What is UEFI Variable Store?
Quick note explaining UEFI Variable Store for BIOS/UEFI and embedded firmware readers.
What is UEFI Variable Store?
UEFI Variable Store is a BIOS/UEFI firmware concept used when reading firmware source code, logs, or specifications.
Why it matters
- Explains how firmware stores settings across reboots.
- Helps debug lost setup settings, boot-order issues, and variable-store problems.
- Clarifies the difference between legacy CMOS concepts and modern UEFI variables.
Practical example
Example: if BIOS settings disappear after power removal, check the RTC/CMOS battery, NVRAM persistence, and whether the variable store is being reset.
Quick checklist
- Does the variable persist after reboot and power-off?
- Is the variable store full or corrupted?
- Does Clear CMOS/NVRAM reset change the behavior?
Quick takeaway
UEFI Variable Store is a small concept, but it often becomes important when reading logs or debugging real firmware.
Related notes
- What is Variable Attribute?
- What is NVRAM?
- What is Runtime Services?
- What is Variable Store Full?
- What is UEFI Variable?
Public references
- UEFI Specification 2.11 — Runtime Services
- UEFI Specification 2.11 — Boot Manager / NVRAM variables
- EDK II — VariableRuntimeDxe
Found this useful?
Save it or share it with someone learning firmware, BIOS/UEFI, and embedded systems.
Nội dung liên quan
Một số bài viết, ghi chú hoặc project có liên quan đến nội dung bạn vừa đọc.
What is BIOS Setup Variable?
Quick note explaining BIOS Setup Variable for BIOS/UEFI and embedded firmware readers.
What is BootCurrent?
Quick note explaining BootCurrent for BIOS/UEFI and embedded firmware readers.
What is EFI System Partition?
Quick note explaining EFI System Partition for BIOS/UEFI and embedded firmware readers.
Biến note thành bài viết hoàn chỉnh
Notes là nơi ghi nhanh khái niệm.