For most S7721U variants, the "repack" error occurs due to , not necessarily RSA. The bootloader calculates a simple 32-bit XOR or CRC over the image. By using the original header and ensuring identical size, you often satisfy the check.
Hold to enter FastBoot mode (indicated by a robot screen).
: Repacking tools alter the exact file byte count, failing the basic hardware checksum checks during start-up. huawei s7721u recovery image verify failed repack
: Slide the MicroSD card safely back into the tablet slot. Hold down the Volume Up + Volume Down + Power buttons simultaneously from a completely powered-down state. Release them only when the systemic progress bar shows up on screen. Step 3: Avoiding Broken Repacks in the Future
Method 1: The Fastboot Workaround (Restoring Stock Recovery) For most S7721U variants, the "repack" error occurs
fastboot oem get-bootinfo
In U-Boot:
If you are stuck in a boot loop or cannot pass the verification, follow these steps to restore functionality. Method A: Use Official Firmware (No Repack)
Mount it (or use unsquashfs ):