What is EFI_OUT_OF_RESOURCES?
Quick note explaining EFI_OUT_OF_RESOURCES for BIOS/UEFI and embedded firmware readers.
EFI_OUT_OF_RESOURCES is a firmware-debugging concept used to understand return status, logs, commands, or failure points.
Why it matters
- Makes UEFI return values easier to interpret.
- Helps write safer error handling in drivers and applications.
- Useful when following service-call failures in debug logs.
Practical example
Example: do not use output parameters after a UEFI API returns an error. Check EFI_STATUS first, then decide whether to retry, allocate a larger buffer, or fail cleanly.
Quick checklist
Quick takeaway
EFI_OUT_OF_RESOURCES is a small concept, but it often becomes important when reading logs or debugging real firmware.
Put it into the system flow
I try not to treat EFI_OUT_OF_RESOURCES as a dictionary entry. I read it as part of a firmware path: who produces it, who consumes it, and what symptom appears when it is wrong. That habit makes the note useful during debugging, not only during study.
A practical picture
In real debugging, more logs do not automatically mean more clarity. I usually mark the last confirmed-good point first, then move forward one boundary at a time. EFI_OUT_OF_RESOURCES is useful when it helps identify that boundary in the log or shell output.
In a real debugging session
EFI_OUT_OF_RESOURCES is most useful when treated as a checkpoint in the log. Instead of asking only what it means, ask what condition creates it, which module returns it, and whether the firmware retries, falls back, or stops after it.
A small log at the right boundary is often better than noisy logs everywhere. Log the input, state before the API call, return status, and the branch taken afterward.
Related notes
- What is Supported() in UEFI Driver Model?
- What is Start() in UEFI Driver Model?
- What is Stop() in UEFI Driver Model?
- What is UEFI Device Driver?
- What is EFI_UNSUPPORTED?
Public references
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