HP Vectra Technical Reference Manual page 451

G.7.1 HP_SHEADER Fields
DH--.A TR: Each bit in the DH--.A TR field indicates a property of the driver for device
mapping purposes. These bits are defined in table G.5.
Table G.5
Device Attributes Bits
Bit ATR Name Data
Description
15
ATLHP
1
The following bytes form a complete driver
header.
0
The bytes that follow are not a driver header.
14
ATLDEVCFG Reserved.
13
ATLISR
1
The driver can be mapped with
DH_V_PARENT.
12
ATLENTRY
1
The driver can be mapped with DH_V_CHILD.
11 :9
ATLTYPE_MASK
These three bits indicate the driver type.
ATLRSVD
000
This is a reserved vector.
ATLFREE
001
This is a free vector. The V_SYSTEM service
allocates free vectors to new drivers upon
request.
ATLSRVC
010
This driver is an EX-BIOS service.
ATLLOG
011
This is a logical driver. Its mapping direction is
from parent to child.
ATLIND
100
This is a mappable driver that cannot be the last
in the chain of drivers.
ATLBOT
101
This is a mappable driver that is the last in a
chain of drivers. This driver can only be a child
driver. This driver maps with ATLLOG,
ATLIND and ATLBOT drivers.
ATLINP
110
This driver is an input driver and is mappable.
111
Reserved
8
ATLSTRING Reserved
7
ATLMAP_CALL
1
This driver's SF_START subfunction should be
called whenever the driver is remapped.
442 Driver Writer's Guide