could change it to:
>
> ShellLib | AltPathToUefiShellLib/AltUefiShellLib.inf
>
>
>
> The upside to all this is the same reason we introduced the concept of
> library classes in the 1st place, you can change the behavior of the StdLib
> without modifying any of the code in the standard lib. This would be a good
> way to experiment and if you get it working I guess it could get added to
> the StdLib at some point as an alternate way to build it.
>
>
>
> Thanks,
>
>
>
> Andrew Fish
>
>
>
> If that's correct then we should stay away from changing ShellLib's
> behavior using cflags in your DSC because it would prevent building both
> shell and efi users of ShellLib with one DSC file.
>
>
>
> Thanks,
>
> Michael
>
>
>
> On Wed, Jul 6, 2016 at 9:25 PM, Andrew Fish <[email protected]> wrote:
>
>
> > On Jul 4, 2016, at 11:17 AM, Marvin Häuser <[email protected]>
> wrote:
> >
> > Daryl, Jaben,
> >
> > As you are the package maintainers of StdLib, could you please comment
> on the situation?
> > If modifications to have StdLib working for drivers are welcome, I would
> offer my help in cleaning up the existing stuff and/or write my own
> patches, though of course there is little point if there is no reaction
> from the reviewers.
> > If it is of any interest, I want to write a shim library for Capstone
> and would prefer not to have three copies of Std functions in my tree
> (StdLib, CryptoPkg (SSL) and Capstone), but rather an improved StdLib that
> works for all.
> >
> > Thanks to those who have offered alternative solutions, but I prefer to
> keep it ‚clean‘ and have the libraries shipping with EDK2 work. :)
> >
>
> Marvin,
>
> It looks like the StdLib has a dependency on the ShellLib and
> ShellCEntryLib. One option would be to implement a new instance of the
> ShellLib and the ShellCEntryLib that don't depend on the Shell. You can get
> a template of how to do file operations from here:
> https://github.com/tianocore/edk2/blob/master/EmbeddedPkg/Library/EfiFileLib/EfiFileLib.c
>
> You would have a couple of options. You good go with the EfiFileLib volume
> synatax, you could just do pure EFI (unclear how to specify a volume
> (driver letter)). You could also just add code to fallback if you can't
> find the shell protocols to due more pure EFI stuff. That way you don't
> need to modify the StdLib just how you build the StdLib from the DSC.
>
> For example you could implement the functions in the ShellLib that the
> StdLib requires and use something like the EfiFileLib to make it easier. I
> think ShellCEntryLib would just be a copy of
> https://github.com/tianocore/edk2/tree/master/MdePkg/Library/UefiApplicationEntryPoint
>
> Thanks,
>
> Andrew Fish
>
>
> > Regards,
> > Marvin.
> >
> > From: Michael Zimmermann [mailto:[email protected]]
> > Sent: Thursday, June 23, 2016 5:32 AM
> > To: Marvin Häuser <[email protected]>
> > Cc: [email protected]; [email protected]
> > Subject: Re: [edk2] StdLib usage for drivers?
> >
> > well for the patch to go upstream it would have to get improved a lot.
> > I've tried to implement this in a way that doesn't need a different dsc
> but the problem is that ShellLib's constructor ASSERT's if it can't find
> the shell protocol and removing that would probably be against the spec's.
> >
> > Also it appears that the StdLib maintainers are kinda busy because most
> of the StdLib patches I've sent to this mailing list didn't get reviewed.
> >
> > Thanks
> > Michael
> >
> > On Wed, Jun 22, 2016 at 10:37 PM, Marvin Häuser <
> [email protected]<mailto:[email protected]>> wrote:
> > Hey Michael,
> >
> > Thank you for your input! This looks interesting.
> > Maybe it would be a good idea to provide the libraries that depend on
> Shell (in master) with functions that call ASSERT (FALSE); for drivers? I
> do not need file I/O, so I think your modifications might work out well for
> me. Would be very nice of course if such changes found their way upstream.
> :)
> >
> > And thank you very much for your comment as well, Andrew! It makes sense
> that StdLib is primarily targeted at porting console applications to UEFI
> Shell.
> >
> > Regards,
> > Marvin.
> >
> > From: Michael Zimmermann [mailto:[email protected]<mailto:
> [email protected]>]
> > Sent: Wednesday, June 22, 2016 10:28 PM
> > To: Marvin H?user <[email protected]<mailto:
> [email protected]>>
> > Cc: [email protected]<mailto:[email protected]>
> > Subject: Re: [edk2] StdLib usage for drivers?
> >
> > In my fork of edk2 I've added support for using StdLib without the Shell.
> > It's quite hacky(setenv/getenv are stubs, no File IO and maybe other
> things hidden by linker GC and me not using all features).
> >
> > But depending on which StdLib features you need this can work pretty
> good.
> >
> > here's the commit that does the magic:
> >
> https://github.com/efidroid/edk2/commit/bf7a296718486bafaf774ea8bcf187c162c3c167
> >
> > and this is how you convert a Shell project to a NonShell one:
> >
> https://github.com/efidroid/uefi_apps_EFIDroidUi/commit/23f0fa08108b8f852564fae733c6a7bce62e2070
> >
> > as you can see it works by using StdLib with different libraries/cflags
> so you have to compile your driver separately if there are other modules
> which need the normal StdLib.
> >
> > Thanks
> > Michael
> >
> > On Wed, Jun 22, 2016 at 9:38 PM, Marvin H?user <
> [email protected]<mailto:[email protected]><mailto:
> [email protected]<mailto:[email protected]>>> wrote:
> > Dear EDK2 developers,
> >
> > For an experimental project, I'm currently attempting to write a library
> wrapper for the disassembler library 'Capstone' in a similar manner to
> CryptoPkg's OpensslLib. As most C libraries, it also depends on the
> standard headers, which are not provided by 'stock' EDK2. My first guess
> has been to use StdLib, though its description states:
> > 'Due to the execution environment built by the StdLib component,
> execution as a UEFI driver can cause system stability issues.'
> >
> > Inspecting OpensslLib I discovered that CryptoPkg deploys its own
> include files for StdLib. Though, from your experience, what are the issues
> with using StdLibPkg with DXE/UEFI drivers? It might be nice to reduce
> duplicate code, though I honestly don't know anything about StdLibPkg and
> its implementation and would be thankful for some insight on that manner.
> >
> > Thank you in advance for your time!
> >
> > Regards,
> > Marvin.
> > _______________________________________________
> > edk2-devel mailing list
> > [email protected]<mailto:[email protected]><mailto:
> [email protected]<mailto:[email protected]>>
> > https://lists.01.org/mailman/listinfo/edk2-devel
> >
> > _______________________________________________
> > edk2-devel mailing list
> > [email protected]<mailto:[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
