Looking at public photos of the VisionFive 2 board, I see what might be a VLI VL805-06 chip near the 4 USB 3.0 ports.
VLI VL805 (4-Port Super Speed USB 3.0 Host controller with a PCIe interface)
https://www.via-labs.com/product_show.php?id=48
- Firmware upgrade options include integrated firmware in system BIOS (I’m guessing would allow OS booting from USB storage devices).
Software:
- Initial Driver Support for Windows 7, Vista, and XP
- USB Attached SCSI Protocol (UASP)
- Supports various Linux kernels
- Supports Windows 10, Windows 8 inbox driver
Access to the firmware, documentation, and code I would imagine requires signing an NDA, since there is no public datasheet or even brochure, for this VLI confidential information.
There is some public Linux code for the RPi4 which uploads the VL805 firmware blob via a mailbox request to the Videocore OS in the event of a reset, using non public firmware load logic.
So even though basic xHCI functionality can be got to work (if the VL805 loads its own firmware from say an external EEPROM), some possible features may never be added like the ability to boot an OS from a USB storage device, simply because the NDA’s limit access to the knowledge required. And none of information can be made public, so you could end up with a firmware blob that is installed once and never updated.
I should probably add that is not part of the JH7110 SoC.