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/*
* PowerPC CPU Dependent Source
*
* Author: Andrew Bray <andy@i-cubed.co.uk>
*
* COPYRIGHT (c) 1995 by i-cubed ltd.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of i-cubed limited not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* i-cubed limited makes no representations about the suitability
* of this software for any purpose.
*
* Derived from c/src/exec/cpu/no_cpu/cpu.c:
*
* COPYRIGHT (c) 1989-1997.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be found in
* the file LICENSE in this distribution or at
* http://www.OARcorp.com/rtems/license.html.
*
* $Id$
*/
#include <rtems/system.h>
#include <rtems/score/isr.h>
#include <rtems/score/context.h>
#include <rtems/score/thread.h>
#include <rtems/score/interr.h>
/* _CPU_Initialize
*
* This routine performs processor dependent initialization.
*
* INPUT PARAMETERS:
* cpu_table - CPU table to initialize
* thread_dispatch - address of disptaching routine
*/
void _CPU_Initialize(
rtems_cpu_table *cpu_table,
void (*thread_dispatch) /* ignored on this CPU */
)
{
_CPU_Table = *cpu_table;
}
/*PAGE
*
* _CPU_Context_Initialize
*/
void _CPU_Context_Initialize(
Context_Control *the_context,
unsigned32 *stack_base,
unsigned32 size,
unsigned32 new_level,
void *entry_point,
boolean is_fp
)
{
unsigned32 msr_value;
unsigned32 sp;
sp = (unsigned32)stack_base + size - CPU_MINIMUM_STACK_FRAME_SIZE;
*((unsigned32 *)sp) = 0;
the_context->gpr1 = sp;
_CPU_MSR_GET( msr_value );
if (!(new_level & CPU_MODES_INTERRUPT_MASK)) {
msr_value |= MSR_EE;
}
else {
msr_value &= ~MSR_EE;
}
the_context->msr = msr_value;
/*
* The FP bit of the MSR should only be enabled if this is a floating
* point task. Unfortunately, the vfprintf_r routine in newlib
* ends up pushing a floating point register regardless of whether or
* not a floating point number is being printed. Serious restructuring
* of vfprintf.c will be required to avoid this behavior. At this
* time (7 July 1997), this restructuring is not being done.
*/
/* Till Straumann: For deferred FPContext save/restore, make sure integer
* tasks have no FPU access in order to catch violations.
* Otherwise, the FP registers may be corrupted.
* Since we set the_contex->msr using our current MSR,
* we must make sure MSR_FP is off if (!is_fp)...
*/
#if defined(CPU_USE_DEFERRED_FP_SWITCH) && (CPU_USE_DEFERRED_FP_SWITCH==TRUE)
if ( is_fp )
#endif
the_context->msr |= PPC_MSR_FP;
#if defined(CPU_USE_DEFERRED_FP_SWITCH) && (CPU_USE_DEFERRED_FP_SWITCH==TRUE)
else
the_context->msr &= ~PPC_MSR_FP;
#endif
the_context->pc = (unsigned32)entry_point;
}
/*PAGE
*
* _CPU_Install_interrupt_stack
*/
void _CPU_Install_interrupt_stack( void )
{
}
/*PAGE
*
* This is the PowerPC specific implementation of the routine which
* returns TRUE if an interrupt is in progress.
*/
boolean _ISR_Is_in_progress( void )
{
register unsigned int isr_nesting_level;
/*
* Move from special purpose register 0 (mfspr SPRG0, r3)
*/
asm volatile ("mfspr %0, 272" : "=r" (isr_nesting_level));
return isr_nesting_level;
}
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