diff options
Diffstat (limited to 'share')
-rw-r--r-- | share/man/man4/scsi.4 | 79 |
1 files changed, 51 insertions, 28 deletions
diff --git a/share/man/man4/scsi.4 b/share/man/man4/scsi.4 index fccb935..ad52663 100644 --- a/share/man/man4/scsi.4 +++ b/share/man/man4/scsi.4 @@ -24,15 +24,15 @@ .\" SUCH DAMAGE. .\" .\" $FreeBSD$ -.Dd October 15, 1998 -.Dt SCSI 4 +.Dd March 4, 2010 +.Dt CAM 4 .Os .Sh NAME -.Nm SCSI , .Nm CAM -.Nd CAM SCSI subsystem +.Nd Common Access Method SCSI/ATA subsystem .Sh SYNOPSIS .Cd "device scbus" +.Cd "device ada" .Cd "device cd" .Cd "device ch" .Cd "device da" @@ -49,31 +49,32 @@ .Cd "options SCSI_NO_OP_STRINGS" .Cd "options SCSI_DELAY=8000" .Sh DESCRIPTION -The CAM -.Tn SCSI +The +.Nm subsystem provides a uniform and modular system for the implementation of drivers to control various .Tn SCSI +and +.Tn ATA devices, and to utilize different .Tn SCSI +and +.Tn ATA host adapters through host adapter drivers. -When the system probes the -.Tn SCSI -busses, it attaches any devices it finds to the appropriate -drivers. +When the system probes busses, it attaches any devices it finds to the +appropriate drivers. The .Xr pass 4 -driver, if it is configured in the kernel, will attach to all -.Tn SCSI -devices. +driver, if it is configured in the kernel, will attach to all devices. .Sh KERNEL CONFIGURATION There are a number of generic kernel configuration options for the -CAM -.Tn SCSI +.Nm subsystem: .Bl -tag -width SCSI_NO_SENSE_STRINGS .It Dv CAMDEBUG -This option enables the CAM debugging printf code. +This option enables the +.Nm +debugging printf code. This will not actually cause any debugging information to be printed out when included by itself. Enabling printouts requires additional configuration. @@ -82,12 +83,11 @@ See below for details. This sets the maximum allowable number of concurrent "high power" commands. A "high power" command is a command that takes more electrical power than most to complete. -An example of this (and the only command currently -tagged as "high power") is the +An example of this is the .Tn SCSI START UNIT command. -Starting a SCSI disk often takes significantly more -electrical power than normal operation of the disk. +Starting a disk often takes significantly more electrical power than normal +operation. This option allows the user to specify how many concurrent high power commands may be outstanding without overloading the power supply on his computer. @@ -120,7 +120,9 @@ problems. This is the .Tn SCSI "bus settle delay." -In CAM, it is specified in +In +.Nm , +it is specified in .Em milliseconds , not seconds like the old .Tn SCSI @@ -148,7 +150,7 @@ In that case, the will be reset to 100ms. .El .Pp -All devices and the SCSI busses support boot time allocation so that +All devices and busses support dynamic allocation so that an upper number of devices and controllers does not need to be configured; .Cd "device da" will suffice for any number of disk drivers. @@ -204,7 +206,9 @@ hint.da.0.unit="0" This assigns .Em da0 to target 0, unit (lun) 0 of scbus 0. -Omitting the target or unit hints will instruct CAM to treat them as wildcards +Omitting the target or unit hints will instruct +.Nm +to treat them as wildcards and use the first respective counted instances. These examples can be combined together to allow a peripheral device to be wired to any particular controller, bus, target, and/or unit instance. @@ -221,7 +225,9 @@ The system allows common device drivers to work through many different types of adapters. The adapters take requests from the upper layers and do all IO between the -.Em SCSI +.Tn SCSI +or +.Tn ATA bus and the system. The maximum size of a transfer is governed by the adapter. @@ -233,7 +239,8 @@ Some adapters support in which the system is capable of operating as a device, responding to operations initiated by another system. Target mode is supported for -some adapters, but is not yet complete for this version of the CAM +some adapters, but is not yet complete for this version of the +.Nm .Tn SCSI subsystem. .Sh FILES @@ -278,7 +285,9 @@ Users can enable debugging from their kernel config file, by using the following kernel config options: .Bl -tag -width CAM_DEBUG_TARGET .It Dv CAMDEBUG -This enables CAM debugging. +This enables +.Nm +debugging. Without this option, users will not even be able to turn on debugging from userland via .Xr camcontrol 8 . @@ -313,9 +322,12 @@ See .Xr camcontrol 8 for details. .Sh SEE ALSO +.Xr ada 4 , .Xr aha 4 , .Xr ahb 4 , .Xr ahc 4 , +.Xr ahci 4 , +.Xr ata 4 , .Xr bt 4 , .Xr cd 4 , .Xr ch 4 , @@ -326,15 +338,26 @@ for details. .Xr xpt 4 , .Xr camcontrol 8 .Sh HISTORY -The CAM +The +.Nm .Tn SCSI subsystem first appeared in .Fx 3.0 . +The +.Nm +ATA support was added in +.Fx 8.0 . .Sh AUTHORS .An -nosplit -The CAM +The +.Nm .Tn SCSI subsystem was written by .An Justin Gibbs and .An Kenneth Merry . +The +.Nm +.Tn ATA +support was added by +.An Alexander Motin Aq mav@FreeBSD.org . |