Re: writing EDK compatible application.

[Rod Smith <rodsmith@rodsbooks.com>]

On 07/04/2017 04:10 PM, Laszlo Ersek wrote:
> On 07/04/17 19:20, Amit kumar wrote:
>>
>> HI,
>>
>> I have written a code (say helloworld program ) using edk2 framework, named the output efi file as BOOTx64.efi and placed it on a removable media in EFI/BOOT/ directory so that the application is listed in one time boot menu. When selected from boot menu it prints "Hello World".
>> Which works as expected when tested on UEFI 2.3 and above platforms.
>> But the same code fails to execute on EFI 1.10 platforms. Which i suppose is the problem with application entry point.
>> Can somebody suggest me a way so that the application entry function can be compatible to both the platform. Even when written according to UEFI 2.5+ Spec ?
> 
> I don't think you can develop for EFI 1 using edk2 -- unless you use
> EdkCompatibilityPkg I guess. But, I don't know how much
> EdkCompatibilityPkg is maintained.

Actually, I think it is possible -- or at the very least, it's possible
to write something that works on both UEFI-based PCs and EFI 1.1-based
Macs. My rEFInd (https://sourceforge.net/projects/refind/) does this.
I've used it with Macs as early as a first-generation 32-bit Mac Mini. I
have NOT tested it with any non-Apple EFI 1.x implementations, though. I
recall I had to fiddle with the .inf file to get it to work with Macs.
Comparing my refind.inf to other .inf files included in EDK2, I think
the relevant line(s) were one or both of the following:

  EDK_RELEASE_VERSION		= 0x00020000
  EFI_SPECIFICATION_VERSION	= 0x00010000

This is in the [Defines] section.

Note that, if you want to look more closely at the rEFInd code or
configuration files, I've made some significant improvements to the
compilation procedures under EDK2 (vs. GNU-EFI) since the latest 0.10.8
release. Thus, you should pull down the latest unreleased code via git,
rather than download the source code tarball.

-- 
Rod Smith
rodsmith@rodsbooks.com
http://www.rodsbooks.com