BISECTED f3866909e350 ("distro_bootcmd: call EFI bootmgr even without having /EFI/boot")

[Heinrich Schuchardt]

On 6/6/21 5:42 PM, Matwey V. Kornilov wrote:
> вс, 6 июн. 2021 г. в 18:20, Heinrich Schuchardt <xypron.glpk at gmx.de>:
>>
>> On 6/6/21 4:37 PM, Matwey V. Kornilov wrote:
>>> Hi,
>>>
>>> I've found that
>>>
>>> f3866909e350 ("distro_bootcmd: call EFI bootmgr even without having /EFI/boot")
>>>
>>> breaks running EFI application from USB device on BeagleBone Black
>>> (am335x) device.
>>>
>>> With this patch I see the following:
>>>
>>> Booting /efi\boot\bootarm.efi
>>> Welcome to GRUB!
>>>
>>> data abort
>>> pc : [<9ce0b6d0>]          lr : [<9ffab7c7>]
>>> reloc pc : [<7d69d6d0>]    lr : [<8083d7c7>]
>>> sp : 9df44e28  ip : 9ffdfe90     fp : 00000003
>>> r10: 9ffe3300  r9 : 00000000     r8 : 9df6fe88
>>> r7 : 00000000  r6 : 9ce5da08     r5 : 9ce571f8  r4 : 9ce2c040
>>> r3 : 00000000  r2 : 00000001     r1 : 9ce56598  r0 : 00000000
>>> Flags: NzCv  IRQs off  FIQs on  Mode SVC_32
>>> Code: e3500000 0a000015 e590000c eb00f96e (e5d03000)
>>   > UEFI image [0x9ce46000:0x9cf28fff] '/efi\boot\bootarm.efi'
>>   > Resetting CPU ...
>>
>> Hello Matwey,
>>
>> thank you for reporting the issue.
>>
>> $ echo 'Code: e3500000 0a000015 e590000c eb00f96e (e5d03000)' |
>> CROSS_COMPILE=arm-linux-gnueabihf- ARCH=arm scripts/decodecode
>>
>> Code: e3500000 0a000015 e590000c eb00f96e (e5d03000)
>> All code
>> ========
>>      0:   e3500000        cmp     r0, #0
>>      4:   0a000015        beq     0x60
>>      8:   e590000c        ldr     r0, [r0, #12]
>>      c:   eb00f96e        bl      0x3e5cc
>>     10:*  e5d03000        ldrb    r3, [r0]                <-- trapping
>> instruction
>>
>> Code starting with the faulting instruction
>> ===========================================
>>      0:   e5d03000        ldrb    r3, [r0]
>>
>> Looking at the disassembly above we see that reading memory location
>> NULL fails.
>>
>> We need to find out where the exception occurs. The code position is
>> neither in bootarm.efi nor in U-Boot (9ce0b6d0 is lower than the load
>> position of bootarm.efi, so it is below the relocated U-Boot code).
>>
>> Please, add the following line at the start of grub.cfg to get more
>> output from GRUB:
>>
>>          debug=all
>
> This doesn't provide any additional output from GRUB :(
>
>>
>> When building U-Boot, please, add
>>
>>          #define DEBUG 1
>>
>> in lib/efi_loader/efi_disk.c and lib/efi_loader_file.c a line before
>> #include <common.h>.
>
>
> This doesn't provide much output as well:
>
> Scanning disk mmc at 48060000.blk...
> EFI: Call: efi_install_multiple_protocol_interfaces( &handle,
> &efi_guid_device_path, diskobj->dp, &efi_block_io_guid, &diskobj->ops,
> NULL)
> EFI: 0 returned by efi_install_multiple_protocol_interfaces( &handle,
> &efi_guid_device_path, diskobj->dp, &efi_block_io_guid, &diskobj->ops,
> NULL)
> ** Unrecognized filesystem type **
> Scanning disk mmc at 481d8000.blk...
> EFI: Call: efi_install_multiple_protocol_interfaces( &handle,
> &efi_guid_device_path, diskobj->dp, &efi_block_io_guid, &diskobj->ops,
> NULL)
> EFI: 0 returned by efi_install_multiple_protocol_interfaces( &handle,
> &efi_guid_device_path, diskobj->dp, &efi_block_io_guid, &diskobj->ops,
> NULL)
> EFI: Call: efi_install_multiple_protocol_interfaces( &handle,
> &efi_guid_device_path, diskobj->dp, &efi_block_io_guid, &diskobj->ops,
> NULL)
> EFI: 0 returned by efi_install_multiple_protocol_interfaces( &handle,
> &efi_guid_device_path, diskobj->dp, &efi_block_io_guid, &diskobj->ops,
> NULL)
> Found 3 disks

This implies that GRUB is crashing before even accessing the file system
(including grub.cfg).

On an OrangePi PC I deleted /boot.scr and moved grubarm.efi to
/EFI/boot/bootarm.efi. It boots without problem.

What version of GRUB are you using?
How were you booting before updating U-Boot?
What version of U-Boot are you using where the error occurs?
Why do you have grub in /EFI/boot/bootarm.efi and not in a distro
specific path, e.g. /EFI/debian/grubarm.efi? /EFI/boot is typically only
used by installers.

If the boot manager is started by distroboot it may not have an
appropriate device path. It tries to load the file given by environment
variable $fdtfile from the boot device.

 From the U-Boot console could you, please, try:

1)
load usb 0:1 $kernel_addr_r EFI/boot/bootarm.efi
bootefi bootmgr


2)
load usb 0:1 $kernel_addr_r EFI/boot/bootarm.efi
load usb 0:2 $fdt_addr_r dtb
bootefi bootmgr $fdt_addr_r

where you need to replace dtb by the correct device tree file and adjust
the partition numbers.

Best regards

Heinrich