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Diffstat (limited to 'arch/xtensa/include/xtensa_rtos.h')
| -rw-r--r-- | arch/xtensa/include/xtensa_rtos.h | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/arch/xtensa/include/xtensa_rtos.h b/arch/xtensa/include/xtensa_rtos.h new file mode 100644 index 000000000..7ab549abc --- /dev/null +++ b/arch/xtensa/include/xtensa_rtos.h @@ -0,0 +1,228 @@ +/* + * Copyright (c) 2016 Cadence Design Systems, Inc. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/******************************************************************************* + + RTOS-SPECIFIC INFORMATION FOR XTENSA RTOS ASSEMBLER SOURCES + (FreeRTOS Port) + +This header is the primary glue between generic Xtensa RTOS support +sources and a specific RTOS port for Xtensa. It contains definitions +and macros for use primarily by Xtensa assembly coded source files. + +Macros in this header map callouts from generic Xtensa files to specific +RTOS functions. It may also be included in C source files. + +Xtensa RTOS ports support all RTOS-compatible configurations of the Xtensa +architecture, using the Xtensa hardware abstraction layer (HAL) to deal +with configuration specifics. + +Should be included by all Xtensa generic and RTOS port-specific sources. + +*******************************************************************************/ + +#ifndef XTENSA_RTOS_H +#define XTENSA_RTOS_H + +#ifdef __ASSEMBLER__ +#include <xtensa/coreasm.h> +#else +#include <xtensa/config/core.h> +#endif + +#include <xtensa/corebits.h> +#include <xtensa/config/system.h> +#include <xtensa/simcall.h> + + +/* +Convert FreeRTOSConfig definitions to XTENSA definitions. +However these can still be overridden from the command line. +*/ + +#ifndef XT_SIMULATOR + #if CONFIG_SIMULATOR_XTENSA + #define XT_SIMULATOR 1 /* Simulator mode */ + #endif +#endif + +#ifndef XT_BOARD + #if CONFIG_BOARD_XTENSA + #define XT_BOARD 1 /* Board mode */ + #endif +#endif + +#ifndef XT_TIMER_INDEX + #if defined configXT_TIMER_INDEX + #define XT_TIMER_INDEX configXT_TIMER_INDEX /* Index of hardware timer to be used */ + #endif +#endif + +#ifndef XT_INTEXC_HOOKS + #if configXT_INTEXC_HOOKS + #define XT_INTEXC_HOOKS 1 /* Enables exception hooks */ + #endif +#endif + +#if (!XT_SIMULATOR) && (!XT_BOARD) + #error Either XT_SIMULATOR or XT_BOARD must be defined. +#endif + + +/* +Name of RTOS (for messages). +*/ +#define XT_RTOS_NAME Zephyr + +/* + * Define for enabling RTOS specific code. Enable only one of below lines. + */ +#define XT_RTOS_IS_ZEPHYR_OS 1 +#undef XT_RTOS_IS_FREE_RTOS + +/* +Check some Xtensa configuration requirements and report error if not met. +Error messages can be customize to the RTOS port. +*/ + +#if !XCHAL_HAVE_XEA2 +#error "Zephyr/Xtensa requires XEA2 (exception architecture 2)." +#endif + +/******************************************************************************* + +RTOS CALLOUT MACROS MAPPED TO RTOS PORT-SPECIFIC FUNCTIONS. + +Define callout macros used in generic Xtensa code to interact with the RTOS. +The macros are simply the function names for use in calls from assembler code. +Some of these functions may call back to generic functions in xtensa_context.h . + +*******************************************************************************/ + +/* +Inform RTOS of entry into an interrupt handler that will affect it. +Allows RTOS to manage switch to any system stack and count nesting level. +Called after minimal context has been saved, with interrupts disabled. +RTOS port can call0 _xt_context_save to save the rest of the context. +May only be called from assembly code by the 'call0' instruction. +*/ +// void XT_RTOS_INT_ENTER(void) +#define XT_RTOS_INT_ENTER _zxt_int_enter + +/* +Inform RTOS of completion of an interrupt handler, and give control to +RTOS to perform thread/task scheduling, switch back from any system stack +and restore the context, and return to the exit dispatcher saved in the +stack frame at XT_STK_EXIT. RTOS port can call0 _xt_context_restore +to save the context saved in XT_RTOS_INT_ENTER via _xt_context_save, +leaving only a minimal part of the context to be restored by the exit +dispatcher. This function does not return to the place it was called from. +May only be called from assembly code by the 'call0' instruction. +*/ +// void XT_RTOS_INT_EXIT(void) +#define XT_RTOS_INT_EXIT _zxt_int_exit + +/* +Inform RTOS of the occurrence of a tick timer interrupt. +If RTOS has no tick timer, leave XT_RTOS_TIMER_INT undefined. +May be coded in or called from C or assembly, per ABI conventions. +RTOS may optionally define XT_TICK_PER_SEC in its own way (eg. macro). +*/ +// void XT_RTOS_TIMER_INT(void) +#define XT_RTOS_TIMER_INT _zxt_timer_int +#define XT_TICK_PER_SEC CONFIG_SYS_CLOCK_TICKS_PER_SEC + +/* +Return in a15 the base address of the co-processor state save area for the +thread that triggered a co-processor exception, or 0 if no thread was running. +The state save area is structured as defined in xtensa_context.h and has size +XT_CP_SIZE. Co-processor instructions should only be used in thread code, never +in interrupt handlers or the RTOS kernel. May only be called from assembly code +and by the 'call0' instruction. A result of 0 indicates an unrecoverable error. +The implementation may use only a2-4, a15 (all other regs must be preserved). +*/ +// void* XT_RTOS_CP_STATE(void) +#define XT_RTOS_CP_STATE _zxt_task_coproc_state + + +/******************************************************************************* + +HOOKS TO DYNAMICALLY INSTALL INTERRUPT AND EXCEPTION HANDLERS PER LEVEL. + +This Xtensa RTOS port provides hooks for dynamically installing exception +and interrupt handlers to facilitate automated testing where each test +case can install its own handler for user exceptions and each interrupt +priority (level). This consists of an array of function pointers indexed +by interrupt priority, with index 0 being the user exception handler hook. +Each entry in the array is initially 0, and may be replaced by a function +pointer of type XT_INTEXC_HOOK. A handler may be uninstalled by installing 0. + +The handler for low and medium priority obeys ABI conventions so may be coded +in C. For the exception handler, the cause is the contents of the EXCCAUSE +reg, and the result is -1 if handled, else the cause (still needs handling). +For interrupt handlers, the cause is a mask of pending enabled interrupts at +that level, and the result is the same mask with the bits for the handled +interrupts cleared (those not cleared still need handling). This allows a test +case to either pre-handle or override the default handling for the exception +or interrupt level (see xtensa_vectors.S). + +High priority handlers (including NMI) must be coded in assembly, are always +called by 'call0' regardless of ABI, must preserve all registers except a0, +and must not use or modify the interrupted stack. The hook argument 'cause' +is not passed and the result is ignored, so as not to burden the caller with +saving and restoring a2 (it assumes only one interrupt per level - see the +discussion in high priority interrupts in xtensa_vectors.S). The handler +therefore should be coded to prototype 'void h(void)' even though it plugs +into an array of handlers of prototype 'unsigned h(unsigned)'. + +To enable interrupt/exception hooks, compile the RTOS with '-DXT_INTEXC_HOOKS'. + +*******************************************************************************/ + +#define XT_INTEXC_HOOK_NUM (1 + XCHAL_NUM_INTLEVELS + XCHAL_HAVE_NMI) + +#ifndef __ASSEMBLER__ +typedef unsigned (*XT_INTEXC_HOOK)(unsigned cause); +extern volatile XT_INTEXC_HOOK _xt_intexc_hooks[XT_INTEXC_HOOK_NUM]; +#endif + + +/******************************************************************************* + +CONVENIENCE INCLUSIONS. + +Ensures RTOS specific files need only include this one Xtensa-generic header. +These headers are included last so they can use the RTOS definitions above. + +*******************************************************************************/ + +#include "xtensa_context.h" + +#ifdef XT_RTOS_TIMER_INT +#include "xtensa_timer.h" +#endif + + +/******************************************************************************* + +Xtensa Port Version. + +*******************************************************************************/ + +#define XTENSA_PORT_VERSION 1.5.0 +#define XTENSA_PORT_VERSION_STRING "1.5.0" + +#endif /* XTENSA_RTOS_H */ |