Don't fail capsule update if a monitor isn't plugged in #1733
Description
The problem you're addressing (if any)
Currently in terms of capsule update and graphical output, there seems to be two options, depending on the CONFIG_EDK2_GRAPHICAL_CAPSULE_PROGRESS flag state:
- If it's set, a screen must be plugged into the platform during a capsule update, so that the progress bar can be displayed. If it's unplugged, the update will fail/abort.
- If it's unset, a screen may or may not be plugged in. The progress will be printed over the serial console (and on the screen in text mode?), and the update will be successful either way.
Describe the solution you'd like
If the flag is set, the graphical progress bar should be preferred but the text/serial mode should be used as a fallback if a screen is unavailable, rather than the update failing.
Where is the value to a user, and who might that user be?
The user might decide/have to start using their platform in headless mode at some point, they shouldn't be locked out of a capsule update at compile time.
Describe alternatives you've considered
It's not impossible to imagine a corner case where a user turns on a capsule update, isn't plugged into serial and somehow their monitor stops working/gets disconnected. In such case the user might try resetting during an update, in effect bricking the platform.
To guard against such case, we may add a console prompt like This is capsule update, running in text mode as a fallback. Press 5 to confirm and continue.
Additional context
No response