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Diffstat (limited to 'cpukit/score/cpu/m32c/rtems/score/cpu.h')
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diff --git a/cpukit/score/cpu/m32c/rtems/score/cpu.h b/cpukit/score/cpu/m32c/rtems/score/cpu.h new file mode 100644 index 0000000000..4d75c0a930 --- /dev/null +++ b/cpukit/score/cpu/m32c/rtems/score/cpu.h @@ -0,0 +1,1186 @@ +/** + * @file rtems/score/cpu.h + */ + +/* + * This include file contains information pertaining to the XXX + * processor. + * + * @note This file is part of a porting template that is intended + * to be used as the starting point when porting RTEMS to a new + * CPU family. The following needs to be done when using this as + * the starting point for a new port: + * + * + Anywhere there is an XXX, it should be replaced + * with information about the CPU family being ported to. + * + * + At the end of each comment section, there is a heading which + * says "Port Specific Information:". When porting to RTEMS, + * add CPU family specific information in this section + */ + +/* + * COPYRIGHT (c) 1989-2008. + * 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.com/license/LICENSE. + * + * $Id$ + */ + +#ifndef _RTEMS_SCORE_CPU_H +#define _RTEMS_SCORE_CPU_H + +#ifdef __cplusplus +extern "C" { +#endif + +#include <rtems/score/types.h> +#include <rtems/score/m32c.h> + +/* conditional compilation parameters */ + +#define RTEMS_USE_16_BIT_OBJECT + +/** + * Should the calls to @ref _Thread_Enable_dispatch be inlined? + * + * If TRUE, then they are inlined. + * If FALSE, then a subroutine call is made. + * + * This conditional is an example of the classic trade-off of size + * versus speed. Inlining the call (TRUE) typically increases the + * size of RTEMS while speeding up the enabling of dispatching. + * + * @note In general, the @ref _Thread_Dispatch_disable_level will + * only be 0 or 1 unless you are in an interrupt handler and that + * interrupt handler invokes the executive.] When not inlined + * something calls @ref _Thread_Enable_dispatch which in turns calls + * @ref _Thread_Dispatch. If the enable dispatch is inlined, then + * one subroutine call is avoided entirely. + * + * Port Specific Information: + * + * XXX document implementation including references if appropriate + */ +#define CPU_INLINE_ENABLE_DISPATCH FALSE + +/** + * Should the body of the search loops in _Thread_queue_Enqueue_priority + * be unrolled one time? In unrolled each iteration of the loop examines + * two "nodes" on the chain being searched. Otherwise, only one node + * is examined per iteration. + * + * If TRUE, then the loops are unrolled. + * If FALSE, then the loops are not unrolled. + * + * The primary factor in making this decision is the cost of disabling + * and enabling interrupts (_ISR_Flash) versus the cost of rest of the + * body of the loop. On some CPUs, the flash is more expensive than + * one iteration of the loop body. In this case, it might be desirable + * to unroll the loop. It is important to note that on some CPUs, this + * code is the longest interrupt disable period in RTEMS. So it is + * necessary to strike a balance when setting this parameter. + * + * Port Specific Information: + * + * XXX document implementation including references if appropriate + */ +#define CPU_UNROLL_ENQUEUE_PRIORITY TRUE + +/** + * 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 FALSE + +/** + * 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: + * + * 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 TRUE + +/** + * 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 0 + +/** + * @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 "M32C_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 ( M32C_HAS_FPU == 1 ) +#define CPU_HARDWARE_FP TRUE +#else +#define CPU_HARDWARE_FP FALSE +#endif +#define CPU_SOFTWARE_FP FALSE + +#define CPU_CONTEXT_FP_SIZE 0 + +/** + * 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 TRUE + +/** + * 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 + +/** + * 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 TRUE + +/** + * The following is the variable attribute used to force alignment + * of critical RTEMS structures. On some processors it may make + * sense to have these aligned on tighter boundaries than + * the minimum requirements of the compiler in order to have as + * much of the critical data area as possible in a cache line. + * + * The placement of this macro in the declaration of the variables + * is based on the syntactically requirements of the GNU C + * "__attribute__" extension. For example with GNU C, use + * the following to force a structures to a 32 byte boundary. + * + * __attribute__ ((aligned (32))) + * + * @note Currently only the Priority Bit Map table uses this feature. + * To benefit from using this, the data must be heavily + * used so it will stay in the cache and used frequently enough + * in the executive to justify turning this on. + * + * Port Specific Information: + * + * XXX document implementation including references if appropriate + */ +#define CPU_STRUCTURE_ALIGNMENT __attribute__ ((aligned (2))) + + +/** + * @defgroup CPUEndian Processor Dependent Endianness Support + * + * This group assists in issues related to processor endianness. + */ + +/** + * @ingroup CPUEndian + * Define what is required to specify how the network to host conversion + * routines are handled. + * + * @note @a CPU_BIG_ENDIAN and @a CPU_LITTLE_ENDIAN should NOT have the + * same values. + * + * @see CPU_LITTLE_ENDIAN + * + * Port Specific Information: + * + * XXX document implementation including references if appropriate + */ +#define CPU_BIG_ENDIAN TRUE + +/** + * @ingroup CPUEndian + * Define what is required to specify how the network to host conversion + * routines are handled. + * + * @note @ref CPU_BIG_ENDIAN and @ref CPU_LITTLE_ENDIAN should NOT have the + * same values. + * + * @see CPU_BIG_ENDIAN + * + * Port Specific Information: + * + * XXX document implementation including references if appropriate + */ +#define CPU_LITTLE_ENDIAN FALSE + +/** + * @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 + +/* + * Processor defined structures required for cpukit/score. + * + * Port Specific Information: + * + * XXX document implementation including references if appropriate + */ + +/* may need to put some structures here. */ + +/** + * @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 + */ + +/** + * @ingroup CPUContext Management + * 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 { + /** This will contain the stack pointer. */ + uint32_t sp; + /** This will contain the frame base pointer. */ + uint32_t fb; +} Context_Control; + +/** + * @ingroup CPUContext Management + * + * 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)->sp + +/** + * @ingroup CPUContext Management + * 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 */ + +/** + * 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 32 + +/** + * @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 (2048L) + +/** + * 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 2 + +/** + * 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 4 + +/** + * 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 0 + +/* + * ISR handler macros + */ + +/** + * @ingroup 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() + +/** + * @ingroup CPUInterrupt + * 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( _isr_cookie ) \ + do { \ + int _flg; \ + m32c_get_flg( _flg ); \ + _isr_cookie = _flg; \ + __asm__ volatile( "fclr I" ); \ + } while(0) + +/** + * @ingroup CPUInterrupt + * 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(_isr_cookie) \ + do { \ + int _flg = (int) (_isr_cookie); \ + m32c_set_flg( _flg ); \ + } while(0) + +/** + * @ingroup CPUInterrupt + * 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( _isr_cookie ) \ + do { \ + int _flg = (int) (_isr_cookie); \ + m32c_set_flg( _flg ); \ + __asm__ volatile( "fclr I" ); \ + } while(0) + +/** + * @ingroup CPUInterrupt + * + * 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 ) \ + do { \ + if (_new_level) __asm__ volatile( "fclr I" ); \ + else __asm__ volatile( "fset I" ); \ + } while(0) + +/** + * @ingroup CPUInterrupt + * 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. + * + * Port Specific Information: + * + * XXX document implementation including references if appropriate + */ +void _CPU_Context_Initialize( + Context_Control *the_context, + uint32_t *stack_base, + size_t size, + uint32_t new_level, + void *entry_point, + bool is_fp +); + +/** + * 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 + */ +void _CPU_Context_Restart_self( + Context_Control *the_context +); + +/** + * @ingroup CPUContext + * 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. + * + * @param[in] _base is the lowest physical address of the floating point + * context area + * @param[in] _offset is the offset into the floating point area + * + * Port Specific Information: + * + * XXX document implementation including references if appropriate + */ +#define _CPU_Context_Fp_start( _base, _offset ) \ + ( (void *) _Addresses_Add_offset( (_base), (_offset) ) ) + +/** + * 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 ) \ + { \ + *(*(_destination)) = _CPU_Null_fp_context; \ + } + +/* 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( _error ) \ + { \ + } + +/* end of Fatal Error manager macros */ + +/* Bitfield handler macros */ + +/** + * @defgroup CPUBitfield Processor Dependent Bitfield Manipulation + * + * This set of routines are used to implement fast searches for + * the most important ready task. + */ + +/** + * @ingroup CPUBitfield + * This definition is set to TRUE if the port uses the generic bitfield + * manipulation implementation. + */ +#define CPU_USE_GENERIC_BITFIELD_CODE TRUE + +/** + * @ingroup CPUBitfield + * This definition is set to TRUE if the port uses the data tables provided + * by the generic bitfield manipulation implementation. + * This can occur when actually using the generic bitfield manipulation + * implementation or when implementing the same algorithm in assembly + * language for improved performance. It is unlikely that a port will use + * the data if it has a bitfield scan instruction. + */ +#define CPU_USE_GENERIC_BITFIELD_DATA TRUE + +/** + * @ingroup CPUBitfield + * This routine sets @a _output to the bit number of the first bit + * set in @a _value. @a _value is of CPU dependent type + * @a Priority_bit_map_Control. This type may be either 16 or 32 bits + * wide although only the 16 least significant bits will be used. + * + * There are a number of variables in using a "find first bit" type + * instruction. + * + * -# What happens when run on a value of zero? + * -# Bits may be numbered from MSB to LSB or vice-versa. + * -# The numbering may be zero or one based. + * -# The "find first bit" instruction may search from MSB or LSB. + * + * RTEMS guarantees that (1) will never happen so it is not a concern. + * (2),(3), (4) are handled by the macros @ref _CPU_Priority_Mask and + * @ref _CPU_Priority_bits_index. These three form a set of routines + * which must logically operate together. Bits in the _value are + * set and cleared based on masks built by @ref _CPU_Priority_Mask. + * The basic major and minor values calculated by @ref _Priority_Major + * and @ref _Priority_Minor are "massaged" by @ref _CPU_Priority_bits_index + * to properly range between the values returned by the "find first bit" + * instruction. This makes it possible for @ref _Priority_Get_highest to + * calculate the major and directly index into the minor table. + * This mapping is necessary to ensure that 0 (a high priority major/minor) + * is the first bit found. + * + * This entire "find first bit" and mapping process depends heavily + * on the manner in which a priority is broken into a major and minor + * components with the major being the 4 MSB of a priority and minor + * the 4 LSB. Thus (0 << 4) + 0 corresponds to priority 0 -- the highest + * priority. And (15 << 4) + 14 corresponds to priority 254 -- the next + * to the lowest priority. + * + * If your CPU does not have a "find first bit" instruction, then + * there are ways to make do without it. Here are a handful of ways + * to implement this in software: + * +@verbatim + - a series of 16 bit test instructions + - a "binary search using if's" + - _number = 0 + if _value > 0x00ff + _value >>=8 + _number = 8; + + if _value > 0x0000f + _value >=8 + _number += 4 + + _number += bit_set_table[ _value ] +@endverbatim + + * where bit_set_table[ 16 ] has values which indicate the first + * bit set + * + * @param[in] _value is the value to be scanned + * @param[in] _output is the first bit set + * + * Port Specific Information: + * + * XXX document implementation including references if appropriate + */ + +#if (CPU_USE_GENERIC_BITFIELD_CODE == FALSE) +#define _CPU_Bitfield_Find_first_bit( _value, _output ) \ + { \ + (_output) = 0; /* do something to prevent warnings */ \ + } +#endif + +/* end of Bitfield handler macros */ + +/** + * This routine builds the mask which corresponds to the bit fields + * as searched by @ref _CPU_Bitfield_Find_first_bit. See the discussion + * for that routine. + * + * Port Specific Information: + * + * XXX document implementation including references if appropriate + */ +#if (CPU_USE_GENERIC_BITFIELD_CODE == FALSE) + +#define _CPU_Priority_Mask( _bit_number ) \ + ( 1 << (_bit_number) ) + +#endif + +/** + * @ingroup CPUBitfield + * This routine translates the bit numbers returned by + * @ref _CPU_Bitfield_Find_first_bit into something suitable for use as + * a major or minor component of a priority. See the discussion + * for that routine. + * + * @param[in] _priority is the major or minor number to translate + * + * Port Specific Information: + * + * XXX document implementation including references if appropriate + */ +#if (CPU_USE_GENERIC_BITFIELD_CODE == FALSE) + +#define _CPU_Priority_bits_index( _priority ) \ + (_priority) + +#endif + +/* end of Priority handler macros */ + +/* functions */ + +/** + * 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 ); + +/** + * @ingroup 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 +); + +/** + * @ingroup CPUContext + * 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_COMPILER_NO_RETURN_ATTRIBUTE; + +/** + * @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)) + +#ifdef __cplusplus +} +#endif + +#endif |