sbruno@tasty.ysv:~ % qemu-system-mips64 -m 512M -M malta -kernel /var/tmp/mips.mips64/home/sbruno/mips64-clang/sys/MALTA64/kernel.full -hda ./mips64_clang.img -nographic
WARNING: Image format was not specified for './mips64_clang.img' and probing guessed raw.
         Automatically detecting the format is dangerous for raw images, write operations on block 0 will be restricted.
         Specify the 'raw' format explicitly to remove the restrictions.
entry: platform_start()
cmd line: /var/tmp/mips.mips64/home/sbruno/mips64-clang/sys/MALTA64/kernel.full  
envp:
        memsize = 268435456
        ememsize = 536870912
        modetty0 = 38400n8r
memsize = 268435456 (0x10000000)
ememsize = 536870912
Cache info:
  icache is virtual
  picache_stride    = 8192
  picache_loopcount = 4
  pdcache_stride    = 4096
  pdcache_loopcount = 8
cpu0: MIPS Technologies processor v160.130
  MMU: Standard TLB, 48 entries (4K 16K 64K 256K 1M 16M 64M 256M pg sizes)
  L1 i-cache: 4 ways of 256 sets, 32 bytes per line
  L1 d-cache: 4 ways of 256 sets, 32 bytes per line
  L2 cache: disabled
  Config1=0xdea3519b<PerfCount,WatchRegs,EJTAG,FPU>
  Config2=0x80000000
Physical memory chunk(s):
0x71e000 - 0xfffffff, 260972544 bytes (63714 pages)
0x90000000 - 0x9fffffff, 268435456 bytes (65536 pages)
Maxmem is 0xa0000000
KDB: debugger backends: ddb
KDB: current backend: ddb
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FreeBSD 12.0-CURRENT #2 r304849M: Fri Aug 26 16:42:27 UTC 2016
    sbruno@tasty.ysv.freebsd.org:/var/tmp/mips.mips64/home/sbruno/mips64-clang/sys/MALTA64 mips
clang version 4.0.0 (trunk 279820)
Preloaded elf kernel "kernel" at 0xffffffff80711d70.
real memory  = 536870912 (524288K bytes)
Physical memory chunk(s):
0x0083b000 - 0x0fffffff, 259805184 bytes (63429 pages)
0x90000000 - 0x9f2e0fff, 254676992 bytes (62177 pages)
avail memory = 511922176 (488MB)
Trap cause = 4 (address error (load or I-fetch) - kernel mode)
[ thread pid 0 tid 100000 ]
Stopped at      vm_object_allocate+0x68:        ld      at,-3200(at)
db> bt
Tracing pid 0 tid 100000 td 0xffffffff80719fd0
db_trace_thread+80 (?,?,?,?) ra ffffffff80162af0 sp 9800000000737130 sz 416
ffffffff80162968+188 (?,?,?,?) ra ffffffff80162488 sp 98000000007372d0 sz 64
ffffffff80162100+388 (?,?,?,?) ra ffffffff801620c4 sp 9800000000737310 sz 224
db_command_loop+dc (?,?,?,?) ra ffffffff80167804 sp 98000000007373f0 sz 48
ffffffff80167648+1bc (?,?,?,?) ra ffffffff803713ec sp 9800000000737420 sz 816
kdb_trap+1cc (?,?,?,?) ra ffffffff805962ec sp 9800000000737750 sz 80
ffffffff805961ac+140 (?,?,?,?) ra 0 sp 98000000007377a0 sz 0
pid 0
db>