/**
* @file
*
* @brief Blackfin CPU Department Source
*
* This include file contains information pertaining to the Blackfin
* processor.
*/
/*
* COPYRIGHT (c) 1989-2006.
* On-Line Applications Research Corporation (OAR).
* adapted to Blackfin by Alain Schaefer <alain.schaefer@easc.ch>
* and Antonio Giovanini <antonio@atos.com.br>
*
* 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/bfin.h>
/* conditional compilation parameters */
/**
* Does RTEMS manage a dedicated interrupt stack in software?
*
* If TRUE, then a stack is allocated in @ref _ISR_Handler_initialization.
* If FALSE, nothing is done.
*
* If the CPU supports a dedicated interrupt stack in hardware,
* then it is generally the responsibility of the BSP to allocate it
* and set it up.
*
* If the CPU does not support a dedicated interrupt stack, then
* the porter has two options: (1) execute interrupts on the
* stack of the interrupted task, and (2) have RTEMS manage a dedicated
* interrupt stack.
*
* If this is TRUE, @ref CPU_ALLOCATE_INTERRUPT_STACK should also be TRUE.
*
* Only one of @ref CPU_HAS_SOFTWARE_INTERRUPT_STACK and
* @ref CPU_HAS_HARDWARE_INTERRUPT_STACK should be set to TRUE. It is
* possible that both are FALSE for a particular CPU. Although it
* is unclear what that would imply about the interrupt processing
* procedure on that CPU.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_HAS_SOFTWARE_INTERRUPT_STACK TRUE
/*
* 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
*
* BFIN Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_SIMPLE_VECTORED_INTERRUPTS TRUE
/**
* Does this CPU have hardware support for a dedicated interrupt stack?
*
* If TRUE, then it must be installed during initialization.
* If FALSE, then no installation is performed.
*
* If this is TRUE, @ref CPU_ALLOCATE_INTERRUPT_STACK should also be TRUE.
*
* Only one of @ref CPU_HAS_SOFTWARE_INTERRUPT_STACK and
* @ref CPU_HAS_HARDWARE_INTERRUPT_STACK should be set to TRUE. It is
* possible that both are FALSE for a particular CPU. Although it
* is unclear what that would imply about the interrupt processing
* procedure on that CPU.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_HAS_HARDWARE_INTERRUPT_STACK FALSE
/**
* Does RTEMS allocate a dedicated interrupt stack in the Interrupt Manager?
*
* If TRUE, then the memory is allocated during initialization.
* If FALSE, then the memory is allocated during initialization.
*
* This should be TRUE is CPU_HAS_SOFTWARE_INTERRUPT_STACK is TRUE.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_ALLOCATE_INTERRUPT_STACK TRUE
/**
* Does the RTEMS invoke the user's ISR with the vector number and
* a pointer to the saved interrupt frame (1) or just the vector
* number (0)?
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_ISR_PASSES_FRAME_POINTER TRUE
/**
* @def CPU_HARDWARE_FP
*
* Does the CPU have hardware floating point?
*
* If TRUE, then the RTEMS_FLOATING_POINT task attribute is supported.
* If FALSE, then the RTEMS_FLOATING_POINT task attribute is ignored.
*
* If there is a FP coprocessor such as the i387 or mc68881, then
* the answer is TRUE.
*
* The macro name "NO_CPU_HAS_FPU" should be made CPU specific.
* It indicates whether or not this CPU model has FP support. For
* example, it would be possible to have an i386_nofp CPU model
* which set this to false to indicate that you have an i386 without
* an i387 and wish to leave floating point support out of RTEMS.
*/
/**
* @def CPU_SOFTWARE_FP
*
* Does the CPU have no hardware floating point and GCC provides a
* software floating point implementation which must be context
* switched?
*
* This feature conditional is used to indicate whether or not there
* is software implemented floating point that must be context
* switched. The determination of whether or not this applies
* is very tool specific and the state saved/restored is also
* compiler specific.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#if ( BLACKFIN_CPU_HAS_FPU == 1 )
#define CPU_HARDWARE_FP TRUE
#else
#define CPU_HARDWARE_FP FALSE
#endif
#define CPU_SOFTWARE_FP FALSE
/**
* Are all tasks RTEMS_FLOATING_POINT tasks implicitly?
*
* If TRUE, then the RTEMS_FLOATING_POINT task attribute is assumed.
* If FALSE, then the RTEMS_FLOATING_POINT task attribute is followed.
*
* So far, the only CPUs in which this option has been used are the
* HP PA-RISC and PowerPC. On the PA-RISC, The HP C compiler and
* gcc both implicitly used the floating point registers to perform
* integer multiplies. Similarly, the PowerPC port of gcc has been
* seen to allocate floating point local variables and touch the FPU
* even when the flow through a subroutine (like vfprintf()) might
* not use floating point formats.
*
* If a function which you would not think utilize the FP unit DOES,
* then one can not easily predict which tasks will use the FP hardware.
* In this case, this option should be TRUE.
*
* If @ref CPU_HARDWARE_FP is FALSE, then this should be FALSE as well.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_ALL_TASKS_ARE_FP FALSE
/**
* Should the IDLE task have a floating point context?
*
* If TRUE, then the IDLE task is created as a RTEMS_FLOATING_POINT task
* and it has a floating point context which is switched in and out.
* If FALSE, then the IDLE task does not have a floating point context.
*
* Setting this to TRUE negatively impacts the time required to preempt
* the IDLE task from an interrupt because the floating point context
* must be saved as part of the preemption.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_IDLE_TASK_IS_FP FALSE
/**
* Should the saving of the floating point registers be deferred
* until a context switch is made to another different floating point
* task?
*
* If TRUE, then the floating point context will not be stored until
* necessary. It will remain in the floating point registers and not
* disturned until another floating point task is switched to.
*
* If FALSE, then the floating point context is saved when a floating
* point task is switched out and restored when the next floating point
* task is restored. The state of the floating point registers between
* those two operations is not specified.
*
* If the floating point context does NOT have to be saved as part of
* interrupt dispatching, then it should be safe to set this to TRUE.
*
* Setting this flag to TRUE results in using a different algorithm
* for deciding when to save and restore the floating point context.
* The deferred FP switch algorithm minimizes the number of times
* the FP context is saved and restored. The FP context is not saved
* until a context switch is made to another, different FP task.
* Thus in a system with only one FP task, the FP context will never
* be saved or restored.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_USE_DEFERRED_FP_SWITCH TRUE
#define CPU_ENABLE_ROBUST_THREAD_DISPATCH FALSE
/**
* Does this port provide a CPU dependent IDLE task implementation?
*
* If TRUE, then the routine @ref _CPU_Thread_Idle_body
* must be provided and is the default IDLE thread body instead of
* @ref _CPU_Thread_Idle_body.
*
* If FALSE, then use the generic IDLE thread body if the BSP does
* not provide one.
*
* This is intended to allow for supporting processors which have
* a low power or idle mode. When the IDLE thread is executed, then
* the CPU can be powered down.
*
* The order of precedence for selecting the IDLE thread body is:
*
* -# BSP provided
* -# CPU dependent (if provided)
* -# generic (if no BSP and no CPU dependent)
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_PROVIDES_IDLE_THREAD_BODY TRUE
/**
* 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:
*
* XXX document implementation including references if appropriate
*/
#define CPU_STACK_GROWS_UP FALSE
/* FIXME: Is this the right value? */
#define CPU_CACHE_LINE_BYTES 32
#define CPU_STRUCTURE_ALIGNMENT
/**
* @ingroup CPUInterrupt
* 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:
*
* XXX document implementation including references if appropriate
*/
#define CPU_MODES_INTERRUPT_MASK 0x00000001
#define CPU_MAXIMUM_PROCESSORS 32
/*
* Processor defined structures required for cpukit/score.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
/* may need to put some structures here. */
#ifndef ASM
/**
* @defgroup CPUContext Processor Dependent Context Management
*
* 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:
*
* XXX document implementation including references if appropriate
*/
/**@{**/
/**
* 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.
*/
/* make sure this stays in sync with the assembly function
__CPU_Context_switch in cpu_asm.S */
typedef struct {
uint32_t register_r4;
uint32_t register_r5;
uint32_t register_r6;
uint32_t register_r7;
uint32_t register_p3;
uint32_t register_p4;
uint32_t register_p5;
uint32_t register_fp;
uint32_t register_sp;
uint32_t register_rets;
uint32_t imask;
} Context_Control;
#define _CPU_Context_Get_SP( _context ) \
(_context)->register_sp
/**
* This defines the complete set of floating point registers that must
* be saved during any context switch from one thread to another.
*/
typedef struct {
/* FPU registers are listed here */
/* Blackfin has no Floating Point */
} Context_Control_fp;
/**
* 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 CPUInterrupt Processor Dependent Interrupt Management
*
* On some CPUs, RTEMS supports a software managed interrupt stack.
* This stack is allocated by the Interrupt Manager and the switch
* is performed in @ref _ISR_Handler. These variables contain pointers
* to the lowest and highest addresses in the chunk of memory allocated
* for the interrupt stack. Since it is unknown whether the stack
* grows up or down (in general), this give the CPU dependent
* code the option of picking the version it wants to use.
*
* @note These two variables are required if the macro
* @ref CPU_HAS_SOFTWARE_INTERRUPT_STACK is defined as TRUE.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
/**@{**/
/*
* Nothing prevents the porter from declaring more CPU specific variables.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
/* XXX: if needed, put more variables here */
/**
* @ingroup CPUContext
* The size of the floating point context area. On some CPUs this
* will not be a "sizeof" because the format of the floating point
* area is not defined -- only the size is. This is usually on
* CPUs with a "floating point save context" instruction.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_CONTEXT_FP_SIZE sizeof( Context_Control_fp )
#endif /* ASM */
/**
* 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:
*
* XXX document implementation including references if appropriate
*/
#define CPU_MPCI_RECEIVE_SERVER_EXTRA_STACK 0
/**
* @ingroup CPUInterrupt
* This defines the number of entries in the @ref _ISR_Vector_table managed
* by RTEMS.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_INTERRUPT_NUMBER_OF_VECTORS 16
/**
* @ingroup CPUInterrupt
* This defines the highest interrupt vector number for this port.
*/
#define CPU_INTERRUPT_MAXIMUM_VECTOR_NUMBER (CPU_INTERRUPT_NUMBER_OF_VECTORS - 1)
/**
* @ingroup CPUInterrupt
* 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
/** @} */
/**
* @ingroup CPUContext
* Should be large enough to run all RTEMS tests. This ensures
* that a "reasonable" small application should not have any problems.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_STACK_MINIMUM_SIZE (1024*8)
#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:
*
* XXX document implementation including references if appropriate
*/
#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:
*
* XXX document implementation including references if appropriate
*/
#define CPU_HEAP_ALIGNMENT CPU_ALIGNMENT
/**
* This number corresponds to the byte alignment requirement for memory
* buffers allocated by the partition manager. This alignment requirement
* may be stricter than that for the data types alignment specified by
* @ref CPU_ALIGNMENT. It is common for the partition to follow the same
* alignment requirement as @ref CPU_ALIGNMENT. If the @ref CPU_ALIGNMENT is
* strict enough for the partition, then this should be set to
* @ref CPU_ALIGNMENT.
*
* @note This does not have to be a power of 2. It does have to
* be greater or equal to than @ref CPU_ALIGNMENT.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_PARTITION_ALIGNMENT CPU_ALIGNMENT
/**
* This number corresponds to the byte alignment requirement for the
* stack. This alignment requirement may be stricter than that for the
* data types alignment specified by @ref CPU_ALIGNMENT. If the
* @ref CPU_ALIGNMENT is strict enough for the stack, then this should be
* set to 0.
*
* @note This must be a power of 2 either 0 or greater than @ref CPU_ALIGNMENT.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define CPU_STACK_ALIGNMENT 8
#ifndef ASM
/*
* ISR handler macros
*/
/**
* @addtogroup CPUInterrupt
*/
/**@{**/
/**
* Support routine to initialize the RTEMS vector table after it is allocated.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
#define _CPU_Initialize_vectors()
/**
* 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:
*
* XXX document implementation including references if appropriate
*/
#define _CPU_ISR_Disable( _level ) \
{ \
__asm__ volatile ("cli %0; csync \n" : "=d" (_level) ); \
}
/**
* 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:
*
* XXX document implementation including references if appropriate
*/
#define _CPU_ISR_Enable( _level ) { \
__asm__ __volatile__ ("sti %0; csync \n" : : "d" (_level) ); \
}
/**
* 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:
*
* XXX document implementation including references if appropriate
*/
#define _CPU_ISR_Flash( _level ) { \
__asm__ __volatile__ ("sti %0; csync; cli r0; csync" \
: : "d"(_level) : "R0" ); \
}
RTEMS_INLINE_ROUTINE bool _CPU_ISR_Is_enabled( uint32_t level )
{
return level != 0;
}
/**
* 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:
*
* XXX document implementation including references if appropriate
*/
#define _CPU_ISR_Set_level( _new_level ) \
{ \
__asm__ __volatile__ ( "sti %0; csync" : : "d"(_new_level ? 0 : 0xffff) ); \
}
/**
* 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:
*
* XXX document implementation including references if appropriate
*/
uint32_t _CPU_ISR_Get_level( void );
/* end of ISR handler macros */
/** @} */
/* Context handler macros */
/**
* @ingroup CPUContext
* 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:
*
* See implementation in cpu.c
*/
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:
*
* XXX document implementation including references if appropriate
*/
#define _CPU_Context_Restart_self( _the_context ) \
_CPU_Context_restore( (_the_context) );
#define _CPU_Context_Initialize_fp( _destination ) \
memset( *( _destination ), 0, CPU_CONTEXT_FP_SIZE );
/* 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:
*
* XXX document implementation including references if appropriate
*/
#define _CPU_Fatal_halt( _source, _error ) \
{ \
__asm__ volatile ( "cli R1; \
R1 = %0; \
_halt: \
idle; \
jump _halt;"\
: : "r" (_error) ); \
}
/* end of Fatal Error manager macros */
#define CPU_USE_GENERIC_BITFIELD_CODE TRUE
/* functions */
/**
* @brief CPU initialize.
* This routine performs CPU dependent initialization.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
void _CPU_Initialize(void);
/**
* @ingroup CPUInterrupt
* This routine installs a "raw" interrupt handler directly into the
* processor's vector table.
*
* @param[in] vector is the vector number
* @param[in] new_handler is the raw ISR handler to install
* @param[in] old_handler is the previously installed ISR Handler
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
void _CPU_ISR_install_raw_handler(
uint32_t vector,
proc_ptr new_handler,
proc_ptr *old_handler
);
/**
* @ingroup CPUInterrupt
* This routine installs an interrupt vector.
*
* @param[in] vector is the vector number
* @param[in] new_handler is the RTEMS ISR handler to install
* @param[in] old_handler is the previously installed ISR Handler
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
void _CPU_ISR_install_vector(
uint32_t vector,
proc_ptr new_handler,
proc_ptr *old_handler
);
/**
* @ingroup CPUInterrupt
* This routine installs the hardware interrupt stack pointer.
*
* @note It need only be provided if @ref CPU_HAS_HARDWARE_INTERRUPT_STACK
* is TRUE.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
void _CPU_Install_interrupt_stack( void );
/**
* This routine is the CPU dependent IDLE thread body.
*
* @note It need only be provided if @ref CPU_PROVIDES_IDLE_THREAD_BODY
* is TRUE.
*
* Port Specific Information:
*
* XXX document implementation including references if appropriate
*/
void *_CPU_Thread_Idle_body( uintptr_t ignored );
/**
* @addtogroup CPUContext
*/
/**@{**/
/**
* 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:
*
* XXX document implementation including references if appropriate
*/
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:
*
* XXX document implementation including references if appropriate
*/
void _CPU_Context_restore(
Context_Control *new_context
) RTEMS_NO_RETURN;
/**
* 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
);
/**
* 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
);
static inline void _CPU_Context_volatile_clobber( uintptr_t pattern )
{
/* TODO */
}
static inline void _CPU_Context_validate( uintptr_t pattern )
{
while (1) {
/* TODO */
}
}
/** @} */
/* FIXME */
typedef CPU_Interrupt_frame CPU_Exception_frame;
void _CPU_Exception_frame_print( const CPU_Exception_frame *frame );
/**
* @ingroup 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:
*
* XXX document implementation including references if appropriate
*/
static inline uint32_t CPU_swap_u32(
uint32_t value
)
{
uint32_t byte1, byte2, byte3, byte4, swapped;
byte4 = (value >> 24) & 0xff;
byte3 = (value >> 16) & 0xff;
byte2 = (value >> 8) & 0xff;
byte1 = value & 0xff;
swapped = (byte1 << 24) | (byte2 << 16) | (byte3 << 8) | byte4;
return( swapped );
}
/**
* @ingroup CPUEndian
* This routine swaps a 16 bir quantity.
*
* @param[in] value is the value to be swapped
* @return the value after being endian swapped
*/
#define CPU_swap_u16( value ) \
(((value&0xff) << 8) | ((value >> 8)&0xff))
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;
#endif /* ASM */
#ifdef __cplusplus
}
#endif
#endif
