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Diffstat (limited to 'include/rtems/score/context.h')
| -rw-r--r-- | include/rtems/score/context.h | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/include/rtems/score/context.h b/include/rtems/score/context.h new file mode 100644 index 0000000000..7e59f05d60 --- /dev/null +++ b/include/rtems/score/context.h @@ -0,0 +1,172 @@ +/** + * @file rtems/score/context.h + * + * @brief Information About Each Thread's Context + * + * This include file contains all information about each thread's context. + */ + +/* + * COPYRIGHT (c) 1989-2011. + * 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_CONTEXT_H +#define _RTEMS_SCORE_CONTEXT_H + +/** + * @defgroup ScoreContext Context Handler + * + * @ingroup Score + * + * This handler encapsulates functionality which abstracts thread context + * management in a portable manner. + * + * The context switch needed variable is contained in the per cpu + * data structure. + */ +/**@{*/ + +#ifdef __cplusplus +extern "C" { +#endif + +#include <rtems/score/cpu.h> + +/** + * @brief Size of floating point context area. + * + * This constant defines the number of bytes required + * to store a full floating point context. + */ +#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE ) + #define CONTEXT_FP_SIZE CPU_CONTEXT_FP_SIZE +#else + #define CONTEXT_FP_SIZE 0 +#endif + +/** + * @brief Initialize context area. + * + * This routine initializes @a _the_context such that the stack + * pointer, interrupt level, and entry point are correct for the + * thread's initial state. + * + * @param[in] _the_context will be initialized + * @param[in] _stack is the lowest physical address of the thread's + * context + * @param[in] _size is the size in octets of the thread's context + * @param[in] _isr is the ISR enable level for this thread + * @param[in] _entry is this thread's entry point + * @param[in] _is_fp is set to true if this thread has floating point + * enabled + * @param[in] _tls_area The thread-local storage (TLS) area begin. + */ +#define _Context_Initialize( _the_context, _stack, _size, _isr, _entry, \ + _is_fp, _tls_area ) \ + _CPU_Context_Initialize( _the_context, _stack, _size, _isr, _entry, \ + _is_fp, _tls_area ) + +/** + * This macro is invoked from _Thread_Handler to do whatever CPU + * specific magic is required that must be done in the context of + * the thread when it starts. + * + * If the CPU architecture does not require any magic, then this + * macro is empty. + */ + +#if defined(_CPU_Context_Initialization_at_thread_begin) + #define _Context_Initialization_at_thread_begin() \ + _CPU_Context_Initialization_at_thread_begin() +#else + #define _Context_Initialization_at_thread_begin() +#endif + +/** + * @brief Perform context switch. + * + * This routine saves the current context into the @a _executing + * context record and restores the context specified by @a _heir. + * + * @param[in] _executing is the currently executing thread's context + * @param[in] _heir is the context of the thread to be switched to + */ +#define _Context_Switch( _executing, _heir ) \ + _CPU_Context_switch( _executing, _heir ) + +/** + * @brief Restart currently executing thread. + * + * This routine restarts the calling thread by restoring its initial + * stack pointer and returning to the thread's entry point. + * + * @param[in] _the_context is the context of the thread to restart + */ +#define _Context_Restart_self( _the_context ) \ + _CPU_Context_Restart_self( _the_context ) + +/** + * @brief Return starting address of floating point context. + * + * This function returns the starting address of the floating + * point context save area. It is assumed that the are reserved + * for the floating point save area is large enough. + * + * @param[in] _base is lowest physical address of the floating point + * context save area. + * @param[in] _offset is the offset into the floating point area + * + * @retval the initial FP context pointer + */ +#define _Context_Fp_start( _base, _offset ) \ + _CPU_Context_Fp_start( (_base), (_offset) ) + +/** + * @brief Initialize floating point context area. + * + * This routine initializes the floating point context save + * area to contain an initial known state. + * + * @param[in] _fp_area is the base address of the floating point + * context save area to initialize. + */ +#define _Context_Initialize_fp( _fp_area ) \ + _CPU_Context_Initialize_fp( _fp_area ) + +/** + * @brief Restore floating point context area. + * + * This routine restores the floating point context contained + * in the @a _fp area. It is assumed that the current + * floating point context has been saved by a previous invocation + * of @a _Context_Save_fp. + * + * @param[in] _fp points to the floating point context area to restore. + */ +#define _Context_Restore_fp( _fp ) \ + _CPU_Context_restore_fp( _fp ) + +/** + * @brief Save floating point context area. + * + * This routine saves the current floating point context + * in the @a _fp area. + * + * @param[in] _fp points to the floating point context area to restore. + */ +#define _Context_Save_fp( _fp ) \ + _CPU_Context_save_fp( _fp ) + +#ifdef __cplusplus +} +#endif + +/**@}*/ + +#endif +/* end of include file */ |