1 /*
2 * FreeRTOS Kernel V11.0.1
3 * Copyright (C) 2015-2019 Cadence Design Systems, Inc.
4 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
5 *
6 * SPDX-License-Identifier: MIT
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy of
9 * this software and associated documentation files (the "Software"), to deal in
10 * the Software without restriction, including without limitation the rights to
11 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
12 * the Software, and to permit persons to whom the Software is furnished to do so,
13 * subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in all
16 * copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
20 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
21 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
22 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
23 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24 *
25 * https://www.FreeRTOS.org
26 * https://github.com/FreeRTOS
27 *
28 */
29
30 #include <stdlib.h>
31 #include <xtensa/config/core.h>
32
33 #include "xtensa_rtos.h"
34
35 #include "FreeRTOS.h"
36 #include "task.h"
37
38
39 /* Defined in portasm.h */
40 extern void _frxt_tick_timer_init( void );
41
42 /* Defined in xtensa_context.S */
43 extern void _xt_coproc_init( void );
44
45
46 /*-----------------------------------------------------------*/
47
48 /* We require the address of the pxCurrentTCB variable, but don't want to know
49 * any details of its type. */
50 typedef void TCB_t;
51 extern volatile TCB_t * volatile pxCurrentTCB;
52
53 unsigned port_xSchedulerRunning = 0; /* Duplicate of inaccessible xSchedulerRunning; needed at startup to avoid counting nesting */
54 unsigned port_interruptNesting = 0; /* Interrupt nesting level */
55
56 /*-----------------------------------------------------------*/
57
58 /* User exception dispatcher when exiting */
59 void _xt_user_exit( void );
60
61 /*
62 * Stack initialization
63 */
64 #if portUSING_MPU_WRAPPERS
pxPortInitialiseStack(StackType_t * pxTopOfStack,TaskFunction_t pxCode,void * pvParameters,BaseType_t xRunPrivileged)65 StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
66 TaskFunction_t pxCode,
67 void * pvParameters,
68 BaseType_t xRunPrivileged )
69 #else
70 StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
71 TaskFunction_t pxCode,
72 void * pvParameters )
73 #endif
74 {
75 StackType_t * sp;
76 StackType_t * tp;
77 XtExcFrame * frame;
78
79 #if XCHAL_CP_NUM > 0
80 uint32_t * p;
81 #endif
82
83 /* Create interrupt stack frame aligned to 16 byte boundary */
84 sp = ( StackType_t * ) ( ( ( UBaseType_t ) pxTopOfStack - XT_CP_SIZE - XT_STK_FRMSZ ) & ~0xf );
85
86 /* Clear the entire frame (do not use memset() because we don't depend on C library) */
87 for( tp = sp; tp <= pxTopOfStack; ++tp )
88 {
89 *tp = 0;
90 }
91
92 frame = ( XtExcFrame * ) sp;
93
94 /* Explicitly initialize certain saved registers */
95 frame->pc = ( UBaseType_t ) pxCode; /* task entrypoint */
96 frame->a0 = 0; /* to terminate GDB backtrace */
97 frame->a1 = ( UBaseType_t ) sp + XT_STK_FRMSZ; /* physical top of stack frame */
98 frame->exit = ( UBaseType_t ) _xt_user_exit; /* user exception exit dispatcher */
99
100 /* Set initial PS to int level 0, EXCM disabled ('rfe' will enable), user mode. */
101 /* Also set entry point argument parameter. */
102 #ifdef __XTENSA_CALL0_ABI__
103 frame->a2 = ( UBaseType_t ) pvParameters;
104 frame->ps = PS_UM | PS_EXCM;
105 #else
106 /* + for windowed ABI also set WOE and CALLINC (pretend task was 'call4'd). */
107 frame->a6 = ( UBaseType_t ) pvParameters;
108 frame->ps = PS_UM | PS_EXCM | PS_WOE | PS_CALLINC( 1 );
109 #endif
110
111 #ifdef XT_USE_SWPRI
112 /* Set the initial virtual priority mask value to all 1's. */
113 frame->vpri = 0xFFFFFFFF;
114 #endif
115
116 #if XCHAL_CP_NUM > 0
117 /* Init the coprocessor save area (see xtensa_context.h) */
118
119 /* No access to TCB here, so derive indirectly. Stack growth is top to bottom.
120 * //p = (uint32_t *) xMPUSettings->coproc_area;
121 */
122 p = ( uint32_t * ) ( ( ( uint32_t ) pxTopOfStack - XT_CP_SIZE ) & ~0xf );
123 configASSERT( ( uint32_t ) p >= frame->a1 );
124 p[ 0 ] = 0;
125 p[ 1 ] = 0;
126 p[ 2 ] = ( ( ( uint32_t ) p ) + 12 + XCHAL_TOTAL_SA_ALIGN - 1 ) & -XCHAL_TOTAL_SA_ALIGN;
127 #endif
128
129 return sp;
130 }
131
132 /*-----------------------------------------------------------*/
133
vPortEndScheduler(void)134 void vPortEndScheduler( void )
135 {
136 /* It is unlikely that the Xtensa port will get stopped. If required simply
137 * disable the tick interrupt here. */
138 }
139
140 /*-----------------------------------------------------------*/
141
xPortStartScheduler(void)142 BaseType_t xPortStartScheduler( void )
143 {
144 /* Interrupts are disabled at this point and stack contains PS with enabled interrupts when task context is restored */
145
146 #if XCHAL_CP_NUM > 0
147 /* Initialize co-processor management for tasks. Leave CPENABLE alone. */
148 _xt_coproc_init();
149 #endif
150
151 /* Init the tick divisor value */
152 _xt_tick_divisor_init();
153
154 /* Setup the hardware to generate the tick. */
155 _frxt_tick_timer_init();
156
157 #if XT_USE_THREAD_SAFE_CLIB
158 /* Init C library */
159 vPortClibInit();
160 #endif
161
162 port_xSchedulerRunning = 1;
163
164 /* Cannot be directly called from C; never returns */
165 __asm__ volatile ( "call0 _frxt_dispatch\n" );
166
167 /* Should not get here. */
168 return pdTRUE;
169 }
170 /*-----------------------------------------------------------*/
171
xPortSysTickHandler(void)172 BaseType_t xPortSysTickHandler( void )
173 {
174 BaseType_t ret;
175 uint32_t interruptMask;
176
177 portbenchmarkIntLatency();
178
179 /* Interrupts upto configMAX_SYSCALL_INTERRUPT_PRIORITY must be
180 * disabled before calling xTaskIncrementTick as it access the
181 * kernel lists. */
182 interruptMask = portSET_INTERRUPT_MASK_FROM_ISR();
183 {
184 ret = xTaskIncrementTick();
185 }
186 portCLEAR_INTERRUPT_MASK_FROM_ISR( interruptMask );
187
188 portYIELD_FROM_ISR( ret );
189
190 return ret;
191 }
192 /*-----------------------------------------------------------*/
193
194 /*
195 * Used to set coprocessor area in stack. Current hack is to reuse MPU pointer for coprocessor area.
196 */
197 #if portUSING_MPU_WRAPPERS
vPortStoreTaskMPUSettings(xMPU_SETTINGS * xMPUSettings,const struct xMEMORY_REGION * const xRegions,StackType_t * pxBottomOfStack,uint32_t ulStackDepth)198 void vPortStoreTaskMPUSettings( xMPU_SETTINGS * xMPUSettings,
199 const struct xMEMORY_REGION * const xRegions,
200 StackType_t * pxBottomOfStack,
201 uint32_t ulStackDepth )
202 {
203 #if XCHAL_CP_NUM > 0
204 xMPUSettings->coproc_area = ( StackType_t * ) ( ( uint32_t ) ( pxBottomOfStack + ulStackDepth - 1 ) );
205 xMPUSettings->coproc_area = ( StackType_t * ) ( ( ( portPOINTER_SIZE_TYPE ) xMPUSettings->coproc_area ) & ( ~( ( portPOINTER_SIZE_TYPE ) portBYTE_ALIGNMENT_MASK ) ) );
206 xMPUSettings->coproc_area = ( StackType_t * ) ( ( ( uint32_t ) xMPUSettings->coproc_area - XT_CP_SIZE ) & ~0xf );
207
208 /* NOTE: we cannot initialize the coprocessor save area here because FreeRTOS is going to
209 * clear the stack area after we return. This is done in pxPortInitialiseStack().
210 */
211 #endif
212 }
213 #endif /* if portUSING_MPU_WRAPPERS */
214
