zephyr/arch/xtensa/include/xtensa_config.h

142 lines
4.8 KiB
C

/*
* Copyright (c) 2016 Cadence Design Systems, Inc.
* SPDX-License-Identifier: Apache-2.0
*/
#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 threads 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 threads 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 */