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

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

On 21/10/15 18:20, Ferger, Max wrote:
> Hi!

Hello,

> I'm sorry, but that didn't do the trick.
> Neither did trying, whether a compressed or non-compressed dom0 image would do.
> 
> Also, I tried:
> ----- 8< -----
> /chosen/xen,dom0-bootargs = "console=hvc0 earlyprintk=xen debug ignore_loglevel vmalloc=384M video=HDMI-A-1:1920x1080-32@60 ip=192.168.0.5:192.168.0.15:192.168.0.15:255.255.255.0:lager:eth0::: root=/dev/nfs rw nfsroot=192.168.0.15:/nfsroot rootdelay clk_ignore_unused";
> ----- 8< -----
> + earlyprintk=xen
> - rootwait
> + rootdelay
> 
> The log remains the same: empty from the switch to Dom0 onwards.
> 
> Many thanks so far!  Maybe there are some more investigative options to check or try out?

To be sure, even the patch I attached on the previous mail doesn't help
you to get the console?

If so, the simplest way to investigate requires the serial driver in Xen
to be functional (IIRC it's not the case right now). If you got it, you
can type CTRL-a tree times and access to the Xen console.

There is a number of key useful to dump the states of Xen and the
guests. The key '0' will dump the state of every vCPUs of DOM0. To list
the other keys available, type 'h'.

If getting the serial driver requires to much work, you will have to
modify DOM0 and add some xen_raw_printk (#include <xen/hvc-console.h>).
To figure out what's going on.

If you have Xen built with debug=y, from the log you sent it seems to be
the case, you can use the asm instruction "hvc" to get Xen printing
useful information:
    - hvc 0xffff will dump the state of the vCPU
    - hvc 0xfffd will print the program counter
For more of them see do_debug_trap in xen/arch/arm/traps.c

I hope this will help you to get further in DOM0 boot.

Regards,

-- 
Julien Grall