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Diffstat (limited to 'static/plan9-4e/man2/scsi.2')
| -rw-r--r-- | static/plan9-4e/man2/scsi.2 | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/static/plan9-4e/man2/scsi.2 b/static/plan9-4e/man2/scsi.2 new file mode 100644 index 00000000..081fe7a7 --- /dev/null +++ b/static/plan9-4e/man2/scsi.2 @@ -0,0 +1,184 @@ +.TH SCSI 2 +.SH NAME +openscsi, scsiready, scsi, scsicmd, scsierror \- SCSI device operations +.SH SYNOPSIS +.nf +.ft L +#include <u.h> +#include <libc.h> +#include <disk.h> +.ft +.PP +.ft L +typedef struct Scsi { + char *inquire; + int rawfd; + int nchange; + ulong changetime; +}; +.ft +.PP +.B +Scsi* openscsi(char *devdir) +.PP +.B +void closescsi(Scsi *s) +.PP +.B +int scsiready(Scsi *s) +.PP +.B +int scsi(Scsi *s, uchar *cmd, int ncmd, +.br + void *data, int ndata, int dir) +.PP +.B +int scsicmd(Scsi *s, uchar *cmd, int ncmd, +.br + void *data, int ndata, int dir) +.PP +.B +char* scsierror(int asc, int ascq) +.PP +.B +int scsiverbose; +.SH DESCRIPTION +These routines provide an interface +to a SCSI or ATAPI device via +.IR sd (3). +.PP +.I Openscsi +attempts to open the file +.IB devdir /raw +and use it to send raw SCSI commands. +On success, it reads the device's inquiry +string and stores it in in returned +.B Scsi +structure. +.I Closescsi +closes the connection and frees the +.B Scsi +structure. +.PP +.I Scsiready +sends the ``unit ready'' command up to three times, +returning zero if the unit responds that it is ready, +or \-1 on error. +.PP +.I Scsierror +returns a textual description of the SCSI status +denoted by the ASC and ASCQ sense codes. +The description is found by consulting +.BR /sys/lib/scsicodes . +The returned string will be overwritten by +the next call to +.IR scsierror . +.PP +.I Scsi +and +.I scsicmd +execute a single SCSI command on the named device. +There should be +.I ncmd +bytes of +command data in +.IR cmd ; +if +.I dir +is +.BR Sread , +a successful operation +will store up to +.I ndata +bytes into +.IR data , +returning the number of bytes stored. +If +.I dir +is +.BR Swrite , +the +.I ndata +bytes beginning at +.I data +are transmitted as the data argument to +the command, and the +number of bytes written is returned. +If +.I dir +is +.BR Snone , +.I data +and +.I ndata +are ignored. +On error, +.I scsi +and +.I scsicmd +return \-1. +.I Scsicmd +simply issues the command and +returns the result; +.I scsi +works a bit harder and +is the more commonly used routine. +.I Scsi +attempts to send the command; +if it is successful, +.I scsi +returns what +.I scsicmd +returned. +Otherwise, +.I scsi +sends a request sense command to +obtain the reason for the failure, +sends a unit ready command in +an attempt to bring the unit out of any +inconsistent states, and tries again. +If the second try fails, +.I scsi +sends the request +sense and unit ready commands +again +and then uses +.I scsierror +to set +.I errstr +with a reason for failure. +.PP +The +.B nchange +and +.B changetime +fields +in the +.B Scsi +structure +record the number of times a media +change has been detected, and the +time when the current media was +inserted into the drive (really the +first time a SCSI command was issued +after it was inserted). +They are maintained by +.IR scsi . +.PP +If +.I scsiverbose +is set, +these commands will produce a fair +amount of debugging output on file descriptor 2 +when SCSI commands fail. +.SH FILES +.TP +.B /sys/lib/scsicodes +List of textual messages corresponding to SCSI error codes; +consulted by +.BR scsierror . +.SH SOURCE +.B /sys/src/libdisk/scsi.c +.SH SEE ALSO +.IR sd (3), +.IR scuzz (8) |