== DF-2376(b) choreography, console narration (ACHARNESS #3) ==
ACSIM-NOTE: DF-2376(b): blocker; NB2; free battery:2 softc; deferred get_bif_task -> device_get_softc==NULL -> expect trap
ACSIM-NOTE: DF-2376(b): softc freed; blocker out at 30s; task reads sc->bix_present via NULL softc
(30s later, on the acpi_task helper thread:)
Fatal trap 12: page fault while in kernel mode
cpuid = 0; lapic id = 0
fault virtual address	= 0xc
current process		= Idle
kernel: type 12 trap, code=0
Stopped at      acpi_cmbat_get_bif+0xaa:        movl    0xc(%r13),%r8d