/**
* @file rtems/score/cpu.h
*/
/*
* This include file contains information pertaining to the Moxie
* processor.
*
* Copyright (c) 2013 Anthony Green
*
* Based on code with the following copyright..
* COPYRIGHT (c) 1989-2006, 2010.
* 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/types.h>
#include <rtems/score/moxie.h> /* pick up machine definitions */
#include <rtems/bspIo.h> /* printk */
/* conditional compilation parameters */
/*
* Should this target use 16 or 32 bit object Ids?
*
*/
#define RTEMS_USE_32_BIT_OBJECT
/*
* Does RTEMS manage a dedicated interrupt stack in software?
*
* If TRUE, then a stack is allocated in _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, CPU_ALLOCATE_INTERRUPT_STACK should also be TRUE.
*
* Only one of CPU_HAS_SOFTWARE_INTERRUPT_STACK and
* 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.
*
* MOXIE Specific Information:
*
* XXX
*/
#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
*
* MOXIE 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, CPU_ALLOCATE_INTERRUPT_STACK should also be TRUE.
*
* Only one of CPU_HAS_SOFTWARE_INTERRUPT_STACK and
* 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.
*
* MOXIE Specific Information:
*
* XXX
*/
#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.
*
* MOXIE Specific Information:
*
* XXX
*/
#define CPU_ALLOCATE_INTERRUPT_STACK TRUE
/*
* 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 "MOXIE_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.
*
* MOXIE Specific Information:
*
* XXX
*/
#define CPU_HARDWARE_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.
*
* If CPU_HARDWARE_FP is FALSE, then this should be FALSE as well.
*
* MOXIE Specific Information:
*
* XXX
*/
#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.
*
* MOXIE Specific Information:
*
* XXX
*/
#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.
*
* MOXIE Specific Information:
*
* XXX
*/
#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 _CPU_Internal_threads_Idle_thread_body
* must be provided and is the default IDLE thread body instead of
* _Internal_threads_Idle_thread_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:
*
* 1. BSP provided
* 2. CPU dependent (if provided)
* 3. generic (if no BSP and no CPU dependent)
*
* MOXIE Specific Information:
*
* XXX
* The port initially called a BSP dependent routine called
* IDLE_Monitor. The idle task body can be overridden by
* the BSP in newer versions of RTEMS.
*/
#define CPU_PROVIDES_IDLE_THREAD_BODY 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.
*
* MOXIE Specific Information:
*
* XXX
*/
#define CPU_STACK_GROWS_UP FALSE
/* FIXME: Is this the right value? */
#define CPU_CACHE_LINE_BYTES 32
#define CPU_STRUCTURE_ALIGNMENT
/*
* Define what is required to specify how the network to host conversion
* routines are handled.
*/
#define CPU_BIG_ENDIAN TRUE
#define CPU_LITTLE_ENDIAN FALSE
/*
* 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 _CPU_ISR_Set_level().
*
* MOXIE Specific Information:
*
* XXX
*/
#define CPU_MODES_INTERRUPT_MASK 0x00000001
#define CPU_MAXIMUM_PROCESSORS 32
/*
* Processor defined structures required for cpukit/score.
*
* MOXIE Specific Information:
*
* XXX
*/
/* may need to put some structures here. */
/*
* Contexts
*
* Generally there are 2 types of context to save.
* 1. Interrupt registers to save
* 2. Task level registers to save
*
* This means we have the following 3 context items:
* 1. task level context stuff:: Context_Control
* 2. floating point task stuff:: Context_Control_fp
* 3. special interrupt level context :: Context_Control_interrupt
*
* 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.
*
* MOXIE Specific Information:
*
* XXX
*/
#define nogap __attribute__ ((packed))
typedef struct {
void *fp nogap;
void *sp nogap;
uint32_t r0 nogap;
uint32_t r1 nogap;
uint32_t r2 nogap;
uint32_t r3 nogap;
uint32_t r4 nogap;
uint32_t r5 nogap;
uint32_t r6 nogap;
uint32_t r7 nogap;
uint32_t r8 nogap;
uint32_t r9 nogap;
uint32_t r10 nogap;
uint32_t r11 nogap;
uint32_t r12 nogap;
uint32_t r13 nogap;
} Context_Control;
#define _CPU_Context_Get_SP( _context ) \
(_context)->sp
typedef struct {
double some_float_register[2];
} Context_Control_fp;
typedef struct {
uint32_t special_interrupt_register;
} CPU_Interrupt_frame;
/*
* Nothing prevents the porter from declaring more CPU specific variables.
*
* MOXIE Specific Information:
*
* XXX
*/
/*
* 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.
*
* MOXIE Specific Information:
*
* XXX
*/
#define CPU_CONTEXT_FP_SIZE sizeof( Context_Control_fp )
/*
* Amount of extra stack (above minimum stack size) required by
* system initialization thread. Remember that in a multiprocessor
* system the system intialization thread becomes the MP server thread.
*
* MOXIE Specific Information:
*
* It is highly unlikely the MOXIE will get used in a multiprocessor system.
*/
#define CPU_MPCI_RECEIVE_SERVER_EXTRA_STACK 0
/*
* This defines the number of entries in the ISR_Vector_table managed
* by RTEMS.
*
* MOXIE Specific Information:
*
* XXX
*/
#define CPU_INTERRUPT_NUMBER_OF_VECTORS 64
#define CPU_INTERRUPT_MAXIMUM_VECTOR_NUMBER \
(CPU_INTERRUPT_NUMBER_OF_VECTORS - 1)
/*
* This is defined if the port has a special way to report the ISR nesting
* level. Most ports maintain the variable _ISR_Nest_level.
*/
#define CPU_PROVIDES_ISR_IS_IN_PROGRESS FALSE
/*
* Should be large enough to run all RTEMS tests. This ensures
* that a "reasonable" small application should not have any problems.
*
* MOXIE Specific Information:
*
* XXX
*/
#define CPU_STACK_MINIMUM_SIZE (1536)
/**
* Size of a pointer.
*
* This must be an integer literal that can be used by the assembler. This
* value will be used to calculate offsets of structure members. These
* offsets will be used in assembler code.
*/
#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.
*
* MOXIE Specific Information:
*
* XXX
*/
#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 CPU_ALIGNMENT. It is
* common for the heap to follow the same alignment requirement as
* CPU_ALIGNMENT. If the CPU_ALIGNMENT is strict enough for the heap,
* then this should be set to CPU_ALIGNMENT.
*
* NOTE: This does not have to be a power of 2. It does have to
* be greater or equal to than CPU_ALIGNMENT.
*
* MOXIE Specific Information:
*
* XXX
*/
#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
* CPU_ALIGNMENT. It is common for the partition to follow the same
* alignment requirement as CPU_ALIGNMENT. If the CPU_ALIGNMENT is strict
* enough for the partition, then this should be set to CPU_ALIGNMENT.
*
* NOTE: This does not have to be a power of 2. It does have to
* be greater or equal to than CPU_ALIGNMENT.
*
* MOXIE Specific Information:
*
* XXX
*/
#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 CPU_ALIGNMENT. If the 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 CPU_ALIGNMENT.
*
* MOXIE Specific Information:
*
* XXX
*/
#define CPU_STACK_ALIGNMENT 0
/*
* ISR handler macros
*/
/*
* Support routine to initialize the RTEMS vector table after it is allocated.
*/
#define _CPU_Initialize_vectors()
/*
* Disable all interrupts for an RTEMS critical section. The previous
* level is returned in _level.
*
* MOXIE Specific Information:
*
* TODO: As of 7 October 2014, this method is not implemented.
*/
#define _CPU_ISR_Disable( _isr_cookie ) \
do { \
(_isr_cookie) = 0; \
} while (0)
/*
* Enable interrupts to the previous level (returned by _CPU_ISR_Disable).
* This indicates the end of an RTEMS critical section. The parameter
* _level is not modified.
*
* MOXIE Specific Information:
*
* TODO: As of 7 October 2014, this method is not implemented.
*/
#define _CPU_ISR_Enable( _isr_cookie ) \
do { \
(_isr_cookie) = (_isr_cookie); \
} while (0)
/*
* This temporarily restores the interrupt to _level before immediately
* disabling them again. This is used to divide long RTEMS critical
* sections into two or more parts. The parameter _level is not
* modified.
*
* MOXIE Specific Information:
*
* TODO: As of 7 October 2014, this method is not implemented.
*/
#define _CPU_ISR_Flash( _isr_cookie ) \
do { \
_CPU_ISR_Enable( _isr_cookie ); \
_CPU_ISR_Disable( _isr_cookie ); \
} while (0)
RTEMS_INLINE_ROUTINE bool _CPU_ISR_Is_enabled( uint32_t level )
{
return true;
}
/*
* Map 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.
*
* MOXIE Specific Information:
*
* TODO: As of 7 October 2014, this method is not implemented.
*/
#define _CPU_ISR_Set_level( _new_level ) \
{ \
if (_new_level) asm volatile ( "nop\n" ); \
else asm volatile ( "nop\n" ); \
}
uint32_t _CPU_ISR_Get_level( void );
/* end of ISR handler macros */
/* Context handler macros */
/*
* 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.
*
* NOTE: This is_fp parameter 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.
*
* MOXIE Specific Information:
*
* TODO: As of 7 October 2014, this method does not ensure that the context
* is set up with interrupts disabled/enabled as requested.
*/
#define CPU_CCR_INTERRUPTS_ON 0x80
#define CPU_CCR_INTERRUPTS_OFF 0x00
#define _CPU_Context_Initialize( _the_context, _stack_base, _size, \
_isr, _entry_point, _is_fp, _tls_area ) \
/* Locate Me */ \
do { \
uintptr_t _stack; \
\
(void) _is_fp; /* avoid warning for being unused */ \
(void) _isr; /* avoid warning for being unused */ \
_stack = ((uintptr_t)(_stack_base)) + (_size) - 8; \
*((proc_ptr *)(_stack)) = (_entry_point); \
_stack -= 4; \
(_the_context)->fp = (void *)_stack; \
(_the_context)->sp = (void *)_stack; \
} while (0)
/*
* 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. Context_Restore should work most of the time. It will
* not work if restarting self conflicts with the stack frame
* assumptions of restoring a context.
*
* MOXIE Specific Information:
*
* XXX
*/
#define _CPU_Context_Restart_self( _the_context ) \
_CPU_Context_restore( (_the_context) );
/*
* The purpose of this macro is to allow the initial pointer into
* a floating point context area (used to save the floating point
* context) to be at an arbitrary place in the floating point
* context area.
*
* This is necessary because some FP units are designed to have
* their context saved as a stack which grows into lower addresses.
* Other FP units can be saved by simply moving registers into offsets
* from the base of the context area. Finally some FP units provide
* a "dump context" instruction which could fill in from high to low
* or low to high based on the whim of the CPU designers.
*
* MOXIE Specific Information:
*
* XXX
*/
#define _CPU_Context_Fp_start( _base, _offset ) \
( (void *) (_base) + (_offset) )
#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.
*
* MOXIE Specific Information:
*
* XXX
*/
#define _CPU_Fatal_halt( _source, _error ) \
printk("Fatal Error %d.%d Halted\n",_source,_error); \
for(;;)
/* end of Fatal Error manager macros */
#define CPU_USE_GENERIC_BITFIELD_CODE TRUE
/* functions */
/*
* _CPU_Initialize
*
* This routine performs CPU dependent initialization.
*
* MOXIE Specific Information:
*
* XXX
*/
void _CPU_Initialize(void);
/*
* _CPU_ISR_install_raw_handler
*
* This routine installs a "raw" interrupt handler directly into the
* processor's vector table.
*
* MOXIE Specific Information:
*
* XXX
*/
void _CPU_ISR_install_raw_handler(
uint32_t vector,
proc_ptr new_handler,
proc_ptr *old_handler
);
/*
* _CPU_ISR_install_vector
*
* This routine installs an interrupt vector.
*
* MOXIE Specific Information:
*
* XXX
*/
void _CPU_ISR_install_vector(
uint32_t vector,
proc_ptr new_handler,
proc_ptr *old_handler
);
/*
* _CPU_Install_interrupt_stack
*
* This routine installs the hardware interrupt stack pointer.
*
* NOTE: It need only be provided if CPU_HAS_HARDWARE_INTERRUPT_STACK
* is TRUE.
*
* MOXIE Specific Information:
*
* XXX
*/
void _CPU_Install_interrupt_stack( void );
/*
* _CPU_Internal_threads_Idle_thread_body
*
* This routine is the CPU dependent IDLE thread body.
*
* NOTE: It need only be provided if CPU_PROVIDES_IDLE_THREAD_BODY
* is TRUE.
*
* MOXIE Specific Information:
*
* XXX
*/
void *_CPU_Thread_Idle_body( uint32_t );
/*
* _CPU_Context_switch
*
* This routine switches from the run context to the heir context.
*
* MOXIE Specific Information:
*
* XXX
*/
void _CPU_Context_switch(
Context_Control *run,
Context_Control *heir
);
/*
* _CPU_Context_restore
*
* This routine is generallu 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.
*
* MOXIE Specific Information:
*
* XXX
*/
void _CPU_Context_restore(
Context_Control *new_context
) RTEMS_NO_RETURN;
/*
* _CPU_Context_save_fp
*
* This routine saves the floating point context passed to it.
*
* MOXIE Specific Information:
*
* XXX
*/
void _CPU_Context_save_fp(
Context_Control_fp **fp_context_ptr
);
/*
* _CPU_Context_restore_fp
*
* This routine restores the floating point context passed to it.
*
* MOXIE Specific Information:
*
* XXX
*/
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 */
}
}
/**
* @brief The set of registers that specifies the complete processor state.
*
* The CPU exception frame may be available in fatal error conditions like for
* example illegal opcodes, instruction fetch errors, or data access errors.
*
* @see rtems_fatal(), RTEMS_FATAL_SOURCE_EXCEPTION, and
* rtems_exception_frame_print().
*/
typedef struct {
uint32_t integer_registers [16];
} CPU_Exception_frame;
/**
* @brief Prints the exception frame via printk().
*
* @see rtems_fatal() and RTEMS_FATAL_SOURCE_EXCEPTION.
*/
void _CPU_Exception_frame_print( const CPU_Exception_frame *frame );
/* 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.
*
* MOXIE Specific Information:
*
* This is the generic implementation.
*/
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 );
}
#define CPU_swap_u16( value ) \
(((value&0xff) << 8) | ((value >> 8)&0xff))
typedef uint32_t CPU_Counter_ticks;
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;
}
#ifdef __cplusplus
}
#endif
#endif
