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%
% Copyright (c) 1997-1998 University of Utah and the Flux Group.
% All rights reserved.
%
% The University of Utah grants you the right to copy and reproduce this
% document or portions thereof for academic, research, evaluation, and
% personal use only, provided that (1) the title page appears prominently,
% and (2) these copyright and permission notices are retained in all copies.
% To arrange for alternate terms, contact the University of Utah at
% csl-dist@cs.utah.edu or +1-801-585-3271.
%
\label{libfdev}
{\em This chapter is extremely incomplete;
it is basically only a bare skeleton.}
% Left in for amusement.
% {\em Implementation is in progress and an initial snapshot
% should be available in August.} % the year is yet to be determined
\section{Introduction}
This library provides default implementations
of various functions needed by device drivers
under the \oskit{} device driver framework.
These default implementations can be used by the host OS, if appropriate,
to make it easier to adopt the driver framework.
The facilities provided include:
\begin{itemize}
\item Hardware resource management and tracking functions
to allocate and free IRQs, I/O ports, DMA channels, etc.
\item Device namespace management
\item Memory allocation for device drivers
\item Data buffer management
\end{itemize}
\com{ XXX should be stated in the particular sections that do the assuming.
The library makes the following assumptions:
\begin{itemize}
\item Device I/O ports can be directly accessed.
\item The library has sole responsibility for management of I/O ports
and DMA channels
\item Virtual to physical mappings are {\em exactly} the same
\item Poll and yield operations are supported
\item Unix style naming
\end{itemize}
}
XXX: oskit_dev_init()
call this to init libdev
XXX: oskit_dev_probe()
call this after init to probe for devices
\section{Device Registration}
\label{fdev-default-reg}
XXX Builds a hardware tree.
An example hardware tree is shown in Figure~\ref{fig-fdev-hw-tree}.
\psfigure{fdev-hw-tree}{Example Hardware Tree}
Roughly...
the library is initialized through a call to {\tt oskit_dev_init}.
It first does auto-configuration by calling the
initialization and probe routines of the different driver sets.
After auto-configuration, it builds a device tree representing
the topology of the machine. While building the tree, it also
organizes the drivers into ``driver sets.'' A driver set consists
of driver that share a common set of properties. After initialization,
the library is ready to perform I/O requests for the OS.
\funcproto void oskit_dev_init(void);
This function initializes the library.
\section{Naming}
\label{fdev-naming}
{\em To be done.}
\com{
This doesn't exist as such.
The given fxn name takes an iid, not a string.
The library provides a convenient function to search the hardware tree
and find specific device nodes given Unix-style device names.
For example, given the string `{\tt hd0}' (BSD-style)
or `{\tt hda}' (Linux-style),
this function returns a pointer to the device node
for the first IDE hard disk it finds in the hardware tree.
\funcproto oskit_error_t *osenv_device_lookup(const~char *name);
XXX describe
}%com
\section{Memory Allocation}
Default implementation uses the LMM.
\section{Buffer Management}
Provides a ``simple buffer'' implementation,
in which buffers are simply regions
of physically- and virtually-contiguous physical memory.
\section{Processor Bus Resource Management}
XXX to allocate and free IRQs, I/O ports, DMA channels, etc.
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