BBB translation fault panic with "kldload"

[Keith White]

I get a kernel panic when trying to use kernel modules with recent
BBB kernels.

Here's what happens when I try to "kldload nullfs" with a freshly
built r276468:

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Wed Dec 31 08:29:28 EST 2014

FreeBSD/arm (beaglebone) (ttyu0)

login: root
Password:
Dec 31 08:30:28 beaglebone login: ROOT LOGIN (root) ON ttyu0
FreeBSD 11.0-CURRENT (BEAGLEBONE) #0 r276468M: Wed Dec 31 08:22:23 EST 2014
root at beaglebone:~ # uname -ap
FreeBSD beaglebone 11.0-CURRENT FreeBSD 11.0-CURRENT #0 r276468M: Wed Dec 31 08:22:23 EST 2014     kwhite at freebsd11:/usr/obj/arm.armv6hf/tank/RPI/head/sys/BEAGLEBONE  arm armv6hf
root at beaglebone:~ # kldload nullfs

vm_fault(0xc2e52000, 0, 1, 0) -> 1
Fatal kernel mode data abort: 'Translation Fault (P)'
trapframe: 0xde5daa50
FSR=00000017, FAR=00000000, spsr=60000113
r0 =00000000, r1 =0000b880, r2 =c2d96970, r3 =00000000
r4 =0000bb40, r5 =c2d9694c, r6 =c2d96978, r7 =00000032
r8 =c06f1084, r9 =c06e6d78, r10=c2aefe00, r11=de5daaa8
r12=00000001, ssp=de5daaa0, slr=c040c174, pc =c2d8c594

[ thread pid 642 tid 100079 ]
Stopped at      nullfs_init+0x20:       ldr     r0, [r0]
db> show reg
spsr        0x60000113
r0                   0
r1              0xb880
r2          0xc2d96970  $d+0xa0
r3                   0
r4              0xbb40
r5          0xc2d9694c  $d+0x7c
r6          0xc2d96978  $d+0xa8
r7                0x32
r8          0xc06f1084  vfsconf
r9          0xc06e6d78  _MergedGlobals+0xf8
r10         0xc2aefe00
r11         0xde5daaa8
r12                0x1
usr_sp      0xbffff058
usr_lr      0x20198fd8
svc_sp      0xde5daaa0
svc_lr      0xc040c174  vfs_modevent+0x43c
pc          0xc2d8c594  nullfs_init+0x20
und_sp      0xc0875000
abt_sp      0xc0874000
irq_sp      0xc0873000
nullfs_init+0x20:       ldr     r0, [r0]
db>

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...keith