ahd - Adaptec PCI/PCI-X AIC79xx-based Ultra320 SCSI host
ahd* at pci? dev ? function ?
scsibus* at ahd?
This driver provides access to the SCSI bus(es) connected to
AIC79xx host adapter chips.
Driver features include support for narrow and wide buses,
ultra2, ultra160, and ultra320 synchronous transfers, packetized transfers,
tagged queuing, 512 SCBs, and target mode.
The ahd driver supports the following:
+o Adaptec AIC7901 host adapter chip
+o Adaptec AIC7901A host adapter chip
+o Adaptec AIC7902 host adapter chip
+o Adaptec 29320 host adapter
+o Adaptec 39320 host adapter
+o Many motherboards with on-board SCSI support
To compile in debugging code:
options AHD_DEBUG_OPTS=<bitmask of options>
To configure one or more controllers to assume the target
options AHD_TMODE_ENABLE=<bitmask of units>
The AHD_DEBUG_OPTS option is used to control which diagnostic messages
are printed to the console when AHD_DEBUG is enabled. Logically OR the
following bits together:
0x0001 Show miscellaneous information
0x0002 Show sense data
0x0004 Show Serial EEPROM contents
0x0008 Show bus termination settings
0x0010 Show host memory usage
0x0020 Show SCSI protocol messages
0x0040 Show mode pointer of the chip register window
0x0080 Show selection timeouts
0x0100 Show FIFO usage messages
0x0200 Show Queue Full status
0x0400 Show SCB queue status
0x0800 Show inbound packet information
0x1000 Show S/G list information
0x2000 Enable extra diagnostic code in the firmware
The AHD_REG_PRETTY_PRINT option compiles in support for human-readable
bit definitions for each register that is printed by the debugging code.
However, it also bloats the compiled size of the driver by
Individual controllers may be configured to operate in the
through the AHD_TMODE_ENABLE configuration option. The value assigned to
this option should be a bitmap of all units where target
mode is desired.
For example, a value of 0x25 would enable target mode on
units 0, 2, and
5. Note that target mode is only supported for ultra160
speeds and below.
Per target configuration performed in the SCSI-Select menu,
boot, is honored by this driver. This includes synchronous/asynchronous
transfers, maximum synchronous negotiation rate, wide transfers, disconnection,
and the host adapters SCSI ID.
ahc(4), cd(4), ch(4), intro(4), pci(4), scsi(4), sd(4),
The ahd driver was ported from FreeBSD 4.7 and first appeared in OpenBSD
The ahd driver, the AIC7xxx sequencer-code assembler, and
running on the aic79xx chips was written by Justin T. Gibbs.
OpenBSD port by Milos Urbanek, Kenneth R. Westerback & Marco
The current generation of 79xx chips do not support target
mode in Ultra320
mode. In this driver all target mode code has been
Currently there are issues with drives that run slower than
OpenBSD 3.6 July 5, 2004
[ Back ]