.\"-
.\" Copyright (c) 2012 SRI International
.\" All rights reserved.
.\"
.\" This software was developed by SRI International and the University of
.\" Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
.\" ("CTSRD"), as part of the DARPA CRASH research programme.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd August 3, 2012
.Dt ISF 4
.Os
.Sh NAME
.Nm isf
.Nd driver for Intel StrataFlash NOR flash devices
.Sh SYNOPSIS
.Cd "device isf"
.Pp
In
.Pa /boot/device.hints :
.Cd hint.isf.0.at="nexus0"
.Cd hint.isf.0.maddr=0x74000000
.Cd hint.isf.0.msize=0x2000000
.Sh DESCRIPTION
The
.Nm
device driver provides support for Intel StrataFlash NOR flash devices.
Devices are presented as
.Xr disk 9
devices and read access is supported along with limited write support.
Erasing blocks is supported the
.Dv ISF_ERASE
ioctl.
.Pp
The erase block size of
.Nm
devices is 128K.
NOR flash blocks contains all 1's after an erase cycle.
Writes to
.Nm
devices are allowed to succeed if and only if they all bits in the write
block (512-bytes) remain the same or transition from 1 to 0.
.Sh HARDWARE
The current version of the
.Nm
driver is known to support the 64MB part found on the Altera DE4 board.
It attempts to support other StrataFlash parts documented in the
datasheet, but those are untested.
.Sh IOCTLS
The
.Nm device
supports the
.Xr ioctl 2
command codes:
.Bl -tag -width ISF_ERASE
.It Dv ISF_ERASE
Erase one or more blocks.
.Dv ISF_ERASE is defined as follows:
.Bd -literal
	struct isf_range {
		off_t	ir_off;
		size_t	ir_size;
	};

	#define ISF_ERASE       _IOW('I', 1, struct isf_range)
.Ed
.Pp
The
.Li ir_off
member marks the beginning of the area to be erased and must fall on at 128K
boundary.
The
.Li ir_size
member indicates the size of the area to be erased and must a multiple
of 128K.
.El
.Sh SEE ALSO
.Xr isfctl 4 ,
.Xr disk 9
.Rs
.%T Intel StrataFlash Embedded Memory (P30)
.%D November 1, 2005
.%I Intel Corporation
.%U http://www.xilinx.com/products/boards/ml505/datasheets/30666604.pdf
.Re
.Sh HISTORY
The
.Nm
device driver first appeared in
.Fx 10.0 .
.Sh AUTHORS
The
.Nm
device driver and this manual page were
developed by SRI International and the University of Cambridge Computer
Laboratory under DARPA/AFRL contract
.Pq FA8750-10-C-0237
.Pq Do CTSRD Dc ,
as part of the DARPA CRASH research programme.
.Sh BUGS
While an erase is in progress, all read and write operations return
.Er EBUSY .
In principle, reads could be allowed outside the programming region the
blocked currently being erased resides in and writes could be allowed by
suspending the erase, but neither of these is currently implemented.
.Pp
Depending on the flash part ether the top or bottom 128K of the flash
address space is divided into 4 32K erase blocks.
The
.Nm
driver hides this from the user requiring that all erase requests be
multiples of 128K in size and erasing the individual blocks as needed at
the top or bottom.