HDH(4) BSD/vax Kernel Interfaces Manual HDH(4)NAMEhdh — ACC IF-11/HDH IMP interface
device hdh0 at uba0 csr 166740 vector hdhintr
The hdh device provides an HDLC Host (HDH) interface to an IMP. It is
normally used when participating in the DARPA Internet. The controller
itself is not accessible to users, but instead provides the hardware sup‐
port to the IMP interface described in imp(4). The configuration entry
for the IMP must also include the pseudo-device as shown above in the
hdh%d: not alive. The initialization routine was entered even though the
device did not autoconfigure. This indicates a system problem.
hdh%d: cannot get chan %d uba resources. Insufficient UNIBUS resources
existed to initialize the device. This is likely to be a shortage of
UNIBUS mapping registers.
hdh%d: LINE UP. This indicates that both the HDLC and HDH protocols have
declared the link to the IMP alive.
hdh%d: LINE DOWN. This indicates that the link to the IMP has died.
hdh%d: HOST DATA ERROR.
hdh%d: IMP SEQUENCE ERROR.
hdh%d: HOST SEQUENCE ERROR. These errors indicate that an HDH protocol
error has been detected.
hdh%d: cannot get supervisor cmnd buffer. This error indicates that an
mbuf could not be allocated to send a command to the IF-11/HDH.
Any other error message from hdh%d: indicates a serious error detected by
either the driver or the IF-11/HDH firmware.
The hdh driver appeared in 4.3BSD.
4.3 Berkeley Distribution June 5, 1993 4.3 Berkeley Distribution