Running Linux 3.14 as a Genode VM

[Nico Weichbrodt]

Hi,

I'm a student at TU Braunschweig and I inherited a Genode project from another student.
He used Genode on an i.MX53 Quick Start Board to boot a Linux 2.6.35 kernel (this one: https://github.com/skalk/linux) as a VM with TrustZone support. This works fine.

For my task I need a newer kernel, so I'm currently trying to upgrade to kernel 3.14. Since this kernel requires dtbs I modified Genode to load the dtb instead of ATAGs. I had to modify my dtb so the memory layout matches and to set the bootargs. My kernel now boots but hangs very soon at this point:

Uncompressing Linux... done, booting the kernel.
[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Initializing cgroup subsys cpu
[    0.000000] Initializing cgroup subsys cpuacct
[    0.000000] Linux version 3.14.15-00329-gaed2dee-dirty (envy at ...289.....) (gcc version 4.5.2 (Sourcery G++ Lite 2011.03-41) ) #40 Wed Jan 14 16:06:19 CET 2015
[    0.000000] CPU: ARMv7 Processor [412fc085] revision 5 (ARMv7), cr=10c5387d
[    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[    0.000000] Machine model: Freescale i.MX53 Quick Start-R Board
[    0.000000] bootconsole [earlycon0] enabled
[    0.000000] Memory policy: Data cache writeback
[    0.000000] On node 0 totalpages: 131072
[    0.000000] free_area_init_node: node 0, pgdat c05b36e8, node_mem_map dfbf9000
[    0.000000]   Normal zone: 1024 pages used for memmap
[    0.000000]   Normal zone: 0 pages reserved
[    0.000000]   Normal zone: 131072 pages, LIFO batch:31
[    0.000000] CPU: All CPU(s) started in SVC mode.
[    0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
[    0.000000] pcpu-alloc: [0] 0 
[    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 130048
[    0.000000] Kernel command line: console=ttymxc0,115200 earlyprintk loglevel=10
[    0.000000] PID hash table entries: 2048 (order: 1, 8192 bytes)
[    0.000000] Dentry cache hash table entries: 65536 (order: 6, 262144 bytes)
[    0.000000] Inode-cache hash table entries: 32768 (order: 5, 131072 bytes)
[    0.000000] Memory: 513696K/524288K available (4039K kernel code, 219K rwdata, 1384K rodata, 198K init, 123K bss, 10592K reserved, 0K highmem)
[    0.000000] Virtual kernel memory layout:
[    0.000000]     vector  : 0xffff0000 - 0xffff1000   (   4 kB)
[    0.000000]     fixmap  : 0xfff00000 - 0xfffe0000   ( 896 kB)
[    0.000000]     vmalloc : 0xe0800000 - 0xff000000   ( 488 MB)
[    0.000000]     lowmem  : 0xc0000000 - 0xe0000000   ( 512 MB)
[    0.000000]     pkmap   : 0xbfe00000 - 0xc0000000   (   2 MB)
[    0.000000]     modules : 0xbf000000 - 0xbfe00000   (  14 MB)
[    0.000000]       .text : 0xc0008000 - 0xc0553f8c   (5424 kB)
[    0.000000]       .init : 0xc0554000 - 0xc0585bbc   ( 199 kB)
[    0.000000]       .data : 0xc0586000 - 0xc05bcda0   ( 220 kB)
[    0.000000]        .bss : 0xc05bcda0 - 0xc05dba2c   ( 124 kB)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] NR_IRQS:16 nr_irqs:16 16
[    0.000000] TrustZone Interrupt Controller (TZIC) initialized
[    0.000000] CPU identified as i.MX53, silicon rev 2.1
[    0.000000] Switching to timer-based delay loop
[    0.000009] sched_clock: 32 bits at 33MHz, resolution 29ns, wraps every 128849015778ns
[    0.008364] Console: colour dummy device 80x30
[    0.012925] Calibrating delay loop (skipped), value calculated using timer frequency.. 

If I add some debug statements to linux/init/calibrate.c before the pr_info("Calibrating delay loop (skipped) ..."); then those get printed as well, but the "Calibrating..." text is not. I also added a loop at the top of the calibrate_delay() function which just prints an incrementing counter but this loop only prints once and then hangs.

Now I have two assumptions: Either the serial driver is hanging or it has something to do with the clocks/timer because the highest time passed number I got was 0.016800-ish.

I have not yet replayed the TrustZone commits from Stefan Kalkowski for Linux 2.6.35 but because I set all devices as unsecure inside Genode (genode/repos/base-hw/src/core/include/spec/imx53/trustzone/csu.h) this should not be necessary, right?

If you have any pointers/ideas/suggestions for me, this would be very helpful.

Cheers,
Nico Weichbrodt