stm32f4 __wfi

Jython googcheng at gmail.com
Wed Apr 24 08:25:06 UTC 2019


arm-rtems4.11-objdump -dS hello.exe | grep idle --color=auto -n -B 5 -A 12

there is no idle function which calls wfi command
// log
508-
509-
510-
511-    }
512-
513:    if((*USART2_SR) & (1<<4))  // idle
514-     3aa:    4b13          ldr    r3, [pc, #76]    ; (3f8
<USART2_handler+0x94>)
515-     3ac:    681b          ldr    r3, [r3, #0]
516-     3ae:    681b          ldr    r3, [r3, #0]
517-     3b0:    f003 0310     and.w    r3, r3, #16
518-     3b4:    2b00          cmp    r3, #0
519-     3b6:    d00a          beq.n    3ce <USART2_handler+0x6a>
520-    {
521:        //printk("idle ");
522-
523-        temp = (*USART2_SR);
524-     3b8:    4b0f          ldr    r3, [pc, #60]    ; (3f8
<USART2_handler+0x94>)
525-     3ba:    681b          ldr    r3, [r3, #0]
526-     3bc:    681b          ldr    r3, [r3, #0]
527-     3be:    60fb          str    r3, [r7, #12]
528-        temp = (*USART2_DR);
529-     3c0:    4b0f          ldr    r3, [pc, #60]    ; (400
<USART2_handler+0x9c>)
530-     3c2:    681b          ldr    r3, [r3, #0]
531-     3c4:    681b          ldr    r3, [r3, #0]
532-     3c6:    60fb          str    r3, [r7, #12]
533-        //temp = temp;
--
627-
628-
629-
630-    }
631-
632:    if((*USART3_SR) & (1<<4))  // idle
633-     44c:    4b12          ldr    r3, [pc, #72]    ; (498
<USART3_handler+0x8c>)
634-     44e:    681b          ldr    r3, [r3, #0]
635-     450:    681b          ldr    r3, [r3, #0]
636-     452:    f003 0310     and.w    r3, r3, #16
637-     456:    2b00          cmp    r3, #0
638-     458:    d00a          beq.n    470 <USART3_handler+0x64>
639-    {
640:        //printk("idle ");
641-
642-        temp = (*USART3_SR);
643-     45a:    4b0f          ldr    r3, [pc, #60]    ; (498
<USART3_handler+0x8c>)
644-     45c:    681b          ldr    r3, [r3, #0]
645-     45e:    681b          ldr    r3, [r3, #0]
646-     460:    60fb          str    r3, [r7, #12]
647-        temp = (*USART3_DR);
648-     462:    4b0f          ldr    r3, [pc, #60]    ; (4a0
<USART3_handler+0x94>)
649-     464:    681b          ldr    r3, [r3, #0]
650-     466:    681b          ldr    r3, [r3, #0]
651-     468:    60fb          str    r3, [r7, #12]
652-
--
26329-
26330-    if (newTail == tty->rawOutBuf.Head) {
26331-      /*
26332-       * Buffer has become empty
26333-       */
26334:      tty->rawOutBufState = rob_idle;
26335-    69a0:    f880 5094     strb.w    r5, [r0, #148]    ; 0x94
26336-      (*tty->handler.write) (ctx, NULL, 0);
26337-    69a4:    f8d4 30c4     ldr.w    r3, [r4, #196]    ; 0xc4
26338-    69a8:    4670          mov    r0, lr
26339-    69aa:    4629          mov    r1, r5
26340-    69ac:    462a          mov    r2, r5
26341-    69ae:    4798          blx    r3
26342-      nToSend = 0;
26343-
26344-      /*
26345-       * check to see if snd wakeup callback was set
26346-       */
--
26443-    6a12:    2600          movs    r6, #0
26444-    6a14:    e7ac          b.n    6970
<rtems_termios_refill_transmitter+0x7c>
26445-      /*
26446-       * Buffer has become empty
26447-       */
26448:      tty->rawOutBufState = rob_idle;
26449-      (*tty->handler.write) (ctx, NULL, 0);
26450-      nToSend = 0;
26451-    6a16:    461d          mov    r5, r3
26452-    6a18:    e7aa          b.n    6970
<rtems_termios_refill_transmitter+0x7c>
26453-    6a1a:    bf00          nop
26454-
26455-00006a1c <rtems_termios_txdaemon>:
26456-
26457-/*
26458- * this task actually processes any transmit events
26459- */
26460-static rtems_task rtems_termios_txdaemon(rtems_task_argument argument)
--
27083-      RTEMS_NO_PRIORITY,
27084-      &tty->rawOutBuf.Semaphore);
27085-    if (sc != RTEMS_SUCCESSFUL)
27086-    6cc0:    2800          cmp    r0, #0
27087-    6cc2:    f040 80d6     bne.w    6e72
<rtems_termios_open_tty+0x2de>
27088:    tty->rawOutBufState = rob_idle;
27089-
27090-    /*
27091-     * Set callbacks
27092-     */
27093-    if (device_node != NULL) {
27094-    6cc6:    9b0e          ldr    r3, [sp, #56]    ; 0x38
27095-      RTEMS_SIMPLE_BINARY_SEMAPHORE | RTEMS_FIFO,
27096-      RTEMS_NO_PRIORITY,
27097-      &tty->rawOutBuf.Semaphore);
27098-    if (sc != RTEMS_SUCCESSFUL)
27099-      rtems_fatal_error_occurred (sc);
27100:    tty->rawOutBufState = rob_idle;
27101-    6cc8:    f884 0094     strb.w    r0, [r4, #148]    ; 0x94
27102-
27103-    /*
27104-     * Set callbacks
27105-     */
27106-    if (device_node != NULL) {
27107-    6ccc:    2b00          cmp    r3, #0
27108-    6cce:    f000 80e9     beq.w    6ea4
<rtems_termios_open_tty+0x310>
27109-      device_node->tty = tty;
27110-      tty->handler = *device_node->handler;
27111-    6cd2:    f104 0cb8     add.w    ip, r4, #184    ; 0xb8
27112-    6cd6:    4666          mov    r6, ip
--
29226-      /* disable interrupts    */
29227-      rtems_termios_device_lock_acquire (ctx, &lock_context);
29228-      tty->flow_ctrl &= ~FL_OSTOP;
29229-    7442:    f8d4 30d8     ldr.w    r3, [r4, #216]    ; 0xd8
29230-      /* check for chars in output buffer (or rob_state?) */
29231:      if (tty->rawOutBufState != rob_idle) {
29232-    7446:    f894 2094     ldrb.w    r2, [r4, #148]    ; 0x94
29233-
29234-    /* has output been stopped due to received XOFF? */
29235-    if (tty->flow_ctrl & FL_OSTOP) {
29236-      /* disable interrupts    */
29237-      rtems_termios_device_lock_acquire (ctx, &lock_context);
29238-      tty->flow_ctrl &= ~FL_OSTOP;
29239-    744a:    f023 0320     bic.w    r3, r3, #32
29240-    744e:    f8c4 30d8     str.w    r3, [r4, #216]    ; 0xd8
29241-      /* check for chars in output buffer (or rob_state?) */
29242:      if (tty->rawOutBufState != rob_idle) {
29243-    7452:    2a00          cmp    r2, #0
29244-    7454:    f040 80cf     bne.w    75f6 <rtems_termios_ioctl+0x306>
29245-    ARM_SWITCH_BACK
29246-    : ARM_SWITCH_OUTPUT
29247-    : [level] "r" (level)
29248-  );
29249-#elif defined(ARM_MULTILIB_ARCH_V7M)
29250-  __asm__ volatile (
29251-    7458:    f387 8811     msr    BASEPRI, r7
29252-      /* reenable interrupts */
29253-      rtems_termios_device_lock_release (ctx, &lock_context);
29254-    }
--
29492-
29493-  rtems_termios_device_lock_acquire (ctx, &lock_context);
29494-  tty->rawOutBuf.Tail = 0;
29495-    7572:    f8c4 0084     str.w    r0, [r4, #132]    ; 0x84
29496-  tty->rawOutBuf.Head = 0;
29497:  tty->rawOutBufState = rob_idle;
29498-    7576:    f884 0094     strb.w    r0, [r4, #148]    ; 0x94
29499-  rtems_termios_device_context *ctx = tty->device_context;
29500-  rtems_interrupt_lock_context lock_context;
29501-
29502-  rtems_termios_device_lock_acquire (ctx, &lock_context);
29503-  tty->rawOutBuf.Tail = 0;
29504-  tty->rawOutBuf.Head = 0;
29505-    757a:    f8c4 0080     str.w    r0, [r4, #128]    ; 0x80
29506-    ARM_SWITCH_BACK
29507-    : ARM_SWITCH_OUTPUT
29508-    : [level] "r" (level)
29509-  );
--
29562-
29563-  rtems_termios_device_lock_acquire (ctx, &lock_context);
29564-  tty->rawOutBuf.Tail = 0;
29565-    75b0:    f8c4 0084     str.w    r0, [r4, #132]    ; 0x84
29566-  tty->rawOutBuf.Head = 0;
29567:  tty->rawOutBufState = rob_idle;
29568-    75b4:    f884 0094     strb.w    r0, [r4, #148]    ; 0x94
29569-  rtems_termios_device_context *ctx = tty->device_context;
29570-  rtems_interrupt_lock_context lock_context;
29571-
29572-  rtems_termios_device_lock_acquire (ctx, &lock_context);
29573-  tty->rawOutBuf.Tail = 0;
29574-  tty->rawOutBuf.Head = 0;
29575-    75b8:    f8c4 0080     str.w    r0, [r4, #128]    ; 0x80
29576-    ARM_SWITCH_BACK
29577-    : ARM_SWITCH_OUTPUT
29578-    : [level] "r" (level)
29579-  );
--
29629-    75f0:    2301          movs    r3, #1
29630-    75f2:    66e3          str    r3, [r4, #108]    ; 0x6c
29631-    75f4:    e77e          b.n    74f4 <rtems_termios_ioctl+0x204>
29632-      tty->flow_ctrl &= ~FL_OSTOP;
29633-      /* check for chars in output buffer (or rob_state?) */
29634:      if (tty->rawOutBufState != rob_idle) {
29635-        /* if chars available, call write function... */
29636-        (*tty->handler.write)(
29637-          ctx, &tty->rawOutBuf.theBuf[tty->rawOutBuf.Tail],1);
29638-    75f6:    f8d4 2084     ldr.w    r2, [r4, #132]    ; 0x84
29639-      rtems_termios_device_lock_acquire (ctx, &lock_context);
29640-      tty->flow_ctrl &= ~FL_OSTOP;
29641-      /* check for chars in output buffer (or rob_state?) */
29642:      if (tty->rawOutBufState != rob_idle) {
29643-        /* if chars available, call write function... */
29644-        (*tty->handler.write)(
29645-    75fa:    6fe1          ldr    r1, [r4, #124]    ; 0x7c
29646-    75fc:    f8d4 30c4     ldr.w    r3, [r4, #196]    ; 0xc4
29647-    7600:    4411          add    r1, r2
29648-    7602:    4628          mov    r0, r5
29649-    7604:    2201          movs    r2, #1
29650-    7606:    4798          blx    r3
29651-    7608:    e726          b.n    7458 <rtems_termios_ioctl+0x168>
29652-    760a:    bf00          nop
29653-
29654-0000760c <rtems_termios_puts>:
--
29815-    76b2:    bf24          itt    cs
29816-    76b4:    f8d4 2088     ldrcs.w    r2, [r4, #136]    ; 0x88
29817-    76b8:    1a9b          subcs    r3, r3, r2
29818-    tty->rawOutBuf.Head = newHead;
29819-
29820:    if (tty->rawOutBufState == rob_idle) {
29821-    76ba:    f894 2094     ldrb.w    r2, [r4, #148]    ; 0x94
29822-    memcpy(&tty->rawOutBuf.theBuf[tty->rawOutBuf.Head], buf, nToCopy);
29823-
29824-    newHead = tty->rawOutBuf.Head + nToCopy;
29825-    if (newHead >= tty->rawOutBuf.Size)
29826-      newHead -= tty->rawOutBuf.Size;
29827-    tty->rawOutBuf.Head = newHead;
29828-    76be:    f8c4 3080     str.w    r3, [r4, #128]    ; 0x80
29829-
29830:    if (tty->rawOutBufState == rob_idle) {
29831-    76c2:    b192          cbz    r2, 76ea <rtems_termios_puts+0xde>
29832-    ARM_SWITCH_BACK
29833-    : ARM_SWITCH_OUTPUT
29834-    : [level] "r" (level)
29835-  );
29836-#elif defined(ARM_MULTILIB_ARCH_V7M)
29837-  __asm__ volatile (
29838-    76c4:    f385 8811     msr    BASEPRI, r5
29839-  if (tty->handler.mode == TERMIOS_POLLED) {
29840-    (*tty->handler.write)(ctx, buf, len);
29841-    return;
29842-  }
--
29885-    76e8:    e7d2          b.n    7690 <rtems_termios_puts+0x84>
29886-    if (newHead >= tty->rawOutBuf.Size)
29887-      newHead -= tty->rawOutBuf.Size;
29888-    tty->rawOutBuf.Head = newHead;
29889-
29890:    if (tty->rawOutBufState == rob_idle) {
29891-      startXmit (tty, tty->rawOutBuf.Tail, false);
29892-    76ea:    f8d4 1084     ldr.w    r1, [r4, #132]    ; 0x84
29893-    76ee:    4620          mov    r0, r4
29894-    76f0:    f7ff f8ca     bl    6888 <startXmit>
29895-    76f4:    e7e6          b.n    76c4 <rtems_termios_puts+0xb8>
29896-  rtems_termios_device_context *ctx = tty->device_context;
29897-  rtems_interrupt_lock_context lock_context;
29898-  rtems_status_code sc;
29899-
29900-  if (tty->handler.mode == TERMIOS_POLLED) {
29901-    (*tty->handler.write)(ctx, buf, len);
29902-    76f6:    f8d2 30c4     ldr.w    r3, [r2, #196]    ; 0xc4
--
31283-    while ((tty->rawInBuf.Head != tty->rawInBuf.Tail) &&
31284-    7be4:    428a          cmp    r2, r1
31285-    7be6:    f04f 0501     mov.w    r5, #1
31286-    7bea:    d968          bls.n    7cbe <rtems_termios_read+0x1a6>
31287-             ==                (FL_MDXON | FL_ISNTXOF))
31288:            && ((tty->rawOutBufState == rob_idle)
31289-          || (tty->flow_ctrl & FL_OSTOP))) {
31290-          /* XON should be sent now... */
31291-          (*tty->handler.write)(
31292-            tty->device_context, (void
*)&(tty->termios.c_cc[VSTART]), 1);
31293-    7bec:    f104 0849     add.w    r8, r4, #73    ; 0x49
31294-    7bf0:    e012          b.n    7c18 <rtems_termios_read+0x100>
31295-
31296-      rtems_termios_device_lock_release (ctx, &lock_context);
31297-
31298-      /* continue processing new character */
31299-      if (tty->termios.c_lflag & ICANON) {
31300-        if (siproc (c, tty))
--
31401-        if (((tty->flow_ctrl & (FL_MDXON | FL_ISNTXOF))
31402-    7c56:    f8d4 20d8     ldr.w    r2, [r4, #216]    ; 0xd8
31403-    7c5a:    4013          ands    r3, r2
31404-    7c5c:    4553          cmp    r3, sl
31405-    7c5e:    d01e          beq.n    7c9e <rtems_termios_read+0x186>
31406:            && ((tty->rawOutBufState == rob_idle)
31407-          || (tty->flow_ctrl & FL_OSTOP))) {
31408-          /* XON should be sent now... */
31409-          (*tty->handler.write)(
31410-            tty->device_context, (void
*)&(tty->termios.c_cc[VSTART]), 1);
31411-        } else if (tty->flow_ctrl & FL_MDRTS) {
31412-    7c60:    f8d4 30d8     ldr.w    r3, [r4, #216]    ; 0xd8
31413-    7c64:    05da          lsls    r2, r3, #23
31414-    7c66:    d50b          bpl.n    7c80 <rtems_termios_read+0x168>
31415-          tty->flow_ctrl &= ~FL_IRTSOFF;
31416-    7c68:    f8d4 30d8     ldr.w    r3, [r4, #216]    ; 0xd8
31417-          /* activate RTS line */
31418-          if (tty->flow.start_remote_tx != NULL) {
--
31477-         < tty->lowwater) {
31478-        tty->flow_ctrl &= ~FL_IREQXOF;
31479-        /* if tx stopped and XON should be sent... */
31480-        if (((tty->flow_ctrl & (FL_MDXON | FL_ISNTXOF))
31481-             ==                (FL_MDXON | FL_ISNTXOF))
31482:            && ((tty->rawOutBufState == rob_idle)
31483-    7c9e:    f894 3094     ldrb.w    r3, [r4, #148]    ; 0x94
31484-    7ca2:    b11b          cbz    r3, 7cac <rtems_termios_read+0x194>
31485-          || (tty->flow_ctrl & FL_OSTOP))) {
31486-    7ca4:    f8d4 30d8     ldr.w    r3, [r4, #216]    ; 0xd8
31487-    7ca8:    0699          lsls    r1, r3, #26
31488-    7caa:    d5d9          bpl.n    7c60 <rtems_termios_read+0x148>
31489-          /* XON should be sent now... */
31490-          (*tty->handler.write)(
31491-    7cac:    f8d4 30c4     ldr.w    r3, [r4, #196]    ; 0xc4
31492-    7cb0:    f8d4 010c     ldr.w    r0, [r4, #268]    ; 0x10c
31493-    7cb4:    4641          mov    r1, r8
31494-    7cb6:    2201          movs    r2, #1
--
32101-        /* disable interrupts    */
32102-        rtems_termios_device_lock_acquire (ctx, &lock_context);
32103-        tty->flow_ctrl &= ~FL_OSTOP;
32104-    7f34:    f8d4 30d8     ldr.w    r3, [r4, #216]    ; 0xd8
32105-        /* check for chars in output buffer (or rob_state?) */
32106:        if (tty->rawOutBufState != rob_idle) {
32107-    7f38:    f894 2094     ldrb.w    r2, [r4, #148]    ; 0x94
32108-    if (flow_rcv) {
32109-      /* restart output according to FL_ORCVXOF flag */
32110-      if ((tty->flow_ctrl & (FL_ORCVXOF | FL_OSTOP)) == FL_OSTOP) {
32111-        /* disable interrupts    */
32112-        rtems_termios_device_lock_acquire (ctx, &lock_context);
32113-        tty->flow_ctrl &= ~FL_OSTOP;
32114-    7f3c:    f023 0320     bic.w    r3, r3, #32
32115-    7f40:    f8c4 30d8     str.w    r3, [r4, #216]    ; 0xd8
32116-        /* check for chars in output buffer (or rob_state?) */
32117:        if (tty->rawOutBufState != rob_idle) {
32118-    7f44:    b94a          cbnz    r2, 7f5a
<rtems_termios_enqueue_raw_characters+0x1ca>
32119-    ARM_SWITCH_BACK
32120-    : ARM_SWITCH_OUTPUT
32121-    : [level] "r" (level)
32122-  );
32123-#elif defined(ARM_MULTILIB_ARCH_V7M)
32124-  __asm__ volatile (
32125-    7f46:    f386 8811     msr    BASEPRI, r6
32126-    7f4a:    2601          movs    r6, #1
32127-    7f4c:    e760          b.n    7e10
<rtems_termios_enqueue_raw_characters+0x80>
32128-        if (( !tty->tty_rcvwakeup ) && ( tty->tty_rcv.sw_pfn != NULL
)) {
32129-          (*tty->tty_rcv.sw_pfn)(&tty->termios, tty->tty_rcv.sw_arg);
--
32136-    7f52:    9300          str    r3, [sp, #0]
32137-    7f54:    f38a 8811     msr    BASEPRI, sl
32138-    7f58:    e75a          b.n    7e10
<rtems_termios_enqueue_raw_characters+0x80>
32139-        tty->flow_ctrl &= ~FL_OSTOP;
32140-        /* check for chars in output buffer (or rob_state?) */
32141:        if (tty->rawOutBufState != rob_idle) {
32142-          /* if chars available, call write function... */
32143-          (*tty->handler.write)(
32144-            ctx, &tty->rawOutBuf.theBuf[tty->rawOutBuf.Tail], 1);
32145-    7f5a:    f8d4 2084     ldr.w    r2, [r4, #132]    ; 0x84
32146-        rtems_termios_device_lock_acquire (ctx, &lock_context);
32147-        tty->flow_ctrl &= ~FL_OSTOP;
32148-        /* check for chars in output buffer (or rob_state?) */
32149:        if (tty->rawOutBufState != rob_idle) {
32150-          /* if chars available, call write function... */
32151-          (*tty->handler.write)(
32152-    7f5e:    6fe1          ldr    r1, [r4, #124]    ; 0x7c
32153-    7f60:    f8d4 30c4     ldr.w    r3, [r4, #196]    ; 0xc4
32154-    7f64:    4411          add    r1, r2
32155-    7f66:    4658          mov    r0, fp
32156-    7f68:    2201          movs    r2, #1
32157-    7f6a:    f8cd c004     str.w    ip, [sp, #4]
32158-    7f6e:    4798          blx    r3
32159-    7f70:    f8dd c004     ldr.w    ip, [sp, #4]
32160-    7f74:    e7e7          b.n    7f46
<rtems_termios_enqueue_raw_characters+0x1b6>
32161-          + tty->rawInBuf.Size) % tty->rawInBuf.Size) >
tty->highwater)) {
--
32167-    7f76:    0692          lsls    r2, r2, #26
32168-    7f78:    d403          bmi.n    7f82
<rtems_termios_enqueue_raw_characters+0x1f2>
32169-    7f7a:    f894 2094     ldrb.w    r2, [r4, #148]    ; 0x94
32170-    7f7e:    2a00          cmp    r2, #0
32171-    7f80:    d18c          bne.n    7e9c
<rtems_termios_enqueue_raw_characters+0x10c>
32172:              (tty->rawOutBufState == rob_idle)) {
32173-            /* if tx is stopped due to XOFF or out of data */
32174-            /*    call write function here                 */
32175-            tty->flow_ctrl |= FL_ISNTXOF;
32176-    7f82:    f8d4 20d8     ldr.w    r2, [r4, #216]    ; 0xd8
32177-    7f86:    9301          str    r3, [sp, #4]
32178-    7f88:    f042 0202     orr.w    r2, r2, #2
32179-    7f8c:    f8c4 20d8     str.w    r2, [r4, #216]    ; 0xd8
32180-            (*tty->handler.write)(ctx,
32181-    7f90:    f8d4 30c4     ldr.w    r3, [r4, #196]    ; 0xc4
32182-    7f94:    4658          mov    r0, fp
32183-    7f96:    f104 014a     add.w    r1, r4, #74    ; 0x4a
32184-    7f9a:    2201          movs    r2, #1
--
38521-    9512:    f000 f825     bl    9560
<_Extension_Manager_initialization>
38522-
38523-  _POSIX_API_Initialize();
38524-    9516:    f000 f863     bl    95e0 <_POSIX_API_Initialize>
38525-    951a:    7025          strb    r5, [r4, #0]
38526:  _Thread_Create_idle();
38527-
38528-  /*
38529-   *  Scheduling can properly occur now as long as we avoid
dispatching.
38530-   */
38531-}
38532-    951c:    e8bd 4038     ldmia.w    sp!, {r3, r4, r5, lr}
38533-   *  _Thread_Executing and _Thread_Heir are not set.
38534-   *
38535-   *  At this point all API extensions are in place.  After the call
to
38536:   *  _Thread_Create_idle() _Thread_Executing and _Thread_Heir will
be set.
38537-   */
38538:  _Thread_Create_idle();
38539:    9520:    f002 ba3a     b.w    b998 <_Thread_Create_idle>
38540-    9524:    20004618     .word    0x20004618
38541-    9528:    20004640     .word    0x20004640
38542-    952c:    200041d0     .word    0x200041d0
38543-    9530:    200041e0     .word    0x200041e0
38544-    9534:    2000429c     .word    0x2000429c
38545-    9538:    20004298     .word    0x20004298
38546-
38547-0000953c <rtems_initialize_before_drivers>:
38548-   *  Scheduling can properly occur now as long as we avoid
dispatching.
38549-   */
38550-}
38551-
--
48137-)
48138-{
48139-    b3c4:    4770          bx    lr
48140-    b3c6:    bf00          nop
48141-
48142:0000b3c8 <_Scheduler_default_Start_idle>:
48143-#if defined(RTEMS_SMP)
48144-  Thread_Control *needs_help;
48145-
48146-  needs_help =
48147-#endif
48148-  ( *scheduler->Operations.unblock )( scheduler, the_thread );
48149:    b3c8:    4801          ldr    r0, [pc, #4]    ; (b3d0
<_Scheduler_default_Start_idle+0x8>)
48150-    b3ca:    6943          ldr    r3, [r0, #20]
48151-    b3cc:    4718          bx    r3
48152-    b3ce:    bf00          nop
48153-    b3d0:    0001847c     .word    0x0001847c
48154-
48155-0000b3d4 <_Scheduler_default_Tick>:
48156-  /*
48157-   *  If the thread is not preemptible or is not ready, then
48158-   *  just return.
48159-   */
48160-
48161-  if ( !executing->is_preemptible )
--
49735-    b988:    0001847c     .word    0x0001847c
49736-    b98c:    0001d828     .word    0x0001d828
49737-    b990:    0001d814     .word    0x0001d814
49738-    b994:    0001d878     .word    0x0001d878
49739-
49740:0000b998 <_Thread_Create_idle>:
49741-    cpu
49742-  );
49743-}
49744-
49745:void _Thread_Create_idle( void )
49746-{
49747-    b998:    b5f0          push    {r4, r5, r6, r7, lr}
49748-  return maximum_internal_threads;
49749-}
49750-
49751-RTEMS_INLINE_ROUTINE Thread_Control *_Thread_Internal_allocate( void )
49752-{
49753-  return (Thread_Control *)
49754:    b99a:    4f17          ldr    r7, [pc, #92]    ; (b9f8
<_Thread_Create_idle+0x60>)
49755-    b99c:    b089          sub    sp, #36    ; 0x24
49756-    b99e:    4638          mov    r0, r7
49757-    b9a0:    f7fe ff74     bl    a88c <_Objects_Allocate_unprotected>
49758-  _Thread_Initialize(
49759-    &_Thread_Internal_information,
49760:    idle,
49761-    _Scheduler_Get_by_CPU( cpu ),
49762-    NULL,        /* allocate the stack */
49763:    _Stack_Ensure_minimum(
rtems_configuration_get_idle_task_stack_size() ),
49764:    b9a4:    4e15          ldr    r6, [pc, #84]    ; (b9fc
<_Thread_Create_idle+0x64>)
49765- *
49766- * @return This method returns the minimum stack size;
49767- */
49768-RTEMS_INLINE_ROUTINE uint32_t _Stack_Minimum (void)
49769-{
49770-  return rtems_minimum_stack_size;
49771:    b9a6:    4a16          ldr    r2, [pc, #88]    ; (ba00
<_Thread_Create_idle+0x68>)
49772-    b9a8:    6a73          ldr    r3, [r6, #36]    ; 0x24
49773-    b9aa:    6811          ldr    r1, [r2, #0]
49774-    b9ac:    4605          mov    r5, r0
49775-    b9ae:    428b          cmp    r3, r1
49776-    b9b0:    bf38          it    cc
49777-    b9b2:    460b          movcc    r3, r1
49778-   *  fields not explicitly assigned were explicitly zeroed by
49779-   *  _Workspace_Initialization.
49780-   */
49781:  idle = _Thread_Internal_allocate();
49782-
49783-  _Thread_Initialize(
49784:    b9b4:    4a13          ldr    r2, [pc, #76]    ; (ba04
<_Thread_Create_idle+0x6c>)
49785:static void _Thread_Create_idle_for_cpu( Per_CPU_Control *cpu )
49786-{
49787-  Objects_Name    name;
49788:  Thread_Control *idle;
49789-
49790-  name.name_u32 = _Objects_Build_name( 'I', 'D', 'L', 'E' );
49791:    b9b6:    f8df e058     ldr.w    lr, [pc, #88]    ; ba10
<_Thread_Create_idle+0x78>
49792-   *  fields not explicitly assigned were explicitly zeroed by
49793-   *  _Workspace_Initialization.
49794-   */
49795:  idle = _Thread_Internal_allocate();
49796-
49797-  _Thread_Initialize(
49798-    b9ba:    7811          ldrb    r1, [r2, #0]
49799-    b9bc:    2400          movs    r4, #0
49800-    b9be:    2201          movs    r2, #1
49801-    b9c0:    9300          str    r3, [sp, #0]
49802-    b9c2:    9102          str    r1, [sp, #8]
49803-    b9c4:    f8cd e01c     str.w    lr, [sp, #28]
49804-    b9c8:    4629          mov    r1, r5
49805-    b9ca:    4623          mov    r3, r4
49806-    b9cc:    9203          str    r2, [sp, #12]
49807-    b9ce:    4638          mov    r0, r7
49808-    b9d0:    9401          str    r4, [sp, #4]
49809-    b9d2:    9404          str    r4, [sp, #16]
49810-    b9d4:    9405          str    r4, [sp, #20]
49811-    b9d6:    9406          str    r4, [sp, #24]
49812:    b9d8:    4a0b          ldr    r2, [pc, #44]    ; (ba08
<_Thread_Create_idle+0x70>)
49813-    b9da:    f000 f96d     bl    bcb8 <_Thread_Initialize>
49814-   *             MUST be done before _Thread_Start is invoked.
49815-   */
49816-  cpu->heir      =
49817:  cpu->executing = idle;
49818-
49819-  _Thread_Start(
49820-    b9de:    6a32          ldr    r2, [r6, #32]
49821-  /*
49822-   *  WARNING!!! This is necessary to "kick" start the system and
49823-   *             MUST be done before _Thread_Start is invoked.
49824-   */
49825-  cpu->heir      =
49826:  cpu->executing = idle;
49827:    b9e0:    4e0a          ldr    r6, [pc, #40]    ; (ba0c
<_Thread_Create_idle+0x74>)
49828-
49829-  _Thread_Start(
49830-    b9e2:    9400          str    r4, [sp, #0]
49831-    b9e4:    9601          str    r6, [sp, #4]
49832-    b9e6:    4628          mov    r0, r5
49833-    b9e8:    4621          mov    r1, r4
49834-    b9ea:    4623          mov    r3, r4
49835-  /*
49836-   *  WARNING!!! This is necessary to "kick" start the system and
49837-   *             MUST be done before _Thread_Start is invoked.
49838-   */
49839-  cpu->heir      =
49840:  cpu->executing = idle;
49841-    b9ec:    60b5          str    r5, [r6, #8]
49842-
49843-  /*
49844-   *  WARNING!!! This is necessary to "kick" start the system and
49845-   *             MUST be done before _Thread_Start is invoked.
49846-   */
49847-  cpu->heir      =
49848-    b9ee:    60f5          str    r5, [r6, #12]
49849:  cpu->executing = idle;
49850-
49851-  _Thread_Start(
49852-    b9f0:    f000 fee0     bl    c7b4 <_Thread_Start>
49853-
49854-    if ( _Per_CPU_Is_processor_started( cpu ) ) {
49855:      _Thread_Create_idle_for_cpu( cpu );
49856-    }
49857-  }
49858-}
49859-    b9f4:    b009          add    sp, #36    ; 0x24
49860-    b9f6:    bdf0          pop    {r4, r5, r6, r7, pc}
49861-    b9f8:    200042c0     .word    0x200042c0
49862-    b9fc:    000183c0     .word    0x000183c0
49863-    ba00:    200011c0     .word    0x200011c0
49864-    ba04:    200011bc     .word    0x200011bc
49865-    ba08:    0001847c     .word    0x0001847c
49866-    ba0c:    20004640     .word    0x20004640
49867-    ba10:    49444c45     .word    0x49444c45
--
54093-  const Scheduler_Control *scheduler,
54094-  Thread_Control          *the_thread,
54095-  Per_CPU_Control         *cpu
54096-)
54097-{
54098:  ( *scheduler->Operations.start_idle )( scheduler, the_thread, cpu );
54099-    c7de:    4809          ldr    r0, [pc, #36]    ; (c804
<_Thread_Start+0x50>)
54100-      _Thread_Ready( the_thread );
54101-    } else {
54102-      const Scheduler_Control *scheduler = _Scheduler_Get_by_CPU( cpu
);
54103-
54104-      if ( scheduler != NULL ) {
54105-        the_thread->current_state = STATES_READY;
54106-    c7e0:    2200          movs    r2, #0
54107-    c7e2:    612a          str    r2, [r5, #16]
54108-    c7e4:    6b43          ldr    r3, [r0, #52]    ; 0x34
54109-    c7e6:    4629          mov    r1, r5
54110-    c7e8:    9a05          ldr    r2, [sp, #20]

On Wed, Apr 24, 2019 at 2:59 PM Christian Mauderer <
christian.mauderer at embedded-brains.de> wrote:

> Am 24.04.19 um 02:35 schrieb Jython:
> > yes, I need to do low power for stm32f4
> > will this line work __asm__ volatile ("wfi");?
>
> That line should be correct. Please note that the instruction is already
> used in the armv7 idle thread:
>
>
> https://git.rtems.org/rtems/tree/cpukit/score/cpu/arm/armv7-thread-idle.c#n32
>
> The stm32f4 is a Cortex-M4 so it's quite likely that this routine is
> used. You can check by doing an "arm-rtems5-objdump -dS" on your file
> and search for the idle body.
>
> With kind regards
>
> Christian
>
> >
> >
> > On Tue, Apr 23, 2019 at 10:28 PM Christian Mauderer
> > <christian.mauderer at embedded-brains.de
> > <mailto:christian.mauderer at embedded-brains.de>> wrote:
> >
> >     Am 22.04.19 um 09:47 schrieb Jython:
> >     > HI, ALL!
> >     > wfi
> >
> http://www.keil.com/support/man/docs/armcc/armcc_chr1359125004400.htm
> >     > how can i call the arm __wfi?
> >     >
> >     > _______________________________________________
> >     > users mailing list
> >     > users at rtems.org <mailto:users at rtems.org>
> >     > http://lists.rtems.org/mailman/listinfo/users
> >     >
> >
> >     Hello Jython,
> >
> >     WFI is an assembler instruction. The Keil wrapper isn't available in
> >     gcc. I know of no direct replacement. Most likely you need a gcc
> inline
> >     assembly for that.
> >
> >     May I ask why you would need "wfi"? If you use a operating system,
> the
> >     system typically handles such low level stuff for you. The only
> >     application that springs to mind for that instruction is overwriting
> the
> >     idle loop to save energy.
> >
> >     Best regards
> >
> >     Christian
> >
> >     --
> >     --------------------------------------------
> >     embedded brains GmbH
> >     Herr Christian Mauderer
> >     Dornierstr. 4
> >     D-82178 Puchheim
> >     Germany
> >     email: christian.mauderer at embedded-brains.de
> >     <mailto:christian.mauderer at embedded-brains.de>
> >     Phone: +49-89-18 94 741 - 18
> >     Fax:   +49-89-18 94 741 - 08
> >     PGP: Public key available on request.
> >
> >     Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
> >
>
> --
> --------------------------------------------
> embedded brains GmbH
> Herr Christian Mauderer
> Dornierstr. 4
> D-82178 Puchheim
> Germany
> email: christian.mauderer at embedded-brains.de
> Phone: +49-89-18 94 741 - 18
> Fax:   +49-89-18 94 741 - 08
> PGP: Public key available on request.
>
> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
>
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