ELANPAR(4) | Device Drivers Manual (i386) | ELANPAR(4)

# NAME

`elanpar` —
AMD Elan SC520 Programmable Address Regions

# SYNOPSIS

`elansc* at mainbus? bus ?`
`elanpar* at elansc?`

# DESCRIPTION

The `elanpar` driver supports the write-protect feature of the AMD Elan SC520 microcontroller's integrated Programmable Address Regions. Currently, `elanpar` protects the kernel text from being overwritten by the CPU or errant DMA.

# DIAGNOSTICS

elanpar0: cpu violated write-protect window %u
elanpar0: gp violated write-protect window %u
elanpar0: pci violated write-protect window %u

A Programmable Address Region stopped either the CPU, the general-purpose bus (gp), or a PCI bus master from writing to the indicated window of write-protected memory.

elanpar0: %u bytes of kernel text are unprotected

`elanpar` has not write-protected %u bytes of the kernel text.

# SEE ALSO

i386/elanpex(4), i386/elansc(4), dmesg(8), syslogd(8)

# HISTORY

The `elanpar` device first appeared in NetBSD 5.0.

# AUTHORS

The `elanpar` driver was written by David Young <dyoung@NetBSD.org>.

# BUGS

`elanpar` leaves as many as 65535 bytes unprotected at the beginning and end of kernel text. Also, `elanpar` is not compatible with setting breakpoints using ddb(4). Disable `elanpar` using `drvctl` `-d` elanpar0 before setting a breakpoint with ddb(4).

February 17, 2017 | NetBSD 9.0