Capturing Stdio of an image loaded using EFI_BOOT_SERVICES.LoadImage()

Capturing Stdio of an image loaded using EFI_BOOT_SERVICES.LoadImage()

[Ayush Singh]

Hello everyone. So while trying to make Rust `remote-test-server`, I 
found out that it also needs to be able to launch other UEFI 
applications (which will be the tests themselves). The Stdout and Stderr 
of these tests is supposed to be captured and sent back to the 
`remote-test-client` over TCP. I can now launch the `remote-test-server` 
under UEFI and get it to connect to the `remote-test-client`, however 
the application launch stuff isn't implemented yet.

While I think I can implement the launching application portion using 
the `EFI_BOOT_SERVICES.LoadImage()` and `EFI_BOOT_SERVICES.StartImage()` 
functions, I do not know how to capture the input/output of these 
applications. So is there a way to do it normally? I think UefiShell 
must do this, but I am not sure how.

Currently I do have a way to capture output when specifically running 
tests (basically writing the output and errors to a file and reading 
from it). However, that seems more like a hack, and so I wanted to know 
if there was a better way to do this.


Yours Sincerely

Ayush Singh