zephyr/arch/xtensa/include/xtensa_config.h

148 lines
6.0 KiB
C

/*
* Copyright (c) 2016 Cadence Design Systems, Inc.
* SPDX-License-Identifier: Apache-2.0
*/
/*******************************************************************************
Configuration-specific information for Xtensa build. This file must be
included in FreeRTOSConfig.h to properly set up the config-dependent
parameters correctly.
NOTE: To enable thread-safe C library support, XT_USE_THREAD_SAFE_CLIB must
be defined to be > 0 somewhere above or on the command line.
*******************************************************************************/
#ifndef XTENSA_CONFIG_H
#define XTENSA_CONFIG_H
#ifdef __cplusplus
extern "C" {
#endif
#include <xtensa/hal.h>
#include <xtensa/config/core.h>
#include <xtensa/config/system.h> /* required for XSHAL_CLIB */
#include "xtensa_context.h"
/*-----------------------------------------------------------------------------
* STACK REQUIREMENTS
*
* This section defines the minimum stack size, and the extra space required to
* be allocated for saving coprocessor state and/or C library state information
* (if thread safety is enabled for the C library). The sizes are in bytes.
*
* Stack sizes for individual tasks should be derived from these minima based on
* the maximum call depth of the task and the maximum level of interrupt nesting.
* A minimum stack size is defined by XT_STACK_MIN_SIZE. This minimum is based
* on the requirement for a task that calls nothing else but can be interrupted.
* This assumes that interrupt handlers do not call more than a few levels deep.
* If this is not true, i.e. one or more interrupt handlers make deep calls then
* the minimum must be increased.
*
* If the Xtensa processor configuration includes coprocessors, then space is
* allocated to save the coprocessor state on the stack.
*
* If thread safety is enabled for the C runtime library, (XT_USE_THREAD_SAFE_CLIB
* is defined) then space is allocated to save the C library context in the TCB.
*
* Allocating insufficient stack space is a common source of hard-to-find errors.
* During development, it is best to enable the FreeRTOS stack checking features.
*
* Usage:
*
* XT_USE_THREAD_SAFE_CLIB -- Define this to a nonzero value to enable thread-safe
* use of the C library. This will require extra stack
* space to be allocated for tasks that use the C library
* reentrant functions. See below for more information.
*
* NOTE: The Xtensa toolchain supports multiple C libraries and not all of them
* support thread safety. Check your core configuration to see which C library
* was chosen for your system.
*
* XT_STACK_MIN_SIZE -- The minimum stack size for any task. It is recommended
* that you do not use a stack smaller than this for any
* task. In case you want to use stacks smaller than this
* size, you must verify that the smaller size(s) will work
* under all operating conditions.
*
* XT_STACK_EXTRA -- The amount of extra stack space to allocate for a task
* that does not make C library reentrant calls. Add this
* to the amount of stack space required by the task itself.
*
* XT_STACK_EXTRA_CLIB -- The amount of space to allocate for C library state.
*
-----------------------------------------------------------------------------*/
/* Extra space required for interrupt/exception hooks. */
#ifdef XT_INTEXC_HOOKS
#ifdef __XTENSA_CALL0_ABI__
#define STK_INTEXC_EXTRA 0x200
#else
#define STK_INTEXC_EXTRA 0x180
#endif
#else
#define STK_INTEXC_EXTRA 0
#endif
/* Check C library thread safety support and compute size of C library save area. */
#if XT_USE_THREAD_SAFE_CLIB > 0u
#if XSHAL_CLIB == XTHAL_CLIB_XCLIB
#define XT_HAVE_THREAD_SAFE_CLIB 0
#error Thread-safe operation is not yet supported for the XCLIB C library.
#elif XSHAL_CLIB == XTHAL_CLIB_NEWLIB
#define XT_HAVE_THREAD_SAFE_CLIB 1
#if !defined __ASSEMBLER__
#include <sys/reent.h>
#define XT_CLIB_CONTEXT_AREA_SIZE ((sizeof(struct _reent) + 15) + (-16))
#define XT_CLIB_GLOBAL_PTR _impure_ptr
#endif
#else
#define XT_HAVE_THREAD_SAFE_CLIB 0
#error The selected C runtime library is not thread safe.
#endif
#else
#define XT_CLIB_CONTEXT_AREA_SIZE 0
#endif
/*------------------------------------------------------------------------------
Extra size -- interrupt frame plus coprocessor save area plus hook space.
NOTE: Make sure XT_INTEXC_HOOKS is undefined unless you really need the hooks.
------------------------------------------------------------------------------*/
#ifdef __XTENSA_CALL0_ABI__
#define XT_XTRA_SIZE (XT_STK_FRMSZ + STK_INTEXC_EXTRA + 0x10 + XT_CP_SIZE)
#else
#define XT_XTRA_SIZE (XT_STK_FRMSZ + STK_INTEXC_EXTRA + 0x20 + XT_CP_SIZE)
#endif
/*------------------------------------------------------------------------------
Space allocated for user code -- function calls and local variables.
NOTE: This number can be adjusted to suit your needs. You must verify that the
amount of space you reserve is adequate for the worst-case conditions in your
application.
NOTE: The windowed ABI requires more stack, since space has to be reserved
for spilling register windows.
------------------------------------------------------------------------------*/
#ifdef __XTENSA_CALL0_ABI__
#define XT_USER_SIZE 0x200
#else
#define XT_USER_SIZE 0x400
#endif
/* Minimum recommended stack size. */
#define XT_STACK_MIN_SIZE ((XT_XTRA_SIZE + XT_USER_SIZE) / sizeof(unsigned char))
/* OS overhead with and without C library thread context. */
#define XT_STACK_EXTRA (XT_XTRA_SIZE)
#define XT_STACK_EXTRA_CLIB (XT_XTRA_SIZE + XT_CLIB_CONTEXT_AREA_SIZE)
#ifdef __cplusplus
}
#endif
#endif /* XTENSA_CONFIG_H */