Re: [Xen-devel] Problems running Xen 4.4 on OMAP5432 evm

["Kapania, Ashish" <akapania@xxxxxx>]

Hi Ian,

I was able to make progress with Xen 4.4 release itself. The xen image was being
placed at VA 0x200000 (which is not a valid address on OMAP5) so I had updated
xen.lds to change this. It seems that was the wrong thing to do and was causing
the problem (Does xen perform a VA to PA mapping for xen address space ?). After
undoing my changes, I was able to get further.

My latest xen log is shared below. Xen gets to the point where it says loading
Kernel but it does not look like dom0 linux is booting up as I donât see any
logs printed on uart. I have set "console=hvc0" in the dom0
Bootargs. I am running linux 3.8.13 and am able to boot it by itself so the
Linux image is working.

I am hoping to get some suggestions from you on how to debug this further.

Thanks,
Ashish

==============================================================================

FDT /chosen node:
U-Boot# fdt print /chosen
chosen {
        #size-cells = <0x00000001>;
        #address-cells = <0x00000001>;
        xen,xen-bootargs = "dom0_mem=128M sync_console console=dtuart 
dtuart=serial2 noreboot ";
        xen,dom0-bootargs = "console=hvc0 root=/dev/mmcblk0p2 rw rootwait 
fixrtc";
        module@0 {
                reg = <0x80300000 0x00500000>;
                compatible = "xen,linux-zimage", "xen,multiboot-module";
        };
};
==============================================================================

XEN Log:
U-Boot# fatload mmc 0 0x825f0000 omap5-uevm.dtb
reading omap5-uevm.dtb
27990 bytes read in 8 ms (3.3 MiB/s)
U-Boot# fatload mmc 0 0x80300000 zImage
reading zImage
5039880 bytes read in 270 ms (17.8 MiB/s)
U-Boot# fatload mmc 0 0xE0000000 uXen
reading uXen
656208 bytes read in 37 ms (16.9 MiB/s)
...
U-Boot# bootm 0xE0000000 - 0x825F0000
## Booting kernel from Legacy Image at e0000000 ...
   Image Name:   Xen
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    656144 Bytes = 640.8 KiB
   Load Address: 85000000
   Entry Point:  85000000
   Verifying Checksum ... OK
## Flattened Device Tree blob at 825f0000
   Booting using the fdt blob at 0x825f0000
   Loading Kernel Image ... OK
   reserving fdt memory region: addr=825f0000 size=7000
   Loading Device Tree to 83ff6000, end 83ffffff ... OK

Starting kernel ...

- UART enabled -
- CPU 00000000 booting -
- Xen starting in Hyp mode -
- Zero BSS -
- Setting up control registers -
- Turning on paging -
- Ready -
Checking for initrd in /chosen
RAM: 0000000080000000 - 00000000feffffff

MODULE[1]: 0000000083ff6000 - 0000000083ffd000 
MODULE[2]: 0000000080300000 - 0000000080800000 
 RESVD[0]: 00000000825f0000 - 00000000825f7000
 RESVD[1]: 0000000083ff6000 - 0000000083ffd000

Command line: dom0_mem=128M sync_console console=dtuart dtuart=serial2 noreboot
Placing Xen at 0x00000000fee00000-0x00000000ff000000
Xen heap: 00000000ee000000-00000000fe000000 (65536 pages)
Dom heap: 454656 pages
Looking for UART console serial2
 Xen 4.4.0
(XEN) Xen version 4.4.0 (a0273866@) (arm-linux-gnueabihf-gcc (crosstool-NG 
linaro-1.13.1-4.7-2013.03-20130313 - Linaro GCC 2013.03) 4.7.3 20130226 
(prerelease)) debug=y Mon Apr 21 17:29:21 PDT 2014
(XEN) Latest ChangeSet: Mon Mar 10 10:23:39 2014 +0000 git:816e8d8-dirty
(XEN) Console output is synchronous.
(XEN) Processor: 412fc0f2: "ARM Limited", variant: 0x2, part 0xc0f, rev 0x2
(XEN) 32-bit Execution:
(XEN)   Processor Features: 00001131:00011011
(XEN)     Instruction Sets: AArch32 Thumb Thumb-2 ThumbEE Jazelle
(XEN)     Extensions: GenericTimer Security
(XEN)   Debug Features: 02010555
(XEN)   Auxiliary Features: 00000000
(XEN)   Memory Model Features: 10201105 20000000 01240000 02102211
(XEN)  ISA Features: 02101110 13112111 21232041 11112131 10011142 00000000
(XEN) Platform: TI OMAP5
(XEN) Set AuxCoreBoot1 to 00000000fee0004c (0020004c)
(XEN) Set AuxCoreBoot0 to 0x20
(XEN) DT missing boot CPU MPIDR[23:0]
(XEN) Using only 1 CPU
(XEN) Generic Timer IRQ: phys=30 hyp=26 virt=27
(XEN) Using generic timer at 6144 KHz
(XEN) GIC initialization:
(XEN)         gic_dist_addr=0000000048211000
(XEN)         gic_cpu_addr=0000000048212000
(XEN)         gic_hyp_addr=0000000048214000
(XEN)         gic_vcpu_addr=0000000048216000
(XEN)         gic_maintenance_irq=25
(XEN) GIC: 192 lines, 2 cpus, secure (IID 0000043b).
(XEN) Using scheduler: SMP Credit Scheduler (credit)
(XEN) Allocated console ring of 16 KiB.
(XEN) VFP implementer 0x41 architecture 4 part 0x30 variant 0xf rev 0x0
(XEN) Brought up 1 CPUs
(XEN) *** LOADING DOMAIN 0 ***
(XEN) Populate P2M 0x88000000->0x90000000 (1:1 mapping for dom0)
(XEN) Loading kernel from boot module 2
(XEN) Loading zImage from 0000000080300000 to 000000008fa00000-000000008fece708
(XEN) Loading dom0 DTB to 0x000000008f800000-0x000000008f806d67
(XEN) Scrubbing Free RAM: .................done.
(XEN) Initial low memory virq threshold set at 0x4000 pages.
(XEN) Std. Loglevel: All
(XEN) Guest Loglevel: All
(XEN) **********************************************
(XEN) ******* WARNING: CONSOLE OUTPUT IS SYNCHRONOUS
(XEN) ******* This option is intended to aid debugging of Xen by ensuring
(XEN) ******* that all output is synchronously delivered on the serial line.
(XEN) ******* However it can introduce SIGNIFICANT latencies and affect
(XEN) ******* timekeeping. It is NOT recommended for production use!
(XEN) **********************************************
(XEN) 3... 2... 1... 
(XEN) *** Serial input -> DOM0 (type 'CTRL-a' three times to switch input to 
Xen)
(XEN) Freed 264kB init memory.

-----Original Message-----
From: Kapania, Ashish 
Sent: Wednesday, April 16, 2014 11:22 AM
To: 'Ian Campbell'
Cc: xen-devel@xxxxxxxxxxxxx
Subject: RE: [Xen-devel] Problems running Xen 4.4 on OMAP5432 evm

Hi Ian, Julien,

Thanks for your response.

I set "debug=y" to make earlyprintk work.

I added a few earlyprintk stmts in setup_pagetable() to narrow down the 
problem. The last print msg I get is just before flush_xen_text_tlb(). I donât 
get the prints after that call.

After the above exercise, I decided to check if the A15's mode somehow got 
changed from Hypervisor Mode to some other mode.
I read the CPSR using inline assembly and passed it to the printk call just 
before flush_xen_text_tlb(). I found that the print message is no longer 
printed when I added the CPSR argument.
So, if I try to add an argument to printk before tlb flush, the message is not 
printed but if I remove the argument it gets printed. It does not look like the 
prints are being buffered so I am a bit confused by this behavior.

0xfee000000 address should be in RAM. The RAM address range is 0x80000000 to 
0xFFFFFFFF.

I will try building using the development branch to see if that helps.

Best,
Ashish

-----Original Message-----
From: Ian Campbell [mailto:Ian.Campbell@xxxxxxxxxx]
Sent: Wednesday, April 16, 2014 3:43 AM
To: Kapania, Ashish
Cc: xen-devel@xxxxxxxxxxxxx
Subject: Re: [Xen-devel] Problems running Xen 4.4 on OMAP5432 evm

On Wed, 2014-04-16 at 00:23 +0000, Kapania, Ashish wrote:
> Hi,
> 
> I am trying to run Xen (+ Linux dom0) on OMAP5432 evm and have been 
> having trouble just booting xen itself. The xen wiki does not have 
> build instructions for OMAP5432 but the source code seems to have 
> support for it so I am assuming that board is supported. I am using 
> xen RELEASE-4.4.0 git tag to build a xen image. Here's my build command-line:
> 
> make dist-xen XEN_TARGET_ARCH=arm32 CROSS_COMPILE=arm-linux-gnueabihf-
> CONFIG_EARLY_PRINTK=omap5432

Worth trying with "debug=y" on this too (will need a complete clean to take 
full affect)

> When I boot xen, I see the A15 hangs in setup_pagetables() function in 
> arch/arm/mm.c file.

Can you say exactly where?

> MODULE[1]: 0000000083ff6000 - 0000000083ffd000
>  RESVD[0]: 00000000825f0000 - 00000000825f7000
>  RESVD[1]: 0000000083ff6000 - 0000000083ffd000
> 
> Command line: dom0_mem=256M console=dtuart dtuart=serial2 
> earlyprintk=xen Placing Xen at 0x00000000fee00000-0x00000000ff000000

At this point Xen will be relocating itself. I'm not sure what has gone wrong 
though. I presume 0xfee000000 is actually in RAM?

> Any ideas on what I might be doing wrong ? Maybe I am missing some 
> patch that is required to run xen on omap5432 ?

I can't think of any relevant patches which aren't in 4.4.0, but it would 
certainly be good to try the development branch to be sure (if that works then 
we can figure out which patch needs backporting).

Otherwise I'm afraid the issue will need some more debugging.

Ian.

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