/**
* @file
*
* @brief V850 CPU Department Source
*
* This include file contains information pertaining to the v850
* processor.
*/
/*
* 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.
*/
#ifndef _RTEMS_SCORE_CPU_H
#define _RTEMS_SCORE_CPU_H
#ifdef __cplusplus
extern "C" {
#endif
#include <rtems/score/basedefs.h>
#include <rtems/score/v850.h>
/* conditional compilation parameters */
/**
* Does the CPU follow the simple vectored interrupt model?
*
* If TRUE, then RTEMS allocates the vector table it internally manages.
* If FALSE, then the BSP is assumed to allocate and manage the vector
* table
*
* Port Specific Information:
*
* This port uses the Progammable Interrupt Controller interrupt model.
*/
#define CPU_SIMPLE_VECTORED_INTERRUPTS FALSE
#define CPU_HARDWARE_FP FALSE
#define CPU_SOFTWARE_FP FALSE
#define CPU_ALL_TASKS_ARE_FP FALSE
#define CPU_IDLE_TASK_IS_FP FALSE
#define CPU_USE_DEFERRED_FP_SWITCH FALSE
#define CPU_ENABLE_ROBUST_THREAD_DISPATCH FALSE
/**
* Does the stack grow up (toward higher addresses) or down
* (toward lower addresses)?
*
* If TRUE, then the grows upward.
* If FALSE, then the grows toward smaller addresses.
*
* Port Specific Information:
*
* The v850 stack grows from high addresses to low addresses.
*/
#define CPU_STACK_GROWS_UP FALSE
/* FIXME: Is this the right value? */
#define CPU_CACHE_LINE_BYTES 32
#define CPU_STRUCTURE_ALIGNMENT
/**
* @addtogroup RTEMSScoreCPUV850CPUInterrupt
* The following defines the number of bits actually used in the
* interrupt field of the task mode. How those bits map to the
* CPU interrupt levels is defined by the routine @ref _CPU_ISR_Set_level.
*
* Port Specific Information:
*
* The v850 only has a single bit in the CPU for interrupt disable/enable.
*/
#define CPU_MODES_INTERRUPT_MASK 0x00000001
#define CPU_MAXIMUM_PROCESSORS 32
/**
* @defgroup RTEMSScoreCPUV850CPUContext Processor Dependent Context Management
*
* @ingroup RTEMSScoreCPUV850
*
* From the highest level viewpoint, there are 2 types of context to save.
*
* -# Interrupt registers to save
* -# Task level registers to save
*
* Since RTEMS handles integer and floating point contexts separately, this
* means we have the following 3 context items:
*
* -# task level context stuff:: Context_Control
* -# floating point task stuff:: Context_Control_fp
* -# special interrupt level context :: CPU_Interrupt_frame
*
* On some processors, it is cost-effective to save only the callee
* preserved registers during a task context switch. This means
* that the ISR code needs to save those registers which do not
* persist across function calls. It is not mandatory to make this
* distinctions between the caller/callee saves registers for the
* purpose of minimizing context saved during task switch and on interrupts.
* If the cost of saving extra registers is minimal, simplicity is the
* choice. Save the same context on interrupt entry as for tasks in
* this case.
*
* Additionally, if gdb is to be made aware of RTEMS tasks for this CPU, then
* care should be used in designing the context area.
*
* On some CPUs with hardware floating point support, the Context_Control_fp
* structure will not be used or it simply consist of an array of a
* fixed number of bytes. This is done when the floating point context
* is dumped by a "FP save context" type instruction and the format
* is not really defined by the CPU. In this case, there is no need
* to figure out the exact format -- only the size. Of course, although
* this is enough information for RTEMS, it is probably not enough for
* a debugger such as gdb. But that is another problem.
*
* Port Specific Information:
*
* On the v850, this port saves special registers and those that are
* callee saved.
*/
/** @{ **/
/**
* This defines the minimal set of integer and processor state registers
* that must be saved during a voluntary context switch from one thread
* to another.
*/
typedef struct {
uint32_t r1;
/** This field is the stack pointer (e.g. r3). */
uint32_t r3_stack_pointer;
uint32_t r20;
uint32_t r21;
uint32_t r22;
uint32_t r23;
uint32_t r24;
uint32_t r25;
uint32_t r26;
uint32_t r27;
uint32_t r28;
uint32_t r29;
uint32_t r31;
uint32_t psw;
} Context_Control;
/**
* This macro returns the stack pointer associated with @a _context.
*
* @param[in] _context is the thread context area to access
*
* @return This method returns the stack pointer.
*/
#define _CPU_Context_Get_SP( _context ) \
(_context)->r3_stack_pointer
/**
* This defines the set of integer and processor state registers that must
* be saved during an interrupt. This set does not include any which are
* in @ref Context_Control.
*/
typedef struct {
/** This field is a hint that a port will have a number of integer
* registers that need to be saved when an interrupt occurs or
* when a context switch occurs at the end of an ISR.
*/
uint32_t special_interrupt_register;
} CPU_Interrupt_frame;
/** @} */
/**
* @defgroup RTEMSScoreCPUV850CPUInterrupt Processor Dependent Interrupt Management
*
* @ingroup RTEMSScoreCPUV850
*/
/** @{ **/
/**
* Amount of extra stack (above minimum stack size) required by
* MPCI receive server thread. Remember that in a multiprocessor
* system this thread must exist and be able to process all directives.
*
* Port Specific Information:
*
* There is no reason to think the v850 needs extra MPCI receive
* server stack.
*/
#define CPU_MPCI_RECEIVE_SERVER_EXTRA_STACK 0
/**
* This is defined if the port has a special way to report the ISR nesting
* level. Most ports maintain the variable @a _ISR_Nest_level.
*/
#define CPU_PROVIDES_ISR_IS_IN_PROGRESS FALSE
/** @} */
/**
* @addtogroup RTEMSScoreCPUV850CPUContext
* Should be large enough to run all RTEMS tests. This ensures
* that a "reasonable" small application should not have any problems.
*
* Port Specific Information:
*
* This should be very conservative on the v850.
*/
#define CPU_STACK_MINIMUM_SIZE (1024*4)
#define CPU_SIZEOF_POINTER 4
/**
* CPU's worst alignment requirement for data types on a byte boundary. This
* alignment does not take into account the requirements for the stack.
*
* Port Specific Information:
*
* There is no apparent reason why this should be larger than 8.
*/
#define CPU_ALIGNMENT 8
/**
* This number corresponds to the byte alignment requirement for the
* heap handler. This alignment requirement may be stricter than that
* for the data types alignment specified by @ref CPU_ALIGNMENT. It is
* common for the heap to follow the same alignment requirement as
* @ref CPU_ALIGNMENT. If the @ref CPU_ALIGNMENT is strict enough for
* the heap, then this should be set to @ref CPU_ALIGNMENT.
*
* @note This does not have to be a power of 2 although it should be
* a multiple of 2 greater than or equal to 2. The requirement
* to be a multiple of 2 is because the heap uses the least
* significant field of the front and back flags to indicate
* that a block is in use or free. So you do not want any odd
* length blocks really putting length data in that bit.
*
* On byte oriented architectures, @ref CPU_HEAP_ALIGNMENT normally will
* have to be greater or equal to than @ref CPU_ALIGNMENT to ensure that
* elements allocated from the heap meet all restrictions.
*
* Port Specific Information:
*
* There is no apparent reason why this should be larger than CPU_ALIGNMENT.
*/
#define CPU_HEAP_ALIGNMENT CPU_ALIGNMENT
/**
* The v850 has enough RAM where alignment to 16 may be desirable depending
* on the cache properties. But this remains to be demonstrated.
*/
#define CPU_STACK_ALIGNMENT 8
#define CPU_INTERRUPT_STACK_ALIGNMENT CPU_CACHE_LINE_BYTES
/*
* ISR handler macros
*/
/**
* @addtogroup RTEMSScoreCPUV850CPUInterrupt
*/
/** @{ **/
/**
* Disable all interrupts for an RTEMS critical section. The previous
* level is returned in @a _isr_cookie.
*
* @param[out] _isr_cookie will contain the previous level cookie
*
* Port Specific Information:
*
* On the v850, we need to save the PSW and use "di" to disable interrupts.
*/
#define _CPU_ISR_Disable( _isr_cookie ) \
do { \
unsigned int _psw; \
\
v850_get_psw( _psw ); \
__asm__ __volatile__( "di" ); \
_isr_cookie = _psw; \
} while (0)
/**
* Enable interrupts to the previous level (returned by _CPU_ISR_Disable).
* This indicates the end of an RTEMS critical section. The parameter
* @a _isr_cookie is not modified.
*
* @param[in] _isr_cookie contain the previous level cookie
*
* Port Specific Information:
*
* On the v850, we simply need to restore the PSW.
*/
#define _CPU_ISR_Enable( _isr_cookie ) \
do { \
unsigned int _psw = (_isr_cookie); \
\
v850_set_psw( _psw ); \
} while (0)
/**
* This temporarily restores the interrupt to @a _isr_cookie before immediately
* disabling them again. This is used to divide long RTEMS critical
* sections into two or more parts. The parameter @a _isr_cookie is not
* modified.
*
* @param[in] _isr_cookie contain the previous level cookie
*
* Port Specific Information:
*
* This saves at least one instruction over using enable/disable back to back.
*/
#define _CPU_ISR_Flash( _isr_cookie ) \
do { \
unsigned int _psw = (_isr_cookie); \
v850_set_psw( _psw ); \
__asm__ __volatile__( "di" ); \
} while (0)
RTEMS_INLINE_ROUTINE bool _CPU_ISR_Is_enabled( uint32_t level )
{
return ( level & V850_PSW_INTERRUPT_DISABLE_MASK )
!= V850_PSW_INTERRUPT_DISABLE;
}
/**
* This routine and @ref _CPU_ISR_Get_level
* Map the interrupt level in task mode onto the hardware that the CPU
* actually provides. Currently, interrupt levels which do not
* map onto the CPU in a generic fashion are undefined. Someday,
* it would be nice if these were "mapped" by the application
* via a callout. For example, m68k has 8 levels 0 - 7, levels
* 8 - 255 would be available for bsp/application specific meaning.
* This could be used to manage a programmable interrupt controller
* via the rtems_task_mode directive.
*
* Port Specific Information:
*
* On the v850, level 0 is enabled. Non-zero is disabled.
*/
#define _CPU_ISR_Set_level( new_level ) \
do { \
if ( new_level ) \
__asm__ __volatile__( "di" ); \
else \
__asm__ __volatile__( "ei" ); \
} while (0)
/**
* Return the current interrupt disable level for this task in
* the format used by the interrupt level portion of the task mode.
*
* @note This routine usually must be implemented as a subroutine.
*
* Port Specific Information:
*
* This method is implemented in C on the v850.
*/
uint32_t _CPU_ISR_Get_level( void );
/* end of ISR handler macros */
/** @} */
/* Context handler macros */
/**
* @addtogroup RTEMSScoreCPUV850CPUContext
* Initialize the context to a state suitable for starting a
* task after a context restore operation. Generally, this
* involves:
*
* - setting a starting address
* - preparing the stack
* - preparing the stack and frame pointers
* - setting the proper interrupt level in the context
* - initializing the floating point context
*
* This routine generally does not set any unnecessary register
* in the context. The state of the "general data" registers is
* undefined at task start time.
*
* @param[in] _the_context is the context structure to be initialized
* @param[in] _stack_base is the lowest physical address of this task's stack
* @param[in] _size is the size of this task's stack
* @param[in] _isr is the interrupt disable level
* @param[in] _entry_point is the thread's entry point. This is
* always @a _Thread_Handler
* @param[in] _is_fp is TRUE if the thread is to be a floating
* point thread. This is typically only used on CPUs where the
* FPU may be easily disabled by software such as on the SPARC
* where the PSR contains an enable FPU bit.
* @param[in] tls_area is the thread-local storage (TLS) area
*
* Port Specific Information:
*
* This method is implemented in C on the v850.
*/
void _CPU_Context_Initialize(
Context_Control *the_context,
uint32_t *stack_base,
uint32_t size,
uint32_t new_level,
void *entry_point,
bool is_fp,
void *tls_area
);
/**
* This routine is responsible for somehow restarting the currently
* executing task. If you are lucky, then all that is necessary
* is restoring the context. Otherwise, there will need to be
* a special assembly routine which does something special in this
* case. For many ports, simply adding a label to the restore path
* of @ref _CPU_Context_switch will work. On other ports, it may be
* possibly to load a few arguments and jump to the restore path. It will
* not work if restarting self conflicts with the stack frame
* assumptions of restoring a context.
*
* Port Specific Information:
*
* On the v850, we require a special entry point to restart a task.
*/
#define _CPU_Context_Restart_self( _the_context ) \
_CPU_Context_restore( (_the_context) );
/* XXX this should be possible to remove */
#if 0
/**
* This routine initializes the FP context area passed to it to.
* There are a few standard ways in which to initialize the
* floating point context. The code included for this macro assumes
* that this is a CPU in which a "initial" FP context was saved into
* @a _CPU_Null_fp_context and it simply copies it to the destination
* context passed to it.
*
* Other floating point context save/restore models include:
* -# not doing anything, and
* -# putting a "null FP status word" in the correct place in the FP context.
*
* @param[in] _destination is the floating point context area
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define _CPU_Context_Initialize_fp( _destination ) \
{ \
}
#endif
/* end of Context handler macros */
/* Fatal Error manager macros */
/**
* This routine copies _error into a known place -- typically a stack
* location or a register, optionally disables interrupts, and
* halts/stops the CPU.
*
* Port Specific Information:
*
* Move the error code into r10, disable interrupts and halt.
*/
#define _CPU_Fatal_halt( _source, _error ) \
do { \
__asm__ __volatile__ ( "di" ); \
__asm__ __volatile__ ( "mov %0, r10; " : "=r" ((_error)) ); \
__asm__ __volatile__ ( "halt" ); \
} while (0)
/* end of Fatal Error manager macros */
#define CPU_USE_GENERIC_BITFIELD_CODE TRUE
#define CPU_USE_LIBC_INIT_FINI_ARRAY FALSE
/* functions */
/**
* @brief CPU initialize.
* This routine performs CPU dependent initialization.
*
* Port Specific Information:
*
* This is implemented in C.
*
* v850 CPU Dependent Source
*/
void _CPU_Initialize(void);
void *_CPU_Thread_Idle_body( uintptr_t ignored );
/**
* @addtogroup RTEMSScoreCPUV850CPUContext
*/
/**@{**/
/**
* This routine switches from the run context to the heir context.
*
* @param[in] run points to the context of the currently executing task
* @param[in] heir points to the context of the heir task
*
* Port Specific Information:
*
* This is implemented in assembly on the v850.
*/
void _CPU_Context_switch(
Context_Control *run,
Context_Control *heir
);
/**
* This routine is generally used only to restart self in an
* efficient manner. It may simply be a label in @ref _CPU_Context_switch.
*
* @param[in] new_context points to the context to be restored.
*
* @note May be unnecessary to reload some registers.
*
* Port Specific Information:
*
* This is implemented in assembly on the v850.
*/
RTEMS_NO_RETURN void _CPU_Context_restore( Context_Control *new_context );
/* XXX this should be possible to remove */
#if 0
/**
* This routine saves the floating point context passed to it.
*
* @param[in] fp_context_ptr is a pointer to a pointer to a floating
* point context area
*
* @return on output @a *fp_context_ptr will contain the address that
* should be used with @ref _CPU_Context_restore_fp to restore this context.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
void _CPU_Context_save_fp(
Context_Control_fp **fp_context_ptr
);
#endif
/* XXX this should be possible to remove */
#if 0
/**
* This routine restores the floating point context passed to it.
*
* @param[in] fp_context_ptr is a pointer to a pointer to a floating
* point context area to restore
*
* @return on output @a *fp_context_ptr will contain the address that
* should be used with @ref _CPU_Context_save_fp to save this context.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
void _CPU_Context_restore_fp(
Context_Control_fp **fp_context_ptr
);
#endif
/** @} */
/* FIXME */
typedef CPU_Interrupt_frame CPU_Exception_frame;
void _CPU_Exception_frame_print( const CPU_Exception_frame *frame );
/**
* @defgroup RTEMSScoreCPUV850CPUEndian CPUEndian
*
* @ingroup RTEMSScoreCPUV850
*
* @brief CPUEndian
*/
/** @{ */
/**
* The following routine swaps the endian format of an unsigned int.
* It must be static because it is referenced indirectly.
*
* This version will work on any processor, but if there is a better
* way for your CPU PLEASE use it. The most common way to do this is to:
*
* swap least significant two bytes with 16-bit rotate
* swap upper and lower 16-bits
* swap most significant two bytes with 16-bit rotate
*
* Some CPUs have special instructions which swap a 32-bit quantity in
* a single instruction (e.g. i486). It is probably best to avoid
* an "endian swapping control bit" in the CPU. One good reason is
* that interrupts would probably have to be disabled to ensure that
* an interrupt does not try to access the same "chunk" with the wrong
* endian. Another good reason is that on some CPUs, the endian bit
* endianness for ALL fetches -- both code and data -- so the code
* will be fetched incorrectly.
*
* @param[in] value is the value to be swapped
* @return the value after being endian swapped
*
* Port Specific Information:
*
* The v850 has a single instruction to swap endianness on a 32 bit quantity.
*/
static inline uint32_t CPU_swap_u32(
uint32_t value
)
{
unsigned int swapped;
#if (V850_HAS_BYTE_SWAP_INSTRUCTION == 1)
unsigned int v;
v = value;
__asm__ __volatile__ ("bsw %0, %1" : "=r" (v), "=&r" (swapped) );
#else
uint32_t byte1, byte2, byte3, byte4;
byte4 = (value >> 24) & 0xff;
byte3 = (value >> 16) & 0xff;
byte2 = (value >> 8) & 0xff;
byte1 = value & 0xff;
swapped = (byte1 << 24) | (byte2 << 16) | (byte3 << 8) | byte4;
#endif
return swapped;
}
/**
* This routine swaps a 16 bir quantity.
*
* @param[in] value is the value to be swapped
* @return the value after being endian swapped
*
* Port Specific Information:
*
* The v850 has a single instruction to swap endianness on a 16 bit quantity.
*/
static inline uint16_t CPU_swap_u16( uint16_t value )
{
unsigned int swapped;
#if (V850_HAS_BYTE_SWAP_INSTRUCTION == 1)
unsigned int v;
v = value;
__asm__ __volatile__ ("bsh %0, %1" : "=r" (v), "=&r" (swapped) );
#else
swapped = ((value & 0xff) << 8) | ((value >> 8) & 0xff);
#endif
return swapped;
}
/** @} */
typedef uint32_t CPU_Counter_ticks;
uint32_t _CPU_Counter_frequency( void );
CPU_Counter_ticks _CPU_Counter_read( void );
static inline CPU_Counter_ticks _CPU_Counter_difference(
CPU_Counter_ticks second,
CPU_Counter_ticks first
)
{
return second - first;
}
/** Type that can store a 32-bit integer or a pointer. */
typedef uintptr_t CPU_Uint32ptr;
#ifdef __cplusplus
}
#endif
#endif
