Re: How to get fs index from controller handle.

[Andrew Fish <afish@apple.com>]

> On Apr 6, 2017, at 1:30 PM, Carsey, Jaben <jaben.carsey@intel.com> wrote:
> 
> That's the way to do it.  the hard work is around finding the DevicePath for the application you want to run to pass to LoadImage.
> 

Jaben,

It was easy in the old days.....

DevPath  = gSE2->NameToPath (ShellPathName);
gSE2->GetFsName (DevPath, FALSE, & ShellPathName);

Maybe we should default EFI_SHELL_ENVIRONMENT2 to on :)? Half joking. 

I used those 2 APIs in the past to glue in shell volume names to a really simplistic C lib. 

Also if you have the File System Handle and path you can use the DevicePathLib.

/**
  Allocates a device path for a file and appends it to an existing device path.

  If Device is a valid device handle that contains a device path protocol, then a device path for
  the file specified by FileName  is allocated and appended to the device path associated with the
  handle Device.  The allocated device path is returned.  If Device is NULL or Device is a handle
  that does not support the device path protocol, then a device path containing a single device
  path node for the file specified by FileName is allocated and returned.
  The memory for the new device path is allocated from EFI boot services memory. It is the responsibility
  of the caller to free the memory allocated.
  
  If FileName is NULL, then ASSERT().
  If FileName is not aligned on a 16-bit boundary, then ASSERT().

  @param  Device                     A pointer to a device handle.  This parameter is optional and
                                     may be NULL.
  @param  FileName                   A pointer to a Null-terminated Unicode string.

  @return The allocated device path.

**/
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
FileDevicePath (
  IN EFI_HANDLE                      Device,     OPTIONAL
  IN CONST CHAR16                    *FileName
  );


Thanks,

Andrew Fish

>> -----Original Message-----
>> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org <mailto:edk2-devel-bounces@lists.01.org>] On Behalf Of
>> Amit kumar
>> Sent: Thursday, April 06, 2017 9:45 AM
>> To: Andrew Fish <afish@apple.com <mailto:afish@apple.com>>
>> Cc: edk2-devel@lists.01.org <mailto:edk2-devel@lists.01.org>
>> Subject: Re: [edk2] How to get fs index from controller handle.
>> Importance: High
>> 
>> Hi,
>> 
>> 
>> Can i use gbs->loadimage() and gbs->startimage() to load an efi application
>> and execute it.
>> 
>> Suppose i have a app1.efi and from app1.efi i want to execute app2.efi.
>> 
>> Or is there some other way to do it ?
>> 
>> Not considering ShellExecute();
>> 
>> Amit
>> 
>> ________________________________
>> From: afish@apple.com <mailto:afish@apple.com> <afish@apple.com <mailto:afish@apple.com>> on behalf of Andrew Fish
>> <afish@apple.com <mailto:afish@apple.com>>
>> Sent: Thursday, April 6, 2017 4:39:22 PM
>> To: Amit kumar
>> Cc: edk2-devel@lists.01.org <mailto:edk2-devel@lists.01.org>
>> Subject: Re: [edk2] How to get fs index from controller handle.
>> 
>> 
>> On Apr 6, 2017, at 3:30 AM, Amit kumar
>> <akamit91@hotmail.com <mailto:akamit91@hotmail.com><mailto:akamit91@hotmail.com <mailto:akamit91@hotmail.com>>> wrote:
>> 
>> Hi,
>> 
>> I want to get the fs index from the controller handle.
>> e.g In map command i see my controller is mapped to fs10.
>> So i there any API i can use in my code to get the fs index( which is 10 as in
>> example) from the controller handle.
>> 
>> 
>> Amit,
>> 
>> It is important to remember that fs0:, and the other device names are a Shell
>> concept and not an EFI concept. So they only exist in the context of the shell.
>> 
>> I took a quick look and I did not see an easy way to do this with the current
>> Shell APIs.
>> 
>> In the older Shell you could use this  protocol  EfiShellEnvironment2 Protocol
>> has a function that converts a EFI_DEVICE_PATH_PROTOCOL (would be on
>> your controller handle) to a CHAR16. Thus you can get the volume name the
>> Shell would display to the user. I don't the index exists as a concept.  So
>> EFI_SHELL_ENVIRONMENT2.GetFsName() and
>> EFI_SHELL_ENVIRONMENT2.GetFsDevicepath() are the closest thing I can
>> think of.
>> https://github.com/tianocore/edk2/blob/master/ShellPkg/Include/Protocol/ <https://github.com/tianocore/edk2/blob/master/ShellPkg/Include/Protocol/>
>> EfiShellEnvironment2.h#L812
>> 
>> The only problem with that is EfiShellEnvironment2 is not produced by the
>> Shell by default.
>> 
>>  ## This flag is used to control the protocols produced by the shell
>>  #  If TRUE the shell will produce EFI_SHELL_ENVIRONMENT2 and
>> EFI_SHELL_INTERFACE
>> 
>> gEfiShellPkgTokenSpaceGuid.PcdShellSupportOldProtocols|FALSE|BOOLEAN
>> |0x00000002
>> 
>> I've use the EFI_SHELL_ENVIRONMENT2 in the past to enable a non Shell
>> application to print out volume names that match the map command of the
>> shell. Hopefully some one knows how to do this in the modern Shell?
>> 
>> Thanks,
>> 
>> Andrew Fish
>> 
>> Regards
>> Amit
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