1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<HTML> 3<HEAD> 4<META http-equiv="Content-Type" content="text/html; charset=windows-1252"> 5<META name="GENERATOR" content="IBM WebSphere Studio Homepage Builder Version 7.0.0.0 for Windows"> 6<META http-equiv="Content-Style-Type" content="text/css"> 7<TITLE>OS_SetUserExceptionHandler</TITLE> 8<LINK rel="stylesheet" href="../../css/nitro.css" type="text/css"> 9</HEAD> 10<BODY> 11<H1 align="left">OS_SetUserExceptionHandler <img src="../../image/NTR.gif" align="middle"><img src="../../image/TWL.gif" align="middle"></H1> 12<H2>Syntax</H2> 13<DL> 14 <DD> 15<PRE><CODE>#include <nitro/os.h></CODE></PRE> 16 <PRE><CODE>void OS_SetUserExceptionHandler( 17 OSExceptionHandler handler 18 void* arg ); 19 </CODE></PRE> 20</DL> 21<H2>Arguments</H2> 22<TABLE border="1" width="100%"> 23 <TBODY> 24 <TR> 25<TD width="13%"><CODE>handler</CODE></TD> 26<TD width="87%">Function to be called when an exception is generated</TD> 27 </TR> 28 <TR> 29<TD width="13%"><CODE>arg</CODE></TD> 30<TD width="87%">Argument used when calling the user function</TD> 31 </TR> 32 </TBODY> 33</TABLE> 34<H2>Return Values</H2> 35<P>None.</P> 36<H2>Description</H2> 37<P>Sets the user function that will be called when an exception is generated.</P> 38<P>The user function <code>handler</code> is of the type <CODE>OSExceptionHandler</CODE>.</P> 39<BLOCKQUOTE><CODE> typedef void (*OSExceptionHandler)( u32, void* );</CODE></BLOCKQUOTE> 40<P> This function is called when interrupts are prohibited.</P> 41<P>When calling the user function, the first argument is a pointer address to the structure the stores the generated exception's context. The second argument, <CODE>arg</CODE>, is specified by the second argument of <A href="OS_SetUserExceptionHandler.html"><CODE>OS_SetUserExceptionHandler</CODE></A>, which is passed unchanged.</P> 42<P><BR> 43<BR> 44<B>Contexts During Exceptions:</B></P> 45<P>The context of the function specified in the first argument is a pointer to a structure of type <CODE>OSExcpContext</CODE>.</P> 46<BLOCKQUOTE style="background-color:#ffffc0;"> 47<PRE> 48typedef struct 49{ 50 OSContext context; 51 u32 cp15; 52 u32 spsr; 53 u32 exinfo; 54} OSExcpContext;</PRE> 55 56</BLOCKQUOTE> 57<P> 58<ul><li>Here, <CODE>context</CODE> represents the values in a <CODE>OSContext</CODE>-type structure.<BR></li> 59<li><CODE>cp15</CODE> is the status of the coprocessor.</li> 60<li><CODE>spsr</CODE> is the SPSR. It will be undefined in modes that don't have SPSR.</li> 61<li><CODE>exinfo</CODE> indicates whether it is a reset or an exception. In the case of an exception, it will hold 0. In the case of a reset, it will hold a nonzero value.</li></ul> 62</P> 63<P><BR> 64<BR> 65<B>Exceptions with IS-TWL-DEBUGGER</B></P> 66<P>As described in <A href="about_exception.html">Overview (Exceptions)</A>, <FONT color="#ff0000"><B>it is not possible to display exception contexts or call users' exception handlers using IS-TWL-DEBUGGER. This cannot be done on IS-TWL-DEBUGGER, regardless of whether the application is running in TWL mode or NITRO mode.</B></FONT>The debugger will stop the CPU at the point when an exception occurs, so you can find out this information based on the information in the <B>Register</B> or <B>Call Stack</B> windows in the debugger.</P> 67<H2>See Also</H2> 68<P><A href="about_exception.html">Overview (Exceptions)</A><BR> 69<A href="OS_InitException.html"><CODE>OS_InitException</CODE></A><BR> 70<A href="../context/OS_InitContext.html"><CODE>OS_InitContext</CODE></A></P> 71<H2>Revision History</H2> 72<P>2008/04/18 Added a description of the context during an exception.<BR> 732005/03/08 Standardized how the term "interrupt" is written in Japanese.<BR> 742004/02/19 Initial value.</P> 75<hr><p>CONFIDENTIAL</p></body> 76</HTML>
