EFI from usb HDD

[AKASHI Takahiro]

On Fri, Jul 30, 2021 at 06:41:01AM +0200, Michal Simek wrote:
> 
> 
> 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.

OK, but we are already in grub here and such a trace (in U-Boot)
doesn't make sense. Right?

-Takahiro Akashi

> Thanks,
> Michal
>