On Sat, Nov 20, 2021 at 01:54:30PM +0100, Heinrich Schuchardt wrote:
Hello Takahiro,
in a prior mail we have discussed the creation of device paths for USB mass storage devices.
On the sand boxyou get the following devices after 'usb start':
Class Index Probed Driver Name
usb 0 [ + ] usb_sandbox |-- usb@1 usb_hub 0 [ + ] usb_hub | `-- hub usb_mass_s 0 [ + ] usb_mass_storage | |-- usb_mass_storage blk 3 [ ] usb_storage_blk | | `-- usb_mass_storage.lun0 usb_mass_s 1 [ + ] usb_mass_storage | |-- usb_mass_storage blk 4 [ ] usb_storage_blk | | `-- usb_mass_storage.lun0 usb_mass_s 2 [ + ] usb_mass_storage | `-- usb_mass_storage blk 5 [ ] usb_storage_blk | `-- usb_mass_storage.lun0
For of these storage devices we try to create the same device path which is not allowable:
=> usb start starting USB... Bus usb@1: scanning bus usb@1 for devices... 5 USB Device(s) found scanning usb for storage devices... 3 Storage Device(s) found => => efidebug dh Scanning disk mmc2.blk... handle 0000000015e34f00, /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/SD(2)/SD(0) Scanning disk mmc1.blk... handle 0000000015e36b30, /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/SD(1)/SD(1) Scanning disk mmc0.blk... handle 0000000015e35b00, /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/SD(0)/SD(2) Scanning disk usb_mass_storage.lun0... handle 0000000015e35c10, /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/UsbClass(0x1234,0x5678,0x9,0x0,0x0)/UsbClass(0x1234,0x5678,0x0,0x0,0x0) fs_devread read outside partition 2 Failed to mount ext2 filesystem... BTRFS: superblock end 69632 is larger than device size 512 Scanning disk usb_mass_storage.lun0... handle 0000000015e361f0, /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/UsbClass(0x1234,0x5678,0x9,0x0,0x0)/UsbClass(0x1234,0x5678,0x0,0x0,0x0) ERROR: failure to add disk device usb_mass_storage.lun0, r = 20 Error: Cannot initialize UEFI sub-system, r = 20
I will provide a patch that will allow the first USB device to be used and avoids stopping the boot process. But we really have to walk the dm tree to create a device patch for USB devices based on port IDs.
We should add a new field to struct uclass_driver:
struct efi_device_path *get_node(udevice *dev);
This function shall return a pointer to an freshly allocated buffer with the device node for the device. To build the devicepath we can then walk the dm tree.
I'm not sure this is an acceptable solution.
Let me make sure: The goal would be to create a device path like .../USB(0x1,0x0)/HD(1,...) instead of .../UsbHub(0x0,0x0,0x0,0x3)/UsbMassStorage(0x46f4,0x1,0x0,0x0)/HD(1,...) as we already see this format for SCSI: .../Scsi(0,0)/HD(1,..)
Right?
-Takahiro Akashi
To make migration easier: If the function pointer or the return value is NULL we can create a CTRL() node as dummy using the uclass_id and the device number.
Best regards
Heinrich