FreeBSD 12 – UEFI boot fails after disk clone because EFI partition bootcode is missing

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

System drops to firmware shell after reboot from cloned disk.

Environment & Reproduction

Occurs when ESP content/NVRAM entries are missing after migration.

Root Cause Analysis

UEFI cannot find valid loader path on EFI System Partition.

Quick Triage

Verify boot mode, ESP mount status, and loader file presence.

Step-by-Step Diagnosis

Inspect partition layout, ESP filesystem health, and boot entries.

Solution – Primary Fix

Mount ESP, copy loader to fallback path, recreate UEFI boot entry.

Solution – Alternative Approaches

Use fallback BOOTX64.EFI path when NVRAM writes are restricted.

Verification & Acceptance Criteria

System repeatedly boots into FreeBSD 12 from cloned disk.

Rollback Plan

Select previous boot disk/entry and restore known-good firmware path.

Prevention & Hardening

Include ESP copy and efiboot validation in clone runbooks.

Related Errors & Cross-Refs

Related to GPT attribute mismatch and stale root pool hints.

Related tutorial: View the step-by-step tutorial for FreeBSD 12.

View all FreeBSD 12 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

FreeBSD UEFI boot handbook, gpart docs, and efibootmgr usage.