begriffs open source - freertos/blob - portable/GCC/H8S2329/port.c

1 /*

2 * FreeRTOS SMP Kernel V202110.00

4 *

5 * Permission is hereby granted, free of charge, to any person obtaining a copy of

6 * this software and associated documentation files (the "Software"), to deal in

7 * the Software without restriction, including without limitation the rights to

8 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of

9 * the Software, and to permit persons to whom the Software is furnished to do so,

10 * subject to the following conditions:

11 *

12 * The above copyright notice and this permission notice shall be included in all

13 * copies or substantial portions of the Software.

14 *

15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS

17 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR

18 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER

19 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

20 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

21 *

22 * https://www.FreeRTOS.org

23 * https://github.com/FreeRTOS

24 *

25 * 1 tab == 4 spaces!

26 */

28 /* Scheduler includes. */

29 #include "FreeRTOS.h"

30 #include "task.h"

33 /*-----------------------------------------------------------

34 * Implementation of functions defined in portable.h for the H8S port.

35 *----------------------------------------------------------*/

38 /*-----------------------------------------------------------*/

40 /* When the task starts interrupts should be enabled. */

41 #define portINITIAL_CCR ( ( StackType_t ) 0x00 )

43 /* Hardware specific constants used to generate the RTOS tick from the TPU. */

44 #define portCLEAR_ON_TGRA_COMPARE_MATCH ( ( uint8_t ) 0x20 )

45 #define portCLOCK_DIV_64 ( ( uint8_t ) 0x03 )

46 #define portCLOCK_DIV ( ( uint32_t ) 64 )

47 #define portTGRA_INTERRUPT_ENABLE ( ( uint8_t ) 0x01 )

48 #define portTIMER_CHANNEL ( ( uint8_t ) 0x02 )

49 #define portMSTP13 ( ( uint16_t ) 0x2000 )

51 /*

52 * Setup TPU channel one for the RTOS tick at the requested frequency.

53 */

54 static void prvSetupTimerInterrupt( void );

56 /*

57 * The ISR used by portYIELD(). This is installed as a trap handler.

58 */

59 void vPortYield( void ) __attribute__ ( ( saveall, interrupt_handler ) );

61 /*-----------------------------------------------------------*/

63 /*

64 * See header file for description.

65 */

66 StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )

67 {

68 uint32_t ulValue;

70 /* This requires an even address. */

71 ulValue = ( uint32_t ) pxTopOfStack;

72 if( ulValue & 1UL )

73 {

74 pxTopOfStack = pxTopOfStack - 1;

75 }

77 /* Place a few bytes of known values on the bottom of the stack.

78 This is just useful for debugging. */

79 pxTopOfStack--;

80 *pxTopOfStack = 0xaa;

81 pxTopOfStack--;

82 *pxTopOfStack = 0xbb;

83 pxTopOfStack--;

84 *pxTopOfStack = 0xcc;

85 pxTopOfStack--;

86 *pxTopOfStack = 0xdd;

88 /* The initial stack mimics an interrupt stack. First there is the program

89 counter (24 bits). */

90 ulValue = ( uint32_t ) pxCode;

92 pxTopOfStack--;

93 *pxTopOfStack = ( StackType_t ) ( ulValue & 0xff );

94 pxTopOfStack--;

95 ulValue >>= 8UL;

96 *pxTopOfStack = ( StackType_t ) ( ulValue & 0xff );

97 pxTopOfStack--;

98 ulValue >>= 8UL;

99 *pxTopOfStack = ( StackType_t ) ( ulValue & 0xff );

100

101 /* Followed by the CCR. */

102 pxTopOfStack--;

103 *pxTopOfStack = portINITIAL_CCR;

104

105 /* Next all the general purpose registers - with the parameters being passed

106 in ER0. The parameter order must match that used by the compiler when the

107 "saveall" function attribute is used. */

108

109 /* ER6 */

110 pxTopOfStack--;

111 *pxTopOfStack = 0x66;

112 pxTopOfStack--;

113 *pxTopOfStack = 0x66;

114 pxTopOfStack--;

115 *pxTopOfStack = 0x66;

116 pxTopOfStack--;

117 *pxTopOfStack = 0x66;

118

119 /* ER0 */

120 ulValue = ( uint32_t ) pvParameters;

121

122 pxTopOfStack--;

123 *pxTopOfStack = ( StackType_t ) ( ulValue & 0xff );

124 pxTopOfStack--;

125 ulValue >>= 8UL;

126 *pxTopOfStack = ( StackType_t ) ( ulValue & 0xff );

127 pxTopOfStack--;

128 ulValue >>= 8UL;

129 *pxTopOfStack = ( StackType_t ) ( ulValue & 0xff );

130 pxTopOfStack--;

131 ulValue >>= 8UL;

132 *pxTopOfStack = ( StackType_t ) ( ulValue & 0xff );

133

134 /* ER1 */

135 pxTopOfStack--;

136 *pxTopOfStack = 0x11;

137 pxTopOfStack--;

138 *pxTopOfStack = 0x11;

139 pxTopOfStack--;

140 *pxTopOfStack = 0x11;

141 pxTopOfStack--;

142 *pxTopOfStack = 0x11;

143

144 /* ER2 */

145 pxTopOfStack--;

146 *pxTopOfStack = 0x22;

147 pxTopOfStack--;

148 *pxTopOfStack = 0x22;

149 pxTopOfStack--;

150 *pxTopOfStack = 0x22;

151 pxTopOfStack--;

152 *pxTopOfStack = 0x22;

153

154 /* ER3 */

155 pxTopOfStack--;

156 *pxTopOfStack = 0x33;

157 pxTopOfStack--;

158 *pxTopOfStack = 0x33;

159 pxTopOfStack--;

160 *pxTopOfStack = 0x33;

161 pxTopOfStack--;

162 *pxTopOfStack = 0x33;

163

164 /* ER4 */

165 pxTopOfStack--;

166 *pxTopOfStack = 0x44;

167 pxTopOfStack--;

168 *pxTopOfStack = 0x44;

169 pxTopOfStack--;

170 *pxTopOfStack = 0x44;

171 pxTopOfStack--;

172 *pxTopOfStack = 0x44;

173

174 /* ER5 */

175 pxTopOfStack--;

176 *pxTopOfStack = 0x55;

177 pxTopOfStack--;

178 *pxTopOfStack = 0x55;

179 pxTopOfStack--;

180 *pxTopOfStack = 0x55;

181 pxTopOfStack--;

182 *pxTopOfStack = 0x55;

183

184 return pxTopOfStack;

185 }

186 /*-----------------------------------------------------------*/

187

188 BaseType_t xPortStartScheduler( void )

189 {

190 extern void * pxCurrentTCB;

191

192 /* Setup the hardware to generate the tick. */

193 prvSetupTimerInterrupt();

194

195 /* Restore the context of the first task that is going to run. This

196 mirrors the function epilogue code generated by the compiler when the

197 "saveall" function attribute is used. */

198 asm volatile (

199 "MOV.L @_pxCurrentTCB, ER6 \n\t"

200 "MOV.L @ER6, ER7 \n\t"

201 "LDM.L @SP+, (ER4-ER5) \n\t"

202 "LDM.L @SP+, (ER0-ER3) \n\t"

203 "MOV.L @ER7+, ER6 \n\t"

204 "RTE \n\t"

205 );

206

207 ( void ) pxCurrentTCB;

208

209 /* Should not get here. */

210 return pdTRUE;

211 }

212 /*-----------------------------------------------------------*/

213

214 void vPortEndScheduler( void )

215 {

216 /* It is unlikely that the h8 port will get stopped. */

217 }

218 /*-----------------------------------------------------------*/

219

220 /*

221 * Manual context switch. This is a trap handler. The "saveall" function

222 * attribute is used so the context is saved by the compiler prologue. All

223 * we have to do is save the stack pointer.

224 */

225 void vPortYield( void )

226 {

227 portSAVE_STACK_POINTER();

228 vTaskSwitchContext();

229 portRESTORE_STACK_POINTER();

230 }

231 /*-----------------------------------------------------------*/

232

233 /*

234 * The interrupt handler installed for the RTOS tick depends on whether the

235 * preemptive or cooperative scheduler is being used.

236 */

237 #if( configUSE_PREEMPTION == 1 )

238

239 /*

240 * The preemptive scheduler is used so the ISR calls vTaskSwitchContext().

241 * The function prologue saves the context so all we have to do is save

242 * the stack pointer.

243 */

244 void vTickISR( void ) __attribute__ ( ( saveall, interrupt_handler ) );

245 void vTickISR( void )

246 {

247 portSAVE_STACK_POINTER();

248

249 if( xTaskIncrementTick() != pdFALSE )

250 {

251 vTaskSwitchContext();

252 }

253

254 /* Clear the interrupt. */

255 TSR1 &= ~0x01;

256

257 portRESTORE_STACK_POINTER();

258 }

259

260 #else

261

262 /*

263 * The cooperative scheduler is being used so all we have to do is

264 * periodically increment the tick. This can just be a normal ISR and

265 * the "saveall" attribute is not required.

266 */

267 void vTickISR( void ) __attribute__ ( ( interrupt_handler ) );

268 void vTickISR( void )

269 {

270 xTaskIncrementTick();

271

272 /* Clear the interrupt. */

273 TSR1 &= ~0x01;

274 }

275

276 #endif

277 /*-----------------------------------------------------------*/

278

279 /*

280 * Setup timer 1 compare match to generate a tick interrupt.

281 */

282 static void prvSetupTimerInterrupt( void )

283 {

284 const uint32_t ulCompareMatch = ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) / portCLOCK_DIV;

285

286 /* Turn the module on. */

287 MSTPCR &= ~portMSTP13;

288

289 /* Configure timer 1. */

290 TCR1 = portCLEAR_ON_TGRA_COMPARE_MATCH | portCLOCK_DIV_64;

291

292 /* Configure the compare match value for a tick of configTICK_RATE_HZ. */

293 TGR1A = ulCompareMatch;

294

295 /* Start the timer and enable the interrupt - we can do this here as

296 interrupts are globally disabled when this function is called. */

297 TIER1 |= portTGRA_INTERRUPT_ENABLE;

298 TSTR |= portTIMER_CHANNEL;

299 }

300 /*-----------------------------------------------------------*/

301

302

303