Run a UEFI shell command from inside UEFI application

Question

I'm new to UEFI application development.

My requirement is that,

I need to run an UEFI shell command from my UEFI application (app.efi) source code. Need guidance on how I can do this.

Example,

cp command in UEFI shell is used to copy a file from one path to another. I want to do this programmatically inside my application (app.efi) source code.

EDIT: I'm looking for something similar to system("command"); function in Linux.

How to achieve this?

Answer 1

Calling a UEFI shell command from a UEFI application can be done using the EFI_SHELL_EXECUTE function of EFI_SHELL_PROTOCOL, defined under MdePkg/Include/Protocol/Shell.h.

You need to include the protocol GUID in the inf file of your UEFI application:

[Protocols]
  gEfiShellProtocolGuid                  ## CONSUMES

Then you can call a shell command like in the following example:

EFI_STATUS
EFIAPI
UefiMain (
  IN EFI_HANDLE                            ImageHandle,
  IN EFI_SYSTEM_TABLE                      *SystemTable
  )
{
  EFI_SHELL_PROTOCOL    *EfiShellProtocol;
  EFI_STATUS            Status;

  Status = gBS->LocateProtocol (&gEfiShellProtocolGuid,
                                NULL,
                                (VOID **) &EfiShellProtocol);

  if (EFI_ERROR (Status)) {
    return Status; 
  }

  EfiShellProtocol->Execute (&ImageHandle,
                             L"echo Hello World!",
                             NULL,
                             &Status);

  return Status;
}

EDIT: There's an easier (and probably a more correct) way of doing it using ShellLib Library Class:

#include <Library/ShellLib.h>

EFI_STATUS
EFIAPI
UefiMain (
  IN EFI_HANDLE                            ImageHandle,
  IN EFI_SYSTEM_TABLE                      *SystemTable
  )
{
  EFI_STATUS            Status;

  ShellExecute (&ImageHandle,
                L"echo Hello World!",
                FALSE,
                NULL,
                &Status);

  return Status;
}