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/*
* Copyright (c) 1998, 1999 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/*
* Task switch code.
*/
#include <oskit/config.h>
#include <oskit/arm32/asm.h>
#include <oskit/arm32/paging.h>
#include <oskit/arm32/softfloat.h>
#include <threads/pthread_internal.h>
#include <threads/arm32/pcb.h>
/*
* r0 - next thread pointer.
* r1 - lock pointer. Ignored.
* r2 - current thread pointer.
*/
ENTRY(thread_switch_realmode)
/*
* Save current context
*/
ldr r3, [r2, #THREAD_PPCB]
add r3, r3, #PCB_R4
/* Store integer registers */
stmia r3, {r4-r14}
#ifndef SOFTFLOAT
#error "Need floating point support in thread switch!"
#endif
/*
* Save is done, switch to new thread.
*/
ldr r3, [r0, #THREAD_PPCB]
add r3, r3, #PCB_R4
/* Restore integer registers */
ldmia r3, {r4-r14}
#ifndef SOFTFLOAT
#error "Need floating point support in thread switch!"
#endif
/*
* Return to new thread's saved link register.
*
* XXX: The return value is the new thread. We depend on this
* little artifact for passing the thread pointer to the start
* routine for a new thread!
*/
mov r15, r14
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