Also CC'ing Andre that I think has a pine64.

On Tue, 4 Apr 2017, Stefano Stabellini wrote:
> On Sat, 1 Apr 2017, bharat gohil wrote:
> > Hello
> 
> Hello Bharat, thanks for your email.
> 
> 
> > I am trying to boot xen(debug build) on pine64 ARM64 based board but its hangs at following position,
> > 
> > - UART enabled -
> > - CPU 00000000 booting -
> > - Current EL 00000008 -
> > - Xen starting at EL2 -
> > - Zero BSS -
> > - Setting up control registers -
> > - Turning on paging -
> > - Ready -
> > (XEN) Checking for initrd in /chosen
> > (XEN) RAM: 0000000041000000 - 000000007fffffff
> > (XEN)
> > (XEN) MODULE[0]: 000000007e200000 - 000000007e202000 Device Tree
> > (XEN) MODULE[1]: 000000007e400000 - 000000007ef46a00 Kernel       console=hvc0 ro root=/dev/mmcblk0p2 clk_ignore_unused rootwait
> > (XEN)  RESVD[0]: 000000007e200000 - 000000007e202000
> > (XEN)
> > (XEN) Command line: dtuart=serial0 earlyprint loglvl=all conswitch=x dom0_mem=128M
> > (XEN) Placing Xen at 0x000000007fc00000-0x000000007fe00000
> > (XEN) Update BOOTMOD_XEN from 000000007fe00000-000000007fefad81 => 000000007fc00000-000000007fcfad81
> > (XEN) Booting using Device Tree
> > (XEN) Domain heap initialised
> > (XEN) Platform: Generic System
> > (XEN) Looking for dtuart at "serial0", options ""
> >  Xen 4.9-unstable
> > (XEN) Xen version 4.9-unstable (bgohil@) (aarch64-linux-gnu-gcc (Linaro GCC 6.2-2016.11) 6.2.1 20161016) debug=n  Tue Mar 28 16:12:32 IST 2017
> > (XEN) Latest ChangeSet: Fri Mar 24 14:19:47 2017 +0100 git:5b08f85
> > (XEN) Processor: 410fd034: "ARM Limited", variant: 0x0, part 0xd03, rev 0x4
> > (XEN) 64-bit Execution:
> > (XEN)   Processor Features: 0000000000002222 0000000000000000
> > (XEN)     Exception Levels: EL3:64+32 EL2:64+32 EL1:64+32 EL0:64+32
> > (XEN)     Extensions: FloatingPoint AdvancedSIMD
> > (XEN)   Debug Features: 0000000010305106 0000000000000000
> > (XEN)   Auxiliary Features: 0000000000000000 0000000000000000
> > (XEN)   Memory Model Features: 0000000000001122 0000000000000000
> > (XEN)   ISA Features:  0000000000011120 0000000000000000
> > (XEN) 32-bit Execution:
> > (XEN)   Processor Features: 00000131:00011011
> > (XEN)     Instruction Sets: AArch32 A32 Thumb Thumb-2 Jazelle
> > (XEN)     Extensions: GenericTimer Security
> > (XEN)   Debug Features: 03010066
> > (XEN)   Auxiliary Features: 00000000
> > (XEN)   Memory Model Features: 10201105 40000000 01260000 02102211
> > (XEN)  ISA Features: 02101110 13112111 21232042 01112131 00011142 00011121
> > (XEN) Using PSCI-0.2 for SMP bringup
> > (XEN) SMP: Allowing 4 CPUs
> > (XEN) Generic Timer IRQ: phys=30 hyp=26 virt=27 Freq: 24000 KHz
> > (XEN) GICv2 initialization:
> > (XEN)         gic_dist_addr=0000000001c81000
> > (XEN)         gic_cpu_addr=0000000001c82000
> > (XEN)         gic_hyp_addr=0000000001c84000
> > (XEN)         gic_vcpu_addr=0000000001c86000
> > (XEN)         gic_maintenance_irq=25
> > (XEN) GICv2: 224 lines, 4 cpus, secure (IID 0200143b).
> > (XEN) Using scheduler: SMP Credit Scheduler (credit)
> > 
> > but when I boot dtuart=<unknown value> say duart=xyz instead of dtuart=serial0, xen booted successfully but Dom0 crash while probing 'serial0' driver. 
> > 
> > If I remove 'serial0' node from device tree, Dom0 boot successfully but unable to enter input into 'hvc' console. 
> > 
> > what could be wrong here or missing something?
> 
> What is your dom0 command line? Are you passing console=hvc0?
> 
> It looks like pine64 is using an allwinner sun50i-uart, for which we
> don't have a proper driver in Xen yet. That is probably the reason why
> you can see some output from Xen, but you cannot type anything in later
> in Dom0 (which is sent to Xen via the HVC console).  Please send a patch
> to add a simple sun50i-uart driver (see xen/drivers/char/). Given that
> both Xen and Linux are GPLv2, you can import code from Linux if you find
> it appropriate.
> 
> Cheers,
> 
> Stefano