[BUG] efi_loader: incorrect creation of device paths

Heinrich Schuchardt xypron.glpk at gmx.de
Fri Dec 3 17:32:49 CET 2021


On 11/25/21 06:44, AKASHI Takahiro wrote:
> Heinrich,
>
> On Wed, Nov 24, 2021 at 12:10:32PM +0900, AKASHI Takahiro wrote:
>> 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 at 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 at 1: scanning bus usb at 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?
>
> Please try the tweak attached below.
> (I think what I did here is trivial.)
>
> If you like, I will post it as a patch.
> (See "10.3.4.5.1 USB Device Path Example".)
>
> -Takahiro Akashi
>
>>>>  From cda91e9d8144f89f0d73738b338289a7940bbe0e Mon Sep 17 00:00:00 2001
>>>> From: AKASHI Takahiro <takahiro.akashi at linaro.org>
>>>> Date: Thu, 25 Nov 2021 14:20:08 +0900
>>>> Subject: [PATCH] efi_loader: disk: usb mass-storage
>
> - use path_usb instead of path_usb_class for existing USB dp nodes
> - add a dp node for UCLASS_USB
>
> => usb start
> starting USB...
> Bus xhci_pci: Register 8001040 NbrPorts 8
> Starting the controller
> USB XHCI 1.00
> scanning bus xhci_pci for devices... 4 USB Device(s) found
>         scanning usb for storage devices... 2 Storage Device(s) found
> => dm tree
>   Class     Index  Probed  Driver                Name
> -----------------------------------------------------------
>   root          0  [ + ]   root_driver           root_driver
>   ...
>   pci           0  [ + ]   pci_generic_ecam      |-- pcie at 10000000
>   pci_generi    0  [   ]   pci_generic_drv       |   |-- pci_0:0.0
>   virtio       32  [ + ]   virtio-pci.l          |   |-- virtio-pci.l#0
>   ethernet      0  [ + ]   virtio-net            |   |   `-- virtio-net#32
>   usb           0  [ + ]   xhci_pci              |   `-- xhci_pci
>   usb_hub       0  [ + ]   usb_hub               |       `-- usb_hub
>   usb_dev_ge    0  [ + ]   usb_dev_generic_drv   |           |-- generic_bus_0_dev_2
>   usb_mass_s    0  [ + ]   usb_mass_storage      |           |-- usb_mass_storage
>   blk           0  [   ]   usb_storage_blk       |           |   `-- usb_mass_storage.lun0
>   usb_mass_s    1  [ + ]   usb_mass_storage      |           `-- usb_mass_storage
>   blk           1  [   ]   usb_storage_blk       |               `-- usb_mass_storage.lun0
>   ...
> => efidebug devices
> Scanning disk usb_mass_storage.lun0...
> Scanning disk usb_mass_storage.lun0...
> Found 6 disks
> Missing RNG device for EFI_RNG_PROTOCOL
> ** Unable to read file ubootefi.var **
> Failed to load EFI variables
> Unable to find TPMv2 device
> Device           Device Path
> ================ ====================
> 000000013eef3a50 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)
> 000000013eefe840 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/USB(0xf3,0x0)/USB(0x0,0x0)/USB(0x2,0x0)
> 000000013eefe990 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/USB(0xf3,0x0)/USB(0x0,0x0)/USB(0x2,0x0)/HD(1,0x01,0,0x0,0x99800)
> 000000013eefeae0 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/USB(0xf3,0x0)/USB(0x0,0x0)/USB(0x2,0x0)/HD(2,0x01,0,0x99800,0x1800)
> 000000013eeff5f0 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/USB(0xf3,0x0)/USB(0x0,0x0)/USB(0x3,0x0)
> 000000013eeff990 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/USB(0xf3,0x0)/USB(0x0,0x0)/USB(0x3,0x0)/HD(1,GPT,ce86c5a7-b32a-488f-a346-88fe698e0edc,0x22,0x4c2a)
> 000000013eeffda0 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/USB(0xf3,0x0)/USB(0x0,0x0)/USB(0x3,0x0)/HD(2,GPT,aa80aab9-33e6-42b6-b5db-def2cb8d7844,0x5000,0x1a800)

I am missing a PCI() node here for the USB root Hub. In the DM tree: Is
xhci_pci the root hub and usb_hub a hub connected to this root hub? Or
do both nodes together model a root hub? Anyway USB(0xf3,0x0) seems to
be wrong. There is no USB hub with a port 243.

Please, see the examples on p. 303ff of the UEFI 2.9 specification:

PciRoot(0)/PCI(31,2)/USB(0,0)
PciRoot(0)/PCI(31,2)/USB(1,0)/USB(3,0)

The first example is a USB controller connected to port 0 of the root hub.
The second is a USB controller connected to port 3 of a USB hub which is
connected to port 1 of the root hub.

Best regards

Heinrich

> 000000013ef00270 /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/MAC(525252525252,1)
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> ---
>   lib/efi_loader/efi_device_path.c         | 36 ++++++++++++++++++++++--
>   lib/efi_loader/efi_device_path_to_text.c | 17 ++++++++---
>   2 files changed, 47 insertions(+), 6 deletions(-)
>
> diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
> index 735ed0bd0f4c..a8ec6809c422 100644
> --- a/lib/efi_loader/efi_device_path.c
> +++ b/lib/efi_loader/efi_device_path.c
> @@ -557,10 +557,18 @@ __maybe_unused static unsigned int dp_size(struct udevice *dev)
>   		return dp_size(dev->parent) +
>   			sizeof(struct efi_device_path_sd_mmc_path);
>   #endif
> +#if 1
> +	case UCLASS_USB:
> +	case UCLASS_USB_HUB:
> +	case UCLASS_MASS_STORAGE:
> +		return dp_size(dev->parent) +
> +			sizeof(struct efi_device_path_usb);
> +#else
>   	case UCLASS_MASS_STORAGE:
>   	case UCLASS_USB_HUB:
>   		return dp_size(dev->parent) +
>   			sizeof(struct efi_device_path_usb_class);
> +#endif
>   	default:
>   		/* just skip over unknown classes: */
>   		return dp_size(dev->parent);
> @@ -740,6 +748,24 @@ __maybe_unused static void *dp_fill(void *buf, struct udevice *dev)
>   		return &sddp[1];
>   	}
>   #endif
> +#if 1
> +	case UCLASS_USB:
> +	case UCLASS_USB_HUB:
> +	case UCLASS_MASS_STORAGE: {
> +		struct efi_device_path_usb *udp =
> +			dp_fill(buf, dev->parent);
> +		struct usb_device *udev = dev_get_parent_priv(dev);
> +
> +		udp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
> +		udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
> +		udp->dp.length   = sizeof(*udp);
> +		udp->parent_port_number = udev->portnr;
> +		/* TODO: see usb_new_device() */
> +		udp->usb_interface = 0;
> +
> +		return &udp[1];
> +	}
> +#else
>   	case UCLASS_MASS_STORAGE:
>   	case UCLASS_USB_HUB: {
>   		struct efi_device_path_usb_class *udp =
> @@ -750,14 +776,20 @@ __maybe_unused static void *dp_fill(void *buf, struct udevice *dev)
>   		udp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
>   		udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
>   		udp->dp.length   = sizeof(*udp);
> -		udp->vendor_id   = desc->idVendor;
> -		udp->product_id  = desc->idProduct;
> +#if 1
> +		if (dev->driver->id == UCLASS_MASS_STORAGE)
> +			udp->device_class    = 8;
> +		else if (dev->driver->id == UCLASS_USB_HUB)
> +			udp->device_class    = 9;
> +#else
>   		udp->device_class    = desc->bDeviceClass;
> +#endif
>   		udp->device_subclass = desc->bDeviceSubClass;
>   		udp->device_protocol = desc->bDeviceProtocol;
>
>   		return &udp[1];
>   	}
> +#endif
>   	default:
>   		debug("%s(%u) %s: unhandled device class: %s (%u)\n",
>   		      __FILE__, __LINE__, __func__,
> diff --git a/lib/efi_loader/efi_device_path_to_text.c b/lib/efi_loader/efi_device_path_to_text.c
> index 57fa9d97f712..a21de4157307 100644
> --- a/lib/efi_loader/efi_device_path_to_text.c
> +++ b/lib/efi_loader/efi_device_path_to_text.c
> @@ -158,10 +158,19 @@ static char *dp_msging(char *s, struct efi_device_path *dp)
>   		struct efi_device_path_usb_class *ucdp =
>   			(struct efi_device_path_usb_class *)dp;
>
> -		s += sprintf(s, "UsbClass(0x%x,0x%x,0x%x,0x%x,0x%x)",
> -			ucdp->vendor_id, ucdp->product_id,
> -			ucdp->device_class, ucdp->device_subclass,
> -			ucdp->device_protocol);
> +		if (ucdp->device_class == 8)
> +			s += sprintf(s, "UsbMassStorage(0x%x,0x%x,0x%x,0x%x)",
> +				ucdp->vendor_id, ucdp->product_id,
> +				ucdp->device_subclass, ucdp->device_protocol);
> +		else if (ucdp->device_class == 9)
> +			s += sprintf(s, "UsbHub(0x%x,0x%x,0x%x,0x%x)",
> +				ucdp->vendor_id, ucdp->product_id,
> +				ucdp->device_subclass, ucdp->device_protocol);
> +		else
> +			s += sprintf(s, "UsbClass(0x%x,0x%x,0x%x,0x%x,0x%x)",
> +				ucdp->vendor_id, ucdp->product_id,
> +				ucdp->device_class, ucdp->device_subclass,
> +				ucdp->device_protocol);
>
>   		break;
>   	}
>



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