How do I use “argc” in an efi shell?

Question

Currently I am programming with efi API.

How do I use in an efi programing ? I want to know how to write argv and argc in efi.

c code written till now:

#include <stdio.h>
int main(int argc,char *argv[])
{
  int i;
  printf("Program name is %s \n",argv[0]);
  if (argc <2)
     printf("argument is no exist \n");
 else 
   for (i=0;i<argc;i++)
     printf ("argv[%d] = %s \n",i,argv[i]);
 }

Answer 1

argc , argv and main are standard library concepts, and don't directly translate to UEFI applications.

On a generic level:

• UEFI applications use only UEFI interfaces
• UEFI Shell applications can also rely on interfaces provided by the UEFI Shell (but will not run correctly outside the shell)

In either case, when the application launches, its entry point will only be passed a pointer to the UEFI System Table and an Image Handle , providing the link to information about how the current image was invoked.

Pure UEFI applications have only the EFI_LOADED_IMAGE_PROTOCOL installed on their image handle. UEFI Shell applications also have the EFI_SHELL_PARAMETERS_PROTOCOL .

The EFI_SHELL_PARAMETERS_PROTOCOL gives you access to argc/argv constructs. Without this, you're down to parsing EFI_LOADED_IMAGE_PROTOCOL.LoadOptions manually.

You can find the details of these protocols in the UEFI Specification and the UEFI Shell Specification , from the UEFI Forum website .

Of course, abstracting frameworks like gnu-efi (and maybe VisualUefi) may hide the underlying mechanics, or provide alternative means for getting at them.`