sunxi-errors-dat

• sunxi-log-dat

Unable to mount root fs on unknown-block

[    3.170114] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) ]---

Error Meaning

• VFS: Unable to mount root fs → Kernel started but could not find or mount the root filesystem.
• unknown-block(0,0) → Kernel didn’t find the block device for rootfs (often means missing drivers or wrong parameters).

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Common Causes

Cause	Explanation
Incorrect rootfs path in bootloader	Kernel parameter root= may point to a wrong device.
Missing storage drivers	Kernel was built without drivers for your storage device (SD card, eMMC, SATA, etc.).
Corrupted root filesystem	Root filesystem may be damaged or missing.
Wrong DTB (Device Tree Blob)	Device tree does not match hardware, so root device isn’t recognized.
Wrong kernel configuration	Missing CONFIG support for your filesystem type (ext4, squashfs, etc.).

On Sunxi devices (Allwinner), bootloader is usually u-boot or barebox.

• Look at the boot command in boot.cmd or boot.scr.
• Check the root= parameter:

Here:

• /dev/mmcblk0p2 means second partition of SD/eMMC.
• rootwait → wait for device to be ready.

Possible issues:

• Wrong partition number.
• Missing rootwait (device might not be ready when kernel tries to mount).