Fix minor typos in docs and comments.

ChangeLog

@@ -3335,7 +3335,7 @@
 	  the UDP discovery utility.  Contributed by Max Holtzberg.
 	* mm/README.txt:  Add a new README file.
 	* include/nuttx/usb/usb.h, arch/*/src/*usb.c, and arch/*/src/*otg*.c:
-	  Add hooks to to use common, external DMA buffer allocation
+	  Add hooks to use common, external DMA buffer allocation
 	  implementation.
 	* net/recvfrom.c: Don't block in recvfrom if (1) read-ahead buffering
 	  is enabled and (2) some data was obtained from read-ahead buffers.
@@ -3924,7 +3924,7 @@
 	  locking up the whole system.
 	* sched/sched_waitpid.c:  Use SIGCHLD instead of a semaphore.  This
 	  is a much more spec-compliant implementation.  However, there are
-	  some issues with overruning signals because NuttX does not support
+	  some issues with overrunning signals because NuttX does not support
 	  queueing of signals (POSIX does not require it).  I think it may
 	  need to.
 	* sched/sched_waitid.c and sched_wait.c:  Add support for waitid()
@@ -4442,7 +4442,7 @@
 	  type as the second parameter (2013-03-23).
 	* arch/arm/src/lm, kinetis, lpc43, and nuc1xx:  Add kernel build
 	  support to all ARMv7-M and ARMv6-M chips.  There are no
-	  configurations in place to to verify these additions!
+	  configurations in place to verify these additions!
 	  (2013-03-24).
 	* arch/arm/src/lm/lm_gpio.h:  Correct typos in alternate function
 	  definitions (2013-03-24).
@@ -8429,7 +8429,7 @@
 	  addresses to physical addresses, and vice versa (2104-9-7).
 	* SAM3X/Arduino Due: Fix typo in sam3x_periphclks.h; add SCLK
 	  definitions to board.h header file.  From Fabien Comte (2014-9-8).
-	* Several pthread interfaces: Add const storage class to to phthread
+	* Several pthread interfaces: Add const storage class to the phthread
 	  parameters.  From Freddie Chopin (2014-9-8).
 	* libc/math: Corrected atan2 implementations from Denis Arnst (2014-9-8).
 	* sama5d4-ek/knsh:  Rename the kernel configuration to knsh to better
@@ -12026,9 +12026,9 @@
 	* STM32F7: Add SPI, I2C, and ADC drivers.  From Lok Tep (2016-06-15).
 	* err(), warn(), info(), and alert() renamed to include leading '_'.
 	  This was done to avoid some naming collisions (2-06-16
-	* STM32: Move backup domain reset to to earlier in the initialization
+	* STM32: Move backup domain reset to earlier in the initialization
 	  sequence (stm32_rcc.c() in order to avoid disabling LSE during RTC
-	  initialiation.  From Alan Carvalho de Assis (2016-06-16).
+	  initialization.  From Alan Carvalho de Assis (2016-06-16).
 	* SYSLOG: syslog() will now automatically redirect output to lowsyslog()
 	  if called from an interrupt handler (2016-06-16).
 	* STM32: When configuring a GPIO via stm32_configgpio() the function
@@ -16638,7 +16638,7 @@
 	  because current data structures do not support it (2017-08-29).
 	* Networking:  Clean up some naming that has bothered me for a long
 	  time... There are no interrupts and no interrupt handlers in the
-	  network.  There are events and event handler (there used to to be
+	  network.  There are events and event handler (there used to be
 	  interrupt logic in there years ago but that is long, long gone)
 	  (2017-08-29).
 	* configs: update STM32L4 configs for ADC changes.  From Juha Niskanen
@@ -24932,7 +24932,7 @@
 	* arch/arm/src/am335x/am335x_sysclk.c:  Add a function to return a
 	  frequency of the system clock.  From Gregory Nutt (2019-07-08).
 	* arch/arm/src/am335x/am335x_lcdc.c:  Add logic to get/set the module
-	  reference clock.  Still one more clocking interface to to.  From Gregory
+	  reference clock.  Still one more clocking interface to do.  From Gregory
 	  Nutt (2019-07-08).
 	* configs/beaglebone-black/lcd/defconfig:  Add a configuration for bringing
 	  up the LCDC driver.  From Gregory Nutt (2019-07-08).

Documentation/NXGraphicsSubsystem.html

@@ -1037,7 +1037,7 @@ int nxmu_start(int display, int plane);
 </p>
 <p>
   <b>Returned Value:</b>
-  On success zero (<code>OK</code) is returned; -1 (<code>ERROR</code>) is returned on failure with the <code>errno</code> variable to to indicate the nature of the failure.
+  On success zero (<code>OK</code) is returned; -1 (<code>ERROR</code>) is returned on failure with the <code>errno</code> variable set to indicate the nature of the failure.
 </p>
 
 <h3>2.3.4 <a name="nxcallbacks">NX Server Callbacks</a></h3>
@@ -4088,7 +4088,7 @@ enum nx_fontid_e
 </ol>
 <p>
   New Add the font to the NX build system.
-  There are several files that you have to modify to to this.
+  There are several files that you have to modify to do this.
   Look how the build system uses the font CONFIG_NXFONT_SANS23X27 for examaples:
 </p>
 <ol start="5">

Documentation/NuttxPortingGuide.html

@@ -3717,7 +3717,7 @@ void lpwork_restorepriority(uint8_t reqprio);
 </ul>
 <p><b>Description</b>:</p>
 <ul>
-  After an address environment has been established for a task (via <code>up_addrenv_create())</code>, this function may be called to to instantiate that address environment in the virtual address space.
+  After an address environment has been established for a task (via <code>up_addrenv_create())</code>, this function may be called to instantiate that address environment in the virtual address space.
   This might be necessary, for example, to load the code for the task from a file or to access address environment private data.
 </ul>
 <p><b>Input Parameters</b>:</p>
@@ -3742,7 +3742,7 @@ void lpwork_restorepriority(uint8_t reqprio);
 <p><b>Description</b>:</p>
 <ul>
   After an address environment has been temporarily instantiated by <code>up_addrenv_select</code>,
-  this function may be called to to restore the original address environment.
+  this function may be called to restore the original address environment.
 </ul>
 <p><b>Input Parameters</b>:</p>
 <ul>
@@ -4161,7 +4161,7 @@ void nxsched_timer_expiration(void);
 <p><b>Returned Value</b>:</p>
 <ul>
   On success zero (<code>OK</code>) is returned;
-  -1 (<code>ERROR</code>) is returned on failure with the <code>errno</code> variable to to indicate the nature of the failure.
+  -1 (<code>ERROR</code>) is returned on failure with the <code>errno</code> variable set to indicate the nature of the failure.
 </ul>
 
 <h4><a name="boardsmp">4.10 Symmetric Multiprocessing (SMP) Application Interface</a></h4>

Documentation/NuttxUserGuide.html

@@ -484,7 +484,7 @@ int task_delete(pid_t pid);
 </p>
 <p>
   The logic in this function only deletes non-running tasks.
-  If the  <code>pid</code> parameter refers to to the currently runing task, then processing is redirected to <code>exit()</code>.
+  If the <code>pid</code> parameter refers to the currently running task, then processing is redirected to <code>exit()</code>.
   This can only happen if a task calls <code>task_delete()</code> in order to delete itself.
 </p>
 <p>

ReleaseNotes

@@ -4295,8 +4295,8 @@ Additional new features and extended functionality:
     * STM32:
 
       - Added an option to conditionally disable the "wfi" sleep mode.  This
-        is needed with certain JTAG debuggers to to prevent the debug
+        is needed with certain JTAG debuggers to prevent the debug session
-        session from begin disconnected (from Ken Pettit).
+        from being disconnected (from Ken Pettit).
       - Added support for the STM32L (STM32L15X/STM32L16x) family.
       - Added STM32F103C4 and F103C8 chip support (from Laurent Latil).
       - Added a new interface function, stm32_dmacapable() that can be used
@@ -6060,7 +6060,7 @@ Bugfixes (see the ChangeLog for details).  Some of these are very important:
     * NuttShell (NSH):
 
       - Use strncpy vs strcpy in the Telnet console logic to avoid
-        overruning the username and password buffers (from Bertold Van den
+        overrunning the username and password buffers (from Bertold Van den
         Bergh).
       - Add a newline after printing the file in the 'cat' command.  This
         prevents the NSH prompt from be in the same line as the final line
@@ -11651,7 +11651,7 @@ detailed bugfix information):
         From Konstantin Berezenko.
       - STM32 F1-F4: Correct the CAN2 RX IRQ number for stm32f10xx chips.
         From Konstantin Berezenko.
-      - STM32 F1-F4: Move backup domain reset to to earlier in the
+      - STM32 F1-F4: Move backup domain reset to earlier in the
         initialization sequence (stm32_rcc.c() in order to avoid disabling
         LSE during RTC initialiation.  From Alan Carvalho de Assis.
       - STM32 F1-F4: When configuring a GPIO via stm32_configgpio() the

TODO

@@ -1218,7 +1218,7 @@ o C++ Support
                   one task can effect another task. There can only one
                   uClibc++ state and it will be shared by all tasks. uClibc++
                   apparently relies on global instances (at least for cin and
-                  cout) there is no way to to have any unique state for any
+                  cout) there is no way to have any unique state for any
                   "task group".
 
                   [NuttX does not support processes because in order to have

arch/arm/src/armv6-m/Toolchain.defs

@@ -186,6 +186,6 @@ ifeq ($(CONFIG_ARMV6M_TOOLCHAIN),GNU_EABIW)
 endif
 
 # Individual tools may limit the optimizatin level but, by default, the
-# optimization level will be set to to -Os
+# optimization level will be set to -Os
 
 MAXOPTIMIZATION ?= -Os

arch/arm/src/armv6-m/up_svcall.c

@@ -222,7 +222,7 @@ int up_svcall(int irq, FAR void *context, FAR void *arg)
        *
        * In this case, we do both: We save the context registers to the save
        * register area reference by the saved contents of R1 and then set
-       * CURRENT_REGS to to the save register area referenced by the saved
+       * CURRENT_REGS to the save register area referenced by the saved
        * contents of R2.
        */
 

arch/arm/src/armv7-a/arm_addrenv.c

@@ -482,7 +482,7 @@ ssize_t up_addrenv_heapsize(FAR const group_addrenv_t *addrenv)
  *
  * Description:
  *   After an address environment has been established for a task group (via
- *   up_addrenv_create().  This function may be called to to instantiate
+ *   up_addrenv_create().  This function may be called to instantiate
  *   that address environment in the virtual address space.  this might be
  *   necessary, for example, to load the code for the task group from a file or
  *   to access address environment private data.
@@ -620,7 +620,7 @@ int up_addrenv_select(FAR const group_addrenv_t *addrenv,
  *
  * Description:
  *   After an address environment has been temporarily instantiated by
- *   up_addrenv_select(), this function may be called to to restore the
+ *   up_addrenv_select(), this function may be called to restore the
  *   original address environment.
  *
  * Input Parameters:

arch/arm/src/armv7-m/up_svcall.c

@@ -219,7 +219,7 @@ int up_svcall(int irq, FAR void *context, FAR void *arg)
        *
        * In this case, we do both: We save the context registers to the save
        * register area reference by the saved contents of R1 and then set
-       * CURRENT_REGS to to the save register area referenced by the saved
+       * CURRENT_REGS to the save register area referenced by the saved
        * contents of R2.
        */
 

arch/arm/src/c5471/c5471_watchdog.c

@@ -76,7 +76,7 @@
 #define CLOCK_KHZ              47500
 #define CLOCK_MHZx2            95
 
-/* Macros to manage access to to watchdog timer macros */
+/* Macros to manage access to the watchdog timer */
 
 #define c5471_wdt_cntl  (*(volatile uint32_t*)C5471_TIMER0_CTRL)
 #define c5471_wdt_count (*(volatile uint32_t*)C5471_TIMER0_CNT)

arch/arm/src/dm320/dm320_timerisr.c

@@ -82,7 +82,7 @@
 /* System Timer
  *
  * Timer0 is dedicated as the system timer.  The rate of system timer
- * interrupts is assumed to to 10MS per tick / 100Hz. The following
+ * interrupts is assumed to be 10MS per tick / 100Hz. The following
  * register settings are used for timer 0
  *
  * System clock formula:

arch/arm/src/imx1/imx_spi.c

@@ -395,7 +395,7 @@ static int spi_performtx(struct imx_spidev_s *priv)
                priv->txword(priv);
             }
 
-          /* Update the count of words to to transferred */
+          /* Update the count of words to be transferred */
 
           priv->ntxwords -= ntxd;
         }

arch/arm/src/imx6/imx_ecspi.c

@@ -520,7 +520,7 @@ static int spi_performtx(struct imx_spidev_s *priv)
                priv->txword(priv);
             }
 
-          /* Update the count of words to to transferred */
+          /* Update the count of words to be transferred */
 
           priv->ntxwords -= ntxd;
         }

arch/arm/src/kinetis/kinetis_rtc.c

@@ -320,7 +320,7 @@ int up_rtc_initialize(void)
 #ifdef KINETIS_RTC_GEN2
       /* Check if the one-time initialization of the RTC has already been
        * performed. We can determine this by checking if the magic number
-       * has been writing to to back-up date register DR0.
+       * has been written to the back-up date register DR0.
        */
 
       regval = getreg32(KINETIS_RTC_MCLR);

arch/arm/src/lpc43xx/lpc43_ethernet.c

@@ -870,7 +870,7 @@ static inline uint8_t *lpc43_allocbuffer(FAR struct lpc43_ethmac_s *priv)
 
 static inline void lpc43_freebuffer(FAR struct lpc43_ethmac_s *priv, uint8_t *buffer)
 {
-  /* Free the buffer by adding it to to the end of the free buffer list */
+  /* Free the buffer by adding it to the end of the free buffer list */
 
   sq_addlast((FAR sq_entry_t *)buffer, &priv->freeb);
 }

arch/arm/src/nuc1xx/nuc_lowputc.c

@@ -332,7 +332,7 @@ void nuc_lowputc(uint32_t ch)
 
   nuc_console_ready();
 
-  /* Then write the character to to the TX FIFO */
+  /* Then write the character to the TX FIFO */
 
   putreg32(ch, NUC_CONSOLE_BASE + NUC_UART_THR_OFFSET);
 #endif /* HAVE_SERIAL_CONSOLE */

arch/arm/src/sama5/sam_tsd.c

@@ -582,7 +582,7 @@ static void sam_tsd_bottomhalf(void *arg)
     {
       /* If we have not yet processed the last pen up event, then we
        * cannot handle this pen down event. We will have to discard it.  That
-       * should be okay because we will set the timer to to sample again
+       * should be okay because we will set the timer to sample again
        * a little later.  NOTE that pen interrupts are not re-enabled in
        * this case; we rely on the timer expiry to get us going again.
        */

arch/arm/src/samd5e5/sam_clockconfig.c

@@ -828,7 +828,7 @@ static void sam_dfll_gclkready(const struct sam_dfll_config_s *config)
     {
     }
 
-  /* Set the source of GCLK0 to to the configured source. */
+  /* Set the source of GCLK0 to the configured source. */
 
   regval32  = getreg32(SAM_GCLK_GENCTRL(0));
   regval32 &= ~GCLK_GENCTRL_SRC_MASK;

arch/arm/src/stm32/stm32_eth.c

@@ -978,7 +978,7 @@ static inline uint8_t *stm32_allocbuffer(FAR struct stm32_ethmac_s *priv)
 
 static inline void stm32_freebuffer(FAR struct stm32_ethmac_s *priv, uint8_t *buffer)
 {
-  /* Free the buffer by adding it to to the end of the free buffer list */
+  /* Free the buffer by adding it to the end of the free buffer list */
 
   sq_addlast((FAR sq_entry_t *)buffer, &priv->freeb);
 }

arch/arm/src/stm32/stm32_otgfshost.c

@@ -2001,7 +2001,7 @@ static ssize_t stm32_in_transfer(FAR struct stm32_usbhost_s *priv, int chidx,
       else
         {
           /* Successfully received another chunk of data... add that to the
-           * runing total.  Then continue reading until we read 'buflen'
+           * running total.  Then continue reading until we read 'buflen'
            * bytes of data or until the devices NAKs (implying a short
            * packet).
            */

arch/arm/src/stm32/stm32_otghshost.c

@@ -2006,7 +2006,7 @@ static ssize_t stm32_in_transfer(FAR struct stm32_usbhost_s *priv, int chidx,
       else
         {
           /* Successfully received another chunk of data... add that to the
-           * runing total.  Then continue reading until we read 'buflen'
+           * running total.  Then continue reading until we read 'buflen'
            * bytes of data or until the devices NAKs (implying a short
            * packet).
            */

arch/arm/src/stm32/stm32_rtcc.c

@@ -638,7 +638,7 @@ int up_rtc_initialize(void)
 
   /* Check if the one-time initialization of the RTC has already been
    * performed. We can determine this by checking if the magic number
-   * has been writing to to back-up date register DR0.
+   * has been written to the back-up date register DR0.
    */
 
   if (regval != RTC_MAGIC && regval != RTC_MAGIC_TIME_SET)

arch/arm/src/stm32/stm32f40xxx_rtcc.c

@@ -1035,7 +1035,7 @@ int up_rtc_initialize(void)
 
   /* Check if the one-time initialization of the RTC has already been
    * performed. We can determine this by checking if the magic number
-   * has been writing to to back-up date register DR0.
+   * has been written to the back-up date register DR0.
    */
 
   if (regval != RTC_MAGIC && regval != RTC_MAGIC_TIME_SET)

arch/arm/src/stm32f7/stm32_ethernet.c

@@ -993,7 +993,7 @@ static inline uint8_t *stm32_allocbuffer(struct stm32_ethmac_s *priv)
 
 static inline void stm32_freebuffer(struct stm32_ethmac_s *priv, uint8_t *buffer)
 {
-  /* Free the buffer by adding it to to the end of the free buffer list */
+  /* Free the buffer by adding it to the end of the free buffer list */
 
   sq_addlast((sq_entry_t *)buffer, &priv->freeb);
 }

arch/arm/src/stm32f7/stm32_otghost.c

@@ -1999,7 +1999,7 @@ static ssize_t stm32_in_transfer(FAR struct stm32_usbhost_s *priv, int chidx,
       else
         {
           /* Successfully received another chunk of data... add that to the
-           * runing total.  Then continue reading until we read 'buflen'
+           * running total.  Then continue reading until we read 'buflen'
            * bytes of data or until the devices NAKs (implying a short
            * packet).
            */

arch/arm/src/stm32f7/stm32_rtc.c

@@ -1047,7 +1047,7 @@ int up_rtc_initialize(void)
 
   /* Check if the one-time initialization of the RTC has already been
    * performed. We can determine this by checking if the magic number
-   * has been writing to to back-up date register DR0.
+   * has been written to the back-up date register DR0.
    */
 
   if (regval != RTC_MAGIC && regval != RTC_MAGIC_TIME_SET)

arch/arm/src/stm32h7/stm32_ethernet.c

@@ -994,7 +994,7 @@ static inline uint8_t *stm32_allocbuffer(struct stm32_ethmac_s *priv)
 static inline void stm32_freebuffer(struct stm32_ethmac_s *priv,
                                     uint8_t *buffer)
 {
-  /* Free the buffer by adding it to to the end of the free buffer list */
+  /* Free the buffer by adding it to the end of the free buffer list */
 
   sq_addlast((sq_entry_t *)buffer, &priv->freeb);
 }

arch/arm/src/stm32h7/stm32_otghost.c

@@ -2004,7 +2004,7 @@ static ssize_t stm32_in_transfer(FAR struct stm32_usbhost_s *priv, int chidx,
       else
         {
           /* Successfully received another chunk of data... add that to the
-           * runing total.  Then continue reading until we read 'buflen'
+           * running total.  Then continue reading until we read 'buflen'
            * bytes of data or until the devices NAKs (implying a short
            * packet).
            */

arch/arm/src/stm32h7/stm32_rtc.c

@@ -1047,7 +1047,7 @@ int up_rtc_initialize(void)
 
   /* Check if the one-time initialization of the RTC has already been
    * performed. We can determine this by checking if the magic number
-   * has been writing to to back-up date register DR0.
+   * has been written to back-up date register DR0.
    */
 
   if (regval != RTC_MAGIC && regval != RTC_MAGIC_TIME_SET)

arch/arm/src/stm32l4/stm32l4_otgfshost.c

@@ -2005,7 +2005,7 @@ static ssize_t stm32l4_in_transfer(FAR struct stm32l4_usbhost_s *priv,
       else
         {
           /* Successfully received another chunk of data... add that to the
-           * runing total.  Then continue reading until we read 'buflen'
+           * running total.  Then continue reading until we read 'buflen'
            * bytes of data or until the devices NAKs (implying a short
            * packet).
            */

arch/arm/src/stm32l4/stm32l4x3xx_rcc.c

@@ -950,7 +950,7 @@ static inline void rcc_enableperipherals(void)
   rcc_enableapb2();
 
 #ifdef STM32L4_USE_HSI48
-  /* Enable HSI48 clocking to to support USB transfers or RNG */
+  /* Enable HSI48 clocking to support USB transfers or RNG */
 
   stm32l4_enable_hsi48(STM32L4_HSI48_SYNCSRC);
 #endif

arch/arm/src/stm32l4/stm32l4x6xx_rcc.c

@@ -1018,7 +1018,7 @@ static inline void rcc_enableperipherals(void)
   rcc_enableapb2();
 
 #ifdef STM32L4_USE_HSI48
-  /* Enable HSI48 clocking to to support USB transfers or RNG */
+  /* Enable HSI48 clocking to support USB transfers or RNG */
 
   stm32l4_enable_hsi48(STM32L4_HSI48_SYNCSRC);
 #endif

arch/arm/src/stm32l4/stm32l4xrxx_rcc.c

@@ -995,7 +995,7 @@ static inline void rcc_enableperipherals(void)
   rcc_enableapb2();
 
 #ifdef STM32L4_USE_HSI48
-  /* Enable HSI48 clocking to to support USB transfers or RNG */
+  /* Enable HSI48 clocking to support USB transfers or RNG */
 
   stm32l4_enable_hsi48(STM32L4_HSI48_SYNCSRC);
 #endif

arch/arm/src/str71x/str71x_head.S

@@ -260,7 +260,7 @@
  * Description:
  *   The EIC is initialized for use with NuttX.  This initialization does not
  *   take advantage of the high performance capabilities of the EIC.  Instead,
- *   The EIC is only used to to provide NuttX IRQ numbers.  Here is what is
+ *   The EIC is only used to provide NuttX IRQ numbers.  Here is what is
  *   done:
  *
  *     IRQs and FIQs are disabled

arch/arm/src/tiva/common/tiva_ssi.c

@@ -699,7 +699,7 @@ static int ssi_performtx(struct tiva_ssidev_s *priv)
                priv->txword(priv);
             }
 
-          /* Update the count of words to to transferred */
+          /* Update the count of words to be transferred */
 
           priv->ntxwords -= ntxd;
         }

arch/arm/src/tiva/tm4c/tm4c_ethernet.c

@@ -978,7 +978,7 @@ static inline uint8_t *tiva_allocbuffer(FAR struct tiva_ethmac_s *priv)
 
 static inline void tiva_freebuffer(FAR struct tiva_ethmac_s *priv, uint8_t *buffer)
 {
-  /* Free the buffer by adding it to to the end of the free buffer list */
+  /* Free the buffer by adding it to the end of the free buffer list */
 
   sq_addlast((FAR sq_entry_t *)buffer, &priv->freeb);
 }

arch/mips/src/mips32/up_swint0.c

@@ -183,8 +183,8 @@ int up_swint0(int irq, FAR void *context, FAR void *arg)
        *   R6 = restoreregs
        *
        * In this case, we save the context registers to the save register
-       * area reference by the saved contents of R5 and then set
+       * area referenced by the saved contents of R5 and then set
-       * g_current_regs to to the save register area referenced by the saved
+       * g_current_regs to the save register area referenced by the saved
        * contents of R6.
        */
 

arch/misoc/src/lm32/lm32_swint.c

@@ -184,8 +184,8 @@ int lm32_swint(int irq, FAR void *context, FAR void *arg)
        *   A2 = restoreregs
        *
        * In this case, we save the context registers to the save register
-       * area reference by the saved contents of R5 and then set
+       * area referenced by the saved contents of R5 and then set
-       * g_current_regs to to the save register area referenced by the saved
+       * g_current_regs to the save register area referenced by the saved
        * contents of R6.
        */
 

arch/misoc/src/minerva/minerva_swint.c

@@ -176,9 +176,9 @@ int minerva_swint(int irq, FAR void *context, FAR void *arg)
       /* A0=SYS_switch_context: This a switch context command: void
        * up_switchcontext(uint32_t *saveregs, uint32_t *restoreregs); At this
        * point, the following values are saved in context: A0 =
-       * SYS_switch_context A1 = saveregs A2 = restoreregs In this case, we
+       * SYS_switch_context A1 = saveregs A2 = restoreregs. In this case, we
-       * save the context registers to the save register area reference by the
+       * save the context registers to the save register area referenced by
-       * saved contents of R5 and then set g_current_regs to to the save
+       * the saved contents of R5 and then set g_current_regs to the save
        * register area referenced by the saved contents of R6.
        */
 

arch/risc-v/src/rv32im/Toolchain.defs

@@ -105,8 +105,8 @@ ifeq ($(CONFIG_RISCV_TOOLCHAIN),GNU_RISCY)
   ARCHCPUFLAGS = -march=rv32imcxgap8 -mPE=8 -mFC=1 -D__riscv__ -D__pulp__ -D__GAP8__
 endif
 
-# Individual tools may limit the optimizatin level but, by default, the
+# Individual tools may limit the optimization level but, by default, the
-# optimization level will be set to to -Os
+# optimization level will be set to -Os
 
 ifeq ($(CONFIG_DEBUG_SYMBOLS),)
 MAXOPTIMIZATION ?= -Os

arch/risc-v/src/rv32im/up_swint.c

@@ -181,8 +181,8 @@ int up_swint(int irq, FAR void *context, FAR void *arg)
        *   A2 = restoreregs
        *
        * In this case, we save the context registers to the save register
-       * area reference by the saved contents of R5 and then set
+       * area referenced by the saved contents of R5 and then set
-       * g_current_regs to to the save register area referenced by the saved
+       * g_current_regs to the save register area referenced by the saved
        * contents of R6.
        */
 

arch/z16/src/z16f/z16f_timerisr.c

@@ -148,7 +148,7 @@ void z16_timer_initialize(void)
    *  scaledfreq   = 20,000,000 / 100
    *               = 200,000
    *  divisor      = ((18,432,000 / 100) >> 16) + 1
-   *               = 3 -> 4 (need to to up to next power of two)
+   *               = 3 -> 4 (need to go up to next power of two)
    *  reload_value = 20,000,000 / 100 / 4
    *               = 56,080
    */

arch/z80/src/z180/z180_mmu.c

@@ -419,7 +419,7 @@ ssize_t up_addrenv_heapsize(FAR const group_addrenv_t *addrenv)
  *
  * Description:
  *   After an address environment has been established for a task (via
- *   up_addrenv_create()), this function may be called to to instantiate
+ *   up_addrenv_create()), this function may be called to instantiate
  *   that address environment in the virtual address space.  This might be
  *   necessary, for example, to load the code for the task from a file or
  *   to access address environment private data.
@@ -463,8 +463,8 @@ int up_addrenv_select(FAR const group_addrenv_t *addrenv,
  * Name: up_addrenv_restore
  *
  * Description:
- *   After an address environment has been temporarilty instantiated by
+ *   After an address environment has been temporarily instantiated by
- *   up_addrenv_select, this function may be called to to restore the
+ *   up_addrenv_select, this function may be called to restore the
  *   original address environment.
  *
  * Input Parameters:

audio/pcm_decode.c

@@ -1335,7 +1335,7 @@ static void pcm_callback(FAR void *arg, uint16_t reason,
 
   DEBUGASSERT(priv && priv->export.upper);
 
-  /* The buffer belongs to to an upper level.  Just forward the event to
+  /* The buffer belongs to an upper level.  Just forward the event to
    * the next level up.
    */
 

boards/Kconfig

@@ -1871,7 +1871,7 @@ config ARCH_BOARD_CUSTOM_DIR
 		to also tell the build system where it can find the board directory
 		for the custom board.
 
-		In this case, the board directory is assume to lie outside the
+		In this case, the board directory is assumed to lie outside the
 		NuttX directory.  The provided path must then be a full, absolute
 		path to some location outside of the NuttX source tree (like
 		"~/projects/myboard").

boards/arm/cxd56xx/spresense/src/cxd56_ioctl.c

@@ -80,7 +80,7 @@
  *
  * Returned Value:
  *   On success zero (OK) is returned; -1 (ERROR) is returned on failure
- *   with the errno variable to to indicate the nature of the failure.
+ *   with the errno variable to indicate the nature of the failure.
  *
  ****************************************************************************/
 

boards/arm/stm32/mikroe-stm32f4/src/stm32_touchscreen.c

@@ -677,7 +677,7 @@ static int tc_waitsample(FAR struct tc_dev_s *priv,
 {
   int ret;
 
-  /* Pre-emption must be disabled when this is called to to prevent sampled
+  /* Pre-emption must be disabled when this is called to prevent sampled
    * data from changing until it has been reported.
    */
 

boards/arm/stm32/stm32f4discovery/README.txt

@@ -1383,7 +1383,7 @@ Configuration Sub-directories
        executable in PATH variable (see apps/examples/README.txt)
 
     5. This configuration can be extended to use the hello++4 example and to
-       build uClibc with the following additions to to the configuration file
+       build uClibc with the following additions to the configuration file
        (from Leo aloe3132):
 
        CONFIG_C99_BOOL8=y
@@ -1439,7 +1439,7 @@ Configuration Sub-directories
 
        You may also want to reconfigure the serial console to USART1.
 
-    2. The HCI UART is assume to connect to the UART3 on the following pins:
+    2. The HCI UART is assumed to connect to the UART3 on the following pins:
 
          USART3 TX :  PB10
          USART3 RX :  PB11

boards/boardctl.c

@@ -89,7 +89,7 @@
  *
  * Returned Value:
  *   On success zero (OK) is returned; -1 (ERROR) is returned on failure
- *   with the errno variable to to indicate the nature of the failure.
+ *   with the errno variable to indicate the nature of the failure.
  *
  ****************************************************************************/
 
@@ -258,7 +258,7 @@ static inline int boardctl_usbdevctrl(FAR struct boardioc_usbdev_ctrl_s *ctrl)
  *
  * Returned Value:
  *   On success zero (OK) is returned; -1 (ERROR) is returned on failure
- *   with the errno variable to to indicate the nature of the failure.
+ *   with the errno variable to indicate the nature of the failure.
  *
  ****************************************************************************/