diff options
Diffstat (limited to 'share/man/man4')
| -rw-r--r-- | share/man/man4/atapiscsi.4 | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/share/man/man4/atapiscsi.4 b/share/man/man4/atapiscsi.4 index 331b5fe3a6d..62e1a537da2 100644 --- a/share/man/man4/atapiscsi.4 +++ b/share/man/man4/atapiscsi.4 @@ -1,4 +1,4 @@ -.\" $OpenBSD: atapiscsi.4,v 1.6 2000/07/10 13:27:34 aaron Exp $ +.\" $OpenBSD: atapiscsi.4,v 1.7 2001/04/05 20:10:39 deraadt Exp $ .\" .\" Copyright (c) 1999 Constantine Sapuntzakis. .\" @@ -34,8 +34,8 @@ .Nm atapiscsi .Nd ATAPI<->SCSI adapter .Sh SYNOPSIS -.Cd "atapiscsi* at wdc? channel ?" -.Cd "atapiscsi* at pciide? channel ?" +.Cd "atapiscsi* at wdc? channel ? flags 0x0000" +.Cd "atapiscsi* at pciide? channel ? flags 0x0000" .Cd "scsibus* at atapiscsi?" .Sh DESCRIPTION The @@ -63,6 +63,31 @@ devices do not support it. There is only one command outstanding on a cable at a time. For example, if a hard disk and a CD drive are placed on the same cable, the hard disk requests may get queued behind slower CD operations. +.Pp +The +.Cm flags +are used only with controllers that support DMA operations and +mode settings (like some +.Xr pciide 4 +controllers). +The lowest order (rightmost) nibble of the +.Cm flags +define the PIO mode to use. The next four bits indicate the DMA mode and the +third nibble the UltraDMA mode. +.Pp +For each set of four bits, the 3 lower bits define the mode to use +and the last bit must be set to 1 for this setting to be used. +For DMA and UltraDMA, 0xf (1111) means +.Dq disable . +For example, a +.Cm flags +value of 0x0fac (1111 1010 1100) +means +.Do +use PIO mode 4, DMA mode 2, disable UltraDMA +.Dc . +The special setting 0x0000 means +.Dq use whatever the drive claims to support . .Sh SEE ALSO .Xr cd 4 , .Xr intro 4 , |