Re: Dom0 kernel for Xen4.6 on R-Car H2 (LAGER)

[Julien Grall <julien.grall@citrix.com>]

Hi,

On 20/10/2015 09:48, Ferger, Max wrote:
> Many thanks for the attention, and the help so far!
>
> * There are still warnings about the console not being properly configured. This issue seems not urgent to me, also I would appreciate a fix.
>
> * Something goes wrong while booting Dom0.  Please help me in understanding why?
>
> * I still don't know too much about how to modify Dom0.  I just try to run a Poky I created with Renesas' help, which has been successfully running on the board without Xen.

> (XEN) Checking for initrd in /chosen
> (XEN) RAM: 0000000040000000 - 000000007fffffff
> (XEN) RAM: 0000000140000000 - 00000001ffffffff
> (XEN)
> (XEN) MODULE[0]: 00000000407f2000 - 00000000407fd000 Device Tree
> (XEN) MODULE[1]: 0000000072000000 - 00000000722fd158 Kernel
> (XEN) MODULE[2]: 0000000074000000 - 0000000074002559 XSM
> (XEN)  RESVD[0]: 0000000070f00000 - 0000000070f0b000
> (XEN)  RESVD[1]: 000000007ff9a000 - 000000007ff9a120
> (XEN)  RESVD[2]: 00000000407f2000 - 00000000407fd000
> (XEN)
> (XEN) Command line: console=dtuart dom0_mem=1G
> (XEN) Placing Xen at 0x000000007fc00000-0x000000007fe00000
> (XEN) Update BOOTMOD_XEN from 0000000090000000-000000009011b701 => 000000007fc00000-000000007fd1b701
> (XEN) Xen heap: 00000001f8000000-0000000200000000 (32768 pages)
> (XEN) Dom heap: 1015808 pages
> (XEN) Domain heap initialised
> (XEN) Platform: Renesas R-Car Gen2
> (XEN) Taking dtuart configuration from /chosen/stdout-path
> (XEN) Looking for dtuart at "/serial@e6c40000", options ""
> (XEN) Unable to initialize dtuart: -9

It looks like your platform is using an UART compatible with 
"renesas,scifa".

Although, for the moment, the driver in Xen is only supporting 
"renesas,scif".

Looking to the Linux drivers (drivers/tty/serial/sh-sci.c), there is few 
differences between the two UART, mostly about the register offsets.

Meanwhile, you can stay on the earlyprintk until you get DOM0 to boot. 
It only means that Xen won't be able to receive character and interact 
with you.

> (XEN) Bad console= option 'dtuart'
>   __  __            _  _    __    ___
>   \ \/ /___ _ __   | || |  / /_  / _ \
>    \  // _ \ '_ \  | || |_| '_ \| | | |
>    /  \  __/ | | | |__   _| (_) | |_| |
>   /_/\_\___|_| |_|    |_|(_)___(_)___/

[..]

> (XEN) handle /pci@ee090000/usb@0,1
> (XEN) /pci@ee090000/usb@0,1 passthrough = 1 nirq = 0 naddr = 0
> (XEN) Mapping children of /pci@ee090000/usb@0,1 to guest
> (XEN) DT: no ranges; cannot enumerate

Thank you for the log. The offending node is /pci@ee090000/usb@0,1 which 
is (r8a7790.dtsi):

1407                 usb@0,1 {
1408                         reg = <0x800 0 0 0 0>;
1409                         device_type = "pci";
1410                         phys = <&usb0 0>;
1411                         phy-names = "usb";
1412                 };
1413

We assume that every node containing device_type = "pci" is a PCI bus. 
So Xen is looking for a property "ranges" which is not present.

Although, here it's describing a PCI device. I wasn't able to find a 
spec telling that device_type = "pci"; should only be used by the PCI 
bus. Ian, do you remember why you implement with this assumption?

For now, I would advice you to drop this node, the next one (usb@0,2) 
and doing the same in "pci@ee0d0000". We can figure out later how to fix 
it when you get a DOM0 booting.

> (XEN) Device tree generation failed (-22).
> (XEN)
> (XEN) ****************************************
> (XEN) Panic on CPU 0:
> (XEN) Could not set up DOM0 guest OS
> (XEN) ****************************************
> (XEN)
> (XEN) Reboot in five seconds...

Regards,

-- 
Julien Grall