Some SCSI HBAs support devices on multiple SCSI buses, such as those controlled
by the Solaris
mlx and
chs drivers. The bus on which
a particular device resides is represented in the boot path using the
mscsi
(multiple SCSI) bus nexus driver.
The number of the bus is indicated by the number associated with the
mscsi
bus nexus driver. So, for example, to indicate channel 3 of the PCI mlx
device, the mscsi@3 component is added to the boot path:
/devices/pci@0,0/pci1069,1@5/mscsi@3/cmdk@0,0:a
The realmode driver supplies the boot path in the
user_bootpath[]
field of the
bef_dev structure. Then, the kernel initialization
uses this field, if present, to construct the boot path.
Realmode drivers that want to add the mscsi component to the
boot path can do so by providing a partial or full boot path in the user_bootpath[]
field. Providing just the bus component, such as mscsi@3, frees
the realmode driver from the task of fully constructing the boot path.
