Re: Xen Booting Problem on ARM Machine

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

Yes there are other ways but without serial is going to be difficult
because you are not going to see anything until everything works.

How do you boot Xen and Dom0 exactly from EDK2? Are you using GRUB or
loading Xen directly from the EDK2 prompt? Please provide as many
details as possible so that I might be able to spot any errors.

Can you provide the Device Tree you are using? If you are not passing
any Device Tree  binary explicitely, then it might be passed
automatically from EDK2 to Linux/Xen. In that case, just boot from Linux
then do the following to retrieve the Device Tree:

dtc -I fs -O dts /proc/device-tree > host.dts

Then please attach host.dts to this email thread.


Also for your information it looks like Linux actually booted from ACPI,
not from Device Tree, as you can see from all the "ACPI" messages in the
kernel logs.

If you need to boot from ACPI, then you need to enable ACPI support in
Xen, which is disabled by default. You can do that using make
menuconfig.


On Thu, 30 Sep 2021, Sai Kiran Kumar Reddy Y wrote:
> Hi,
> Sorry about the delay. We have been trying to access the serial of the 
> machine. Tried with couple of JTAG connectors. There's still no
> debug messages on the serial. Is there any other way of figuring this out?
> 
> On Wed, Sep 15, 2021, 7:02 AM Stefano Stabellini <sstabellini@xxxxxxxxxx> 
> wrote:
>       Something is off. When you enabled earlyprintk in Xen, you should see
>       something like this at boot time:
>       https://marc.info/?l=xen-devel&m=158829968025334
> 
>       All the Xen logs starting with "(XEN)" on the serial. Do you have access
>       to the serial of the machine? Without it, it is going to be hard to
>       debug.
> 
> 
>       On Tue, 14 Sep 2021, Sai Kiran Kumar Reddy Y wrote:
>       > In the folder "/var/log", there's a file called "xen", which is 
> empty. As far as the boot logs are concerned, I don't see any
>       debug
>       > messages related to xen. I am attaching the log files, "kern.txt" and 
> "boot.txt"
>       >
>       > On Tue, Sep 14, 2021 at 3:08 AM Stefano Stabellini 
> <sstabellini@xxxxxxxxxx> wrote:
>       >       On Mon, 13 Sep 2021, Sai Kiran Kumar Reddy Y wrote:
>       >       > On Fri, Sep 10, 2021 at 7:30 PM Julien Grall <julien@xxxxxxx> 
> wrote:
>       >       >
>       >       >
>       >       >       On 08/09/2021 11:43, Sai Kiran wrote:
>       >       >       > Hello,
>       >       >
>       >       >       Hi,
>       >       >
>       >       >       Thank you for the report. Moving the discussion back to 
> xen-devel
>       >       >       because this looks like a potential issue in the UEFI 
> stub in Xen.
>       >       >
>       >       >       > I have Xen-4.15.0 on an ARM Machine, with Debian 11 
> installed on it.
>       >       >
>       >       >       Would you be able to give more details on the Arm 
> machine you are using?
>       >       >       Also, are you using ACPI or DT to boot?
>       >       >
>       >       >
>       >       >    Sai >> DT . ACPI configuration is disabled in Boot 
> settings    
>       >       >
>       >       >       >  I
>       >       >       > am able to do “make world” and “make install”, after 
> “./configure”, as
>       >       >       > specified in README file. When I reboot the system, I 
> get the following
>       >       >       > message:
>       >       >       >
>       >       >       > Warning: All 128 bootinfo mem banks exhausted.
>       >       >       >
>       >       >       > Warning: All 128 bootinfo mem banks exhausted.
>       >       >
>       >       >       Hmmm... This means that you have more than 128 memory 
> regions described
>       >       >       in the EFI memory map. That's quite a lot.
>       >       >
>       >       >       Although, this should be harmless as it means Xen will 
> not use the extra
>       >       >       memory banks.
>       >       >
>       >       >       >
>       >       >       > Cannot exit boot services: ErrCode: 0x8000000000000002
>       >       >
>       >       >       This means EFI_INVALID_PARAMETER. We have code to retry 
> because AFAICT
>       >       >       ExitBootServices() may sometime fails (I have CCed Jan 
> may have more
>       >       >       idea what's happening).
>       >       >
>       >       >       Would you be able to provide more details on the UEFI 
> firmware you are
>       >       >       using? Is it EDK2 or U-boot?
>       >       >
>       >       > Sai >>  EDK2 
>       >       >       Also, do you know if Linux is boot on the same system?
>       >       >
>       >       > Sai >> Yes 
>       >       >       However, AFAICT, the error message would not prevent 
> Xen to continue
>       >       >       booting. So you may get stuck later in the boot process.
>       >       >
>       >       >       My suggestion would be to enable earlyprintk for your 
> platform. You can
>       >       >       setup it up from the menuconfig in "Debugging Options".
>       >       >
>       >       > Sai >> Yes, I have enabled earlyprintk.
>       >       > I tried changing NR_MEM_BANKS(in xen/include/asm-arm/setup.h) 
> value to 256, from 128. The error message is no longer
>       seen,
>       >       but the device
>       >       > is stuck in the boot process.
>       >
>       >       Could you please post the boot logs now that you enabled 
> earlyprintk?
>       >       Ideally not a camera picture but a textual copy/paste from the 
> target
>       >       serial?
>       >
>       >       Earlyprintk is pretty verbose, we should be able to figure out 
> where it
>       >       gets stuck.
>       >
>       >
>       >
> 
> 
>