SCSI(3) SCSI(3)
NAME
scsi - SCSI command interface
SYNOPSIS
bind #S /dev
/dev/scsiid
/dev/0/cmd
/dev/0/data
/dev/0/debug
...
DESCRIPTION
The scsi interface is accessed through a two-level direc-
tory. The scsiid file contains the SCSI id of the host
interface, typically 7, represented textually. Some imple-
mentations allow this to be changed by writing to the file;
in many cases, the higher-order bits are hardware specific.
Each SCSI target n (0≤n≤7) is associated with a subdirectory
#S/n containing files cmd, data, and debug. The following
steps may be used to execute a SCSI command:
The command block is written to the cmd file.
The data file is either written or read depending on
the direction of the transfer. (A command that
involves no data transfer is executed with a zero-
length write.)
The cmd file is read to retrieve the status of the com-
mand, returned as a 4-byte big-endian integer.
Writing an ASCII `1' to the debug file causes tracing infor-
mation to be written to /dev/klog; writing a `0' turns the
tracing off.
SEE ALSO
wren(3)
SOURCE
/sys/src/9/port/devscsi.c
/sys/src/9/*/scsi.c
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