85 lines
2.6 KiB
TeX
85 lines
2.6 KiB
TeX
\documentclass[11pt]{article}
|
|
\usepackage[T1]{fontenc}
|
|
\usepackage{amsmath, amsfonts, amssymb, amsthm, url, algorithmicx,
|
|
algpseudocode, lmodern, color, graphicx}
|
|
|
|
\title{Redox and system calls -- a multi-level kernel space}
|
|
\author{Redox OS developers}
|
|
\date{\today}
|
|
|
|
\begin{document}
|
|
\maketitle
|
|
|
|
%%% DISCLAIMER %%%
|
|
|
|
\begin{titlepage}
|
|
\centering \huge\bfseries The following document is an incomplete draft.
|
|
\end{titlepage}
|
|
|
|
%%% START OF DOCUMENT %%%
|
|
|
|
\maketitle
|
|
|
|
\begin{abstract}
|
|
In this paper, we review Redox's core system call interface. Redox has
|
|
multiple levels of kernel space, and the top one consists of a very
|
|
minimal system call interface, which we go over here.
|
|
\end{abstract}
|
|
|
|
\section{Introduction}
|
|
TODO
|
|
|
|
\section{Executing system calls}
|
|
We allow multiplied system calls, a generalized version of concept of
|
|
multicalls in the \emph{kqueue} system call.
|
|
|
|
Depending on the platform, system calls might be sent through interrupts or
|
|
\texttt{sysenter}. What we are really interested in, though, is the state
|
|
when we leave user space.
|
|
|
|
\begin{description}
|
|
\item [\texttt{rax}/\texttt{eax}] stores the pointer to the array of system calls.
|
|
\item [\texttt{rbx}/\texttt{ebx}] stores the number of system calls in
|
|
this bundle.
|
|
\end{description}
|
|
|
|
\section{The interface}
|
|
Each entry in this system call bundle buffer needs an ABI representation.
|
|
We represent the interface for the \emph{core system calls}.
|
|
|
|
The representation is as follows:
|
|
|
|
\begin{description}
|
|
\item [The system call ID] this is an unsigned 16-bit integer
|
|
representing which system call is used.
|
|
\item [First argument] this 64-bit integer is used as defined by the
|
|
system call.
|
|
\item [Second argument] this 64-bit integer is used as defined by the
|
|
system call.
|
|
\end{description}
|
|
|
|
The return value of the system call is placed in the respective element.
|
|
|
|
\subsection{Access management}
|
|
The memory access management is a set of system calls taken pointer and
|
|
size, respectively.
|
|
|
|
It contains of four calls:
|
|
|
|
\begin{description}
|
|
\item [Make memory readable].
|
|
\item [Make memory unreadable].
|
|
\item [Make memory writable].
|
|
\item [Make memory unwritable].
|
|
\item [Make memory executable].
|
|
\item [Make memory unexecutable].
|
|
\end{description}
|
|
|
|
\subsection{Access management}
|
|
|
|
%%% BIBLIOGRAPHY %%%
|
|
|
|
\begin{thebibliography}{9}
|
|
TODO
|
|
\end{thebibliography}
|
|
\end{document}
|