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/**
* @file
*
* This file contains the basic algorithms for all assembly code used
* in an specific CPU port of RTEMS. These algorithms must be implemented
* in assembly language
*/
/*
* COPYRIGHT (c) 1989-2012.
* 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.rtems.org/license/LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#if 0
/**
* This routine is responsible for saving the FP context
* at *fp_context_ptr. If the point to load the FP context
* from is changed then the pointer is modified by this routine.
*
* Sometimes a macro implementation of this is in cpu.h which dereferences
* the ** and a similarly named routine in this file is passed something
* like a (Context_Control_fp *). The general rule on making this decision
* is to avoid writing assembly language.
*
* v850 Specific Information:
*
* The v850 appears to always have soft float.
*/
void _CPU_Context_save_fp(
Context_Control_fp **fp_context_ptr
)
{
}
/**
* This routine is responsible for restoring the FP context
* at *fp_context_ptr. If the point to load the FP context
* from is changed then the pointer is modified by this routine.
*
* Sometimes a macro implementation of this is in cpu.h which dereferences
* the ** and a similarly named routine in this file is passed something
* like a (Context_Control_fp *). The general rule on making this decision
* is to avoid writing assembly language.
*
* v850 Specific Information:
*
* XXX document implementation including references if appropriate
*/
void _CPU_Context_restore_fp(
Context_Control_fp **fp_context_ptr
)
{
}
#endif
/**
* This routine performs a normal non-FP context switch.
*
* v850 Specific Information:
*
* + r6 - running thread
* + r7 - heir thread
*/
#define V850_CONTEXT_CONTROL_R1_OFFSET 0
#define V850_CONTEXT_CONTROL_R3_OFFSET 4
#define V850_CONTEXT_CONTROL_R20_OFFSET 8
#define V850_CONTEXT_CONTROL_R21_OFFSET 12
#define V850_CONTEXT_CONTROL_R22_OFFSET 16
#define V850_CONTEXT_CONTROL_R23_OFFSET 20
#define V850_CONTEXT_CONTROL_R24_OFFSET 24
#define V850_CONTEXT_CONTROL_R25_OFFSET 28
#define V850_CONTEXT_CONTROL_R26_OFFSET 32
#define V850_CONTEXT_CONTROL_R27_OFFSET 36
#define V850_CONTEXT_CONTROL_R28_OFFSET 40
#define V850_CONTEXT_CONTROL_R29_OFFSET 44
#define V850_CONTEXT_CONTROL_R31_OFFSET 48
#define V850_CONTEXT_CONTROL_PSW_OFFSET 52
.section .text
.global __CPU_Context_switch
.type __CPU_Context_switch, @function
__CPU_Context_switch:
st.w r1,V850_CONTEXT_CONTROL_R1_OFFSET[r6]
st.w r3,V850_CONTEXT_CONTROL_R3_OFFSET[r6]
st.w r20,V850_CONTEXT_CONTROL_R20_OFFSET[r6]
st.w r21,V850_CONTEXT_CONTROL_R21_OFFSET[r6]
st.w r22,V850_CONTEXT_CONTROL_R22_OFFSET[r6]
st.w r23,V850_CONTEXT_CONTROL_R23_OFFSET[r6]
st.w r24,V850_CONTEXT_CONTROL_R24_OFFSET[r6]
st.w r25,V850_CONTEXT_CONTROL_R25_OFFSET[r6]
st.w r26,V850_CONTEXT_CONTROL_R27_OFFSET[r6]
st.w r27,V850_CONTEXT_CONTROL_R27_OFFSET[r6]
st.w r28,V850_CONTEXT_CONTROL_R28_OFFSET[r6]
st.w r29,V850_CONTEXT_CONTROL_R29_OFFSET[r6]
st.w r31,V850_CONTEXT_CONTROL_R31_OFFSET[r6]
stsr psw,r21
st.w r21,V850_CONTEXT_CONTROL_PSW_OFFSET[r6]
restore:
ld.w V850_CONTEXT_CONTROL_R1_OFFSET[r7],r1
ld.w V850_CONTEXT_CONTROL_R3_OFFSET[r7],r3
ld.w V850_CONTEXT_CONTROL_R20_OFFSET[r7],r20
ld.w V850_CONTEXT_CONTROL_R21_OFFSET[r7],r21
ld.w V850_CONTEXT_CONTROL_R22_OFFSET[r7],r22
ld.w V850_CONTEXT_CONTROL_R23_OFFSET[r7],r23
ld.w V850_CONTEXT_CONTROL_R24_OFFSET[r7],r24
ld.w V850_CONTEXT_CONTROL_R25_OFFSET[r7],r25
ld.w V850_CONTEXT_CONTROL_R27_OFFSET[r7],r26
ld.w V850_CONTEXT_CONTROL_R27_OFFSET[r7],r27
ld.w V850_CONTEXT_CONTROL_R28_OFFSET[r7],r28
ld.w V850_CONTEXT_CONTROL_R29_OFFSET[r7],r29
ld.w V850_CONTEXT_CONTROL_R31_OFFSET[r7],r31
ld.w V850_CONTEXT_CONTROL_PSW_OFFSET[r7],r7
ldsr r7,psw
jmp [r31]
/**
* This routine is generally used only to restart self in an
* efficient manner. It may simply be a label in _CPU_Context_switch.
*
* NOTE: May be unnecessary to reload some registers.
*
* v850 Specific Information:
*
* Move second parameter to first and jump to normal restore
*/
.section .text
.global __CPU_Context_restore
.type __CPU_Context_restore, @function
__CPU_Context_restore:
mov r6, r7 /* move to second parameter register */
br restore
#if 0
/**
* This routine provides the RTEMS interrupt management.
*
* v850 Specific Information:
*
* XXX document implementation including references if appropriate
*/
void _ISR_Handler(void); /* C warning avoidance */
void _ISR_Handler(void)
{
/*
* This discussion ignores a lot of the ugly details in a real
* implementation such as saving enough registers/state to be
* able to do something real. Keep in mind that the goal is
* to invoke a user's ISR handler which is written in C and
* uses a certain set of registers.
*
* Also note that the exact order is to a large extent flexible.
* Hardware will dictate a sequence for a certain subset of
* _ISR_Handler while requirements for setting
*/
/*
* At entry to "common" _ISR_Handler, the vector number must be
* available. On some CPUs the hardware puts either the vector
* number or the offset into the vector table for this ISR in a
* known place. If the hardware does not give us this information,
* then the assembly portion of RTEMS for this port will contain
* a set of distinct interrupt entry points which somehow place
* the vector number in a known place (which is safe if another
* interrupt nests this one) and branches to _ISR_Handler.
*
* save some or all context on stack
* may need to save some special interrupt information for exit
*
* #if ( CPU_HAS_SOFTWARE_INTERRUPT_STACK == TRUE )
* if ( _ISR_Nest_level == 0 )
* switch to software interrupt stack
* #endif
*
* _ISR_Nest_level++;
*
* _Thread_Dispatch_disable_level++;
*
* (*_ISR_Vector_table[ vector ])( vector );
*
* _Thread_Dispatch_disable_level--;
*
* --_ISR_Nest_level;
*
* if ( _ISR_Nest_level )
* goto the label "exit interrupt (simple case)"
*
* if ( _Thread_Dispatch_disable_level )
* goto the label "exit interrupt (simple case)"
*
* if ( _Thread_Dispatch_necessary ) {
* call _Thread_Dispatch() or prepare to return to _ISR_Dispatch
* prepare to get out of interrupt
* return from interrupt (maybe to _ISR_Dispatch)
*
* LABEL "exit interrupt (simple case):
* #if ( CPU_HAS_SOFTWARE_INTERRUPT_STACK == TRUE )
* if outermost interrupt
* restore stack
* #endif
* prepare to get out of interrupt
* return from interrupt
*/
}
#endif
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