EFI from usb HDD

Fri Jul 30 06:41:01 CEST 2021

On 7/30/21 4:35 AM, AKASHI Takahiro wrote:
> On Thu, Jul 29, 2021 at 04:09:32PM +0200, Michal Simek wrote:
>> Hi,
>>
>> On 6/10/21 2:59 PM, AKASHI Takahiro wrote:
>>> On Thu, Jun 10, 2021 at 02:31:46PM +0200, Michal Simek wrote:
>>>>
>>>>
>>>> On 6/10/21 12:51 PM, Heinrich Schuchardt wrote:
>>>>> 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?
>>>>
>>>> It is not just usb. SCSI/sata are behaving in the same way too.
>>>>
>>>>>
>>>>> 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.
>>>>
>>>> Right. And also there are commands which can create MBR partitions and I
>>>> expect when you write image to SD and then run rescan or so you could
>>>> get other partitions too.
>>>> Maybe hook via part_init()? with removing efi_disk_register.
>>>
>>> For the record, I have proposed my ideas several times[1], [2].
>>> I'm, however, no longer working on this issue as I have shifted
>>> my focus to UEFI secure boot and capsule update.
>>>
>>> -Takahiro Akashi
>>>
>>> [1] https://lists.denx.de/pipermail/u-boot/2018-November/347491.html
>>> [2] https://lists.denx.de/pipermail/u-boot/2019-February/357923.html
>>
>> I want to continue on this thread. I have disabled
>> EFI_CAPSULE_ON_DISK_EARLY some time ago and trying to workaround that
>> usb/scsi detection by simply calling usb reset and scsi reset as the
>> part of PREBOOT. Then all disks are recorded and visible by grub.
>>
>> But I found another issue which is kind of weird. We are using
>> distroboot with soft of fixed sequence. Important part of sequence is
>> sd, usb, scsi.
>>
>> I have added grub on scsi and when I boot directly via run bootcmd_scsi0
>> everything is working fine. When I let distroboot to do the job it or
>> run printenv -e before bootcmd_scsi0 I am getting exception.
>> From debug it is visible that it is exception called from
>> efi_disk_read_blocks.
>>
>>     0  0x7ff5d188 hang()+20: include/bootstage.h, line 389
>>     1  0x7ff5f908 __assert_fail(): lib/panic.c, line 25
>>     2  0x7fe976a8 do_irq(): arch/arm/lib/interrupts_64.c, line 123
>>     3  0x7fe96a0c _restore_regs()+124: arch/arm/cpu/armv8/exceptions.S,
>> line 141
>>     4  0x7ff43740 efi_disk_read_blocks()+160: lib/efi_loader/efi_disk.c,
>> line 102
> 
> How and when did you get this stack trace?

When Abort happened I connected Xilinx debugger via jtag and look at cpu
backtrace.

Thanks,
Michal