EFI from usb HDD

[Heinrich Schuchardt]

On 6/10/21 12:04 PM, Michal Simek wrote:
> Hi,
>
> On 6/10/21 11:47 AM, Heinrich Schuchardt wrote:
>> On 6/10/21 10:44 AM, Michal Simek wrote:
>>> Hi,
>>>
>>> I am playing with booting from USB via EFI. And I see very weird
>>> behavior. I have burnt image with grub to USB flashdisk and I have
>>> tested it on 3 zynqmp boards. zcu102, zcu104 and SOM Kria board.
>>> On zcu102 grub is going to boot menu and everything is working fine as
>>> expected.
>>> On zcu104 and SOM Kria I am able to get grub not to menu. When I list
>>> partitions in grub I see that only SDs are listed:
>>> grub> ls
>>> (hd0) (hd0,msdos1) (hd1) (hd1,msdos1)
>>
>> Hello Michal,
>>
>> thanks for sharing your observations.
>>
>> What devices do hd0 and hd1 relate to?
>>
>>>
>>> On zcu102(working board) I also see usb(gpt) partitions and SD.
>>> grub> ls
>>> (hd0) (hd0,gpt2) (hd0,gpt1) (hd1) (hd1,msdos1)
>>>
>>
>> GPT and MBR partitioning are independent of the device type.
>>
>>>
>>> On zcu104 I see one more error message
>>> "PE image measurement failed"
>>
>> This is related to CONFIG_EFI_TCG2_PROTOCOL=y. Do you have a TPMv2? This
>> will not stop disk enumeration.
>>
>>> But I can't see it on SOM.
>>>
>>> U-Boot image is just the same for all boards. I am using generic
>>> xilinx_zynqmp_virt_defconfig.
>>>
>>> When I compare DT description for USB between zcu102 and zcu104 they are
>>> the same. SOM doesn't have usb enabled by default (but I enabled it) but
>>> grub starts which means that communication with USB is fine.
>>>
>>> It is based on my latest patches available here.
>>> u-boot/custodians/u-boot-microblaze.git (usb-efi-issue branch)
>>>
>>> Also when I list usb I see all partitions just fine.
>>> ZynqMP> part list usb 0
>>>
>>> Partition Map for USB device 0  --   Partition Type: EFI
>>>
>>> Part    Start LBA       End LBA         Name
>>>           Attributes
>>>           Type GUID
>>>           Partition GUID
>>>     1     0x00000800      0x001007fe      "Microsoft basic data"
>>>           attrs:  0x0000000000000000
>>>           type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
>>>           type:   data
>>>           guid:   0e7f8b3d-296b-4720-be9d-c4687d3c4a77
>>>     2     0x00100800      0x001197fe      "Microsoft basic data"
>>>           attrs:  0x0000000000000000
>>>           type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
>>>           type:   data
>>>           guid:   8892eddc-231a-4e6e-a5e1-c310f4482fb7
>>>
>>>
>>> Do you have any idea why on one system is working fine to get to menu
>>> and on others there is an issue to get all partitions even u-boot is
>>> able to see them and can work with them.
>>>
>>> Thanks,
>>> Michal
>>>
>>
>> Where is the GRUB binary? - If it is in EFI/boot/bootaa64.efi, it could
>> be that the USB sub-system is simply not initialized yet when the boot
>> manager is called by distroboot.
>>
>> For testing partition detection in the UEFI sub-system it is enough to run
>>
>>      efidebug devices
>>
>> Until yesterday we had a problem with partition numbers >= 10, cf.
>>
>> efi_loader: partition numbers are hexadecimal
>> https://source.denx.de/u-boot/u-boot/-/commit/3dca77b1dc1b6dbf9c8b51572fe4b0553cef009f
>>
>>
>> Block devices are enumerated in efi_disk_register(). Please, try to add
>> debug output there to elucidate the problem.
>
> I found where the problem is. First of all zcu102 didn't use the same
> image as others (it wasn't updated properly).
> When you have CONFIG_EFI_CAPSULE_ON_DISK_EARLY that efi_disk_register()
> is called before usb block devices are detected and registered that's
> why grub doesn't see them.

The problem is CONFIG_EFI_SETUP_EARLY=y required by
CONFIG_EFI_CAPSULE_ON_DISK_EARLY.

Why is USB initialized later then MMC?

Overall we have a deficiency in the UEFI implementation in that we
cannot deal with block devices added or removed after initialization.

Here integration with the driver model is missing.

> I was looking at adding usb start in preboot but preboot is called later.
> How this should be solved? Any idea?
>
> Thanks,
> Michal
>
>
+cc Sughosh, Takahiro (who have developed the capsule code)

Best regards

Heinrich