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35 .Nd ACPI NVDIMM driver
37 To load the driver as a module at boot, place the following line in
39 .Bd -literal -offset indent
47 driver is under development and has some important limitations
53 driver provides access to Non-Volatile DIMM (NVDIMM) persistent memory
54 devices, which are ACPI-enumerated under the root NVDIMM device
63 For each System Physical Address (SPA) Range described by NFIT, a
65 .Pa /dev/nvdimm_spaNNN
68 is the SPA position in the table.
69 The node can be used to
76 Also, for each SPA, the geom provider
78 is created, which can be used to create a conventional filesystem (e.g.,
83 it as any storage volume.
85 .Pa /dev/nvdimm_spaNNN
92 driver has support for reading NVDIMM namespaces (if supported by your
93 hardware and already configured by some other mechanism, e.g., a BIOS
94 configuration screen).
95 The driver will provide a
96 .Pa /dev/nvdimm_spaNNNnsMMM
99 geom provider for each namespace in a SPA, which behave analogously to their
100 full-SPA cousins described above.
111 driver first appeared in
117 driver was originally written by
118 .An Konstantin Belousov Aq Mt kib@FreeBSD.org ,
120 .An D. Scott Phillips Aq Mt scottph@FreeBSD.org .
124 driver does not utilize the Block Window interface, so if a write to an
125 NVDIMM is interrupted due to a system crash or power outage,
126 the corresponding page might be left in a partially updated state.
128 There is no support for Device-Specific Methods (DSM), used to report and
129 control device health and wearing.
131 The driver depends on the
133 pmap interface, which is currently only implemented on amd64.
134 The interface can be only reasonable implemented on 64bit architectures.