Huawei S7721u Recovery Image Verify Failed: Repack Best

This is a technical advisory paper regarding the resolution of the error encountered when flashing a repacked recovery image on Huawei S7721U series switches (and similar EdgeCore rebadges).

After reboot, check:

Huawei devices use a verified boot system. When you modify or "repack" a recovery image, the original cryptographic signature is lost. Unless the bootloader is unlocked, it will reject any image that doesn't match the official Huawei signature. How to Fix the Verification Failure 1. Restore Official Firmware via eRecovery huawei s7721u recovery image verify failed repack

If RSA‑signed (common on Huawei):

typically occurs when the device's bootloader detects a recovery image that is corrupted, incorrectly signed, or has been modified through an unauthorized "repack" . This security feature prevents the system from booting into a compromised or incompatible environment. Understanding the "Repack" Failure This is a technical advisory paper regarding the

Before attempting any fixes, it's crucial to identify what triggered the error. The most common causes include:

The Huawei S7721u community has documented several workarounds for persistent verification errors. Many users report success with: Unless the bootloader is unlocked, it will reject

crc32 recovery_nosig.img > new_crc.bin # Overwrite old CRC location (find via hexdump) dd if=new_crc.bin of=recovery_nosig.img bs=1 seek=<CRC_offset> conv=notrunc

This will create a new, repacked recovery image with the modified verification components.

Press and hold for about 15 seconds to enter eRecovery mode.

: If you have "repacked" a recovery image, the original cryptographic signature is broken. Huawei's bootloader strictly checks these signatures; if they don't match the authorized official keys, the verification will fail. Corrupted Download : An incomplete or damaged UPDATE.APP file will fail parsing and verification. Storage Media Issues