Re: LocateHandle for gEfiShellProtocolGuid is failing in my application

["Carsey, Jaben" <jaben.carsey@intel.com>]

That function is not in the shell library.

LocateHandle would be useful is you wanted to find the image handle for the shell binary whereas LocaetProtocol would be just getting a pointer to the protocol.

Which version of the UEFI Shell are you using?  (what does “ver” command say)

-Jaben

From: GN Keshava [mailto:keshava.gn@gmail.com]
Sent: Thursday, December 22, 2016 2:07 AM
To: Carsey, Jaben <jaben.carsey@intel.com>; edk2-devel@lists.01.org
Subject: Re: [edk2] LocateHandle for gEfiShellProtocolGuid is failing in my application
Importance: High

Hi Jaben and Andrew, Thanks for the replies. Here's a small update.

I tried using LocateProtocol, and I get "Status Not Found" (%r would print "Status Not Found").
I'm getting the same error status for LocateHandle too. I'm using BufferSize=0 and Buffer=NULL for getting the BufferSize.
What this would mean? Is there any specific requirement my application should meet, to use ShellProtocol? Or, as I mentioned in previous mail, I want to use GetMapFromDevicePath function. Is there any alternate way to do it?

Thanks for your help.
Regards,
Keshava

On Thu, 22 Dec 2016 at 15:01 GN Keshava <keshava.gn@gmail.com<mailto:keshava.gn@gmail.com>> wrote:
Hi Jaben,

>> Is there a reason that you are not using ShellLib to facilitate your app functionality?  That library makes lots of things a lot easier.

I want to use EFI_SHELL_PROTOCOL->GetMapFromDevicePath in my app. Is there any way to use it using ShellLib ?

>> Why do you use LocateHandle and not LocateProtocol?

Got LocateHandle in my reference. I would like to know more about difference and usage of these in different scenario.

>> Are you running the UEFI Shell and then your application?

Yes. I'm running my application from UEFI shell as :

fs1:\> MyApp.exe Arg1 Arg2

Thanks for the help..

Regards,
Keshava

On Thu, 22 Dec 2016 at 00:06 Carsey, Jaben <jaben.carsey@intel.com<mailto:jaben.carsey@intel.com>> wrote:
Hi Keshava,

few questions:
Is there a reason that you are not using ShellLib to facilitate your app functionality?  That library makes lots of things a lot easier.
Why do you use LocateHandle and not LocateProtocol?
Are you sure about that return code?  Usually most-sig-bit is set for error returns.

Does the following snippet of code find a valid instance?

    Status = gBS->LocateProtocol(
      &gEfiShellProtocolGuid,
      NULL,
      (VOID **)&gEfiShellProtocol
     );
    if (EFI_ERROR(Status)) {
      gEfiShellProtocol = NULL;
    }

Are you running the UEFI Shell and then your application?


-Jaben




> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org<mailto:edk2-devel-bounces@lists.01.org>] On Behalf Of
> GN Keshava
> Sent: Tuesday, December 20, 2016 11:32 PM
> To: edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>
> Subject: [edk2] LocateHandle for gEfiShellProtocolGuid is failing in my
> application
> Importance: High
>
> Hi,
>
> I'm developing a shell application. A call to LocateHandle for
> gEfiShellProtocolGuid is failing with Status 0x0E.
>
> Below is my code. Please let me know what I'm doing wrong.
>
> Status = gBS->LocateHandle(ByProtocol, &gEfiShellProtocolGuid, NULL,
> &BufferSize, Buffer); // Get BufferSize
> if (EFI_ERROR(Status))
> Print(L"LocateHandle Status 0x%x\n",Status);
>
> Status = gBS->AllocatePool(EfiBootServicesData, BufferSize,
> (void**)&Buffer);
> if (EFI_ERROR(Status))
> Print(L"AllocatePool Status 0x%x\n",Status);
>
> Status = gBS->LocateHandle(ByProtocol, &gEfiShellProtocolGuid, NULL,
> &BufferSize, Buffer);
> if (EFI_ERROR(Status))
> Print(L"LocateHandle Status 0x%x\n",Status);
>
> All calls failing with Status being 0x0E. Please help me to solve this. Is
> there any special requirement for using this protocol?
>
> Thanks.
> Regards,
> Keshava
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