Rename tools/Makefile.* to have the .mk extension

This PR renames `tools/Makefile.*` to have the `.mk` extension. This PR also updates `README.md` and other files that references the other files.
Note: Skipped Makefile.host for this PR since it caused failures in CI for the sim build

By using a standard extension for Makefiles (https://www.file-extension.info/format/mk), editors will auto-format files.
This change will also improve developer ergonomics when searching for specific files

Verified locally that build still works, CI will verify more!

Makefile

@@ -40,8 +40,8 @@ DUMMY  := ${shell $(MAKE) -C tools -f Makefile.host incdir \
 # Include the correct Makefile for the selected architecture.
 
 ifeq ($(CONFIG_WINDOWS_NATIVE),y)
-include tools/Makefile.win
+include tools/Win.mk
 else
-include tools/Makefile.unix
+include tools/Unix.mk
 endif
 endif

README.md

@@ -1325,7 +1325,7 @@ damage your configuration (see
   environment:
 
   1. You can run the configuration tool using Cygwin.  However, the
-     Cygwin `Makefile.win` will complain so to do this will, you have
+     Cygwin `Win.mk` will complain so to do this will, you have
      to manually edit the `.config` file:
 
      a. Delete the line: `CONFIG_WINDOWS_NATIVE=y`

boards/arm/stm32/stm32f4discovery/README.txt

@@ -2415,7 +2415,7 @@ Configuration Sub-directories
        usable as of this writing.  The windows native build logic is currently
        separate and must be started by:
 
-        make -f Makefile.win
+        make -f Win.mk
 
       This build:
 

boards/mips/pic32mx/pic32mx-starterkit/README.txt

@@ -522,7 +522,7 @@ On Board Debug Support
   that provides debugger connectivity over USB. The PIC32MX440F512H is hard-wired
   to the PIC32 device to provide two types of protocol translation:
 
-    - I/O pins of PIC32MX440F512H to the ICSP� pins of the PIC32
+    - I/O pins of PIC32MX440F512H to the ICSP™ pins of the PIC32
     - I/O pins of PIC32MX440F512H to the JTAG pins of the PIC32
 
   The PIC32 Ethernet Starter Kit currently uses the JTAG pins of the PIC32 device for
@@ -1038,7 +1038,7 @@ Where <subdir> is one of the following:
        as NSH built-in built in functions.
 
        To use USB device, connect the starter kit to the host using a cable
-       with a Type-B micro-plug to the starter kit�s micro-A/B port J5, located
+       with a Type-B micro-plug to the starter kit's micro-A/B port J5, located
        on the bottom side of the starter kit. The other end of the cable
        must have a Type-A plug. Connect it to a USB host. Jumper JP2 should be
        removed.

boards/mips/pic32mz/pic32mz-starterkit/README.txt

@@ -78,9 +78,9 @@ On Board Debug Support
   The starter kit includes a PIC24FJ256GB106 USB microcontroller that
   provides debugger connectivity over USB. The PIC24FJ256GB106 is hard-wired
   to the PIC32 device to provide protocol translation through the I/O pins
-  of the PIC24FJ256GB106 to the ICSP� pins of the PIC32 device.
+  of the PIC24FJ256GB106 to the ICSP™ pins of the PIC32 device.
 
-  If MPLAB� REAL ICE� or MPLAB ICD 3 is used with the starter kit,
+  If MPLAB® REAL ICE™ or MPLAB ICD 3 is used with the starter kit,
   disconnect the onboard debugger from the PIC32 device by removing the
   jumper JP2. When the on-board debugger is required, replace the jumper
   JP2. When the jumper JP2 is installed, pin 1 must be connected to pin 3

boards/renesas/rx65n/rx65n-grrose/README.txt

@@ -316,7 +316,7 @@ DTC has been tested using RSPI driver.
 
 USB Host Configurations
 --------------------------
-The following configurations need to be enabled for USB Host Mode driver to 
+The following configurations need to be enabled for USB Host Mode driver to
 support USB HID Keyboard class and MSC Class.
 
 CONFIG_USBHOST=y
@@ -326,10 +326,10 @@ CONFIG_EXAMPLES_HIDKBD=y
 
 USB Host Driver Testing
 ------------------------
-The Following Class Drivers were tested as mentioned below : 
+The Following Class Drivers were tested as mentioned below :
 
 - USB HID Keyboard Class
-On the NuttX Console "hidkbd" application was executed 
+On the NuttX Console "hidkbd" application was executed
 
 nsh> hidkbd
 The characters typed from the keyboard were executed correctly.
@@ -338,19 +338,19 @@ The characters typed from the keyboard were executed correctly.
 
 The MSC device is enumerated as sda in /dev directory.
 
-The block device is mounted using the command as mentioned below : 
+The block device is mounted using the command as mentioned below :
 
 mount -t vfat /dev/sda /mnt
 
-The MSC device is mounted in /dev directory 
+The MSC device is mounted in /dev directory
 
 The copy command is executed to test the Read/Write functionality
 
 cp /mnt/<file.txt> /mnt/file_copy.txt
 
 USB Host Hub Configurations
 --------------------------
-The following configurations need to be enabled for USB Host Mode driver to 
+The following configurations need to be enabled for USB Host Mode driver to
 support USB HID Keyboard class and MSC Class.
 
 CONFIG_RX65N_USBHOST=y
@@ -363,22 +363,22 @@ CONFIG_EXAMPLES_HIDKBD=y
 
 USB Host Hub Driver Testing
 ------------------------
-The Following Class Drivers were tested as mentioned below : 
+The Following Class Drivers were tested as mentioned below :
 
 - USB HID Keyboard Class
-On the NuttX Console "hidkbd" application was executed 
+On the NuttX Console "hidkbd" application was executed
 
 nsh> hidkbd
 The characters typed from the keyboard were executed correctly.
 
 - USB MSC Class
 The MSC device is enumerated as sda in /dev directory.
 
-The block device is mounted using the command as mentioned below : 
+The block device is mounted using the command as mentioned below :
 
 mount -t vfat /dev/sda /mnt
 
-The MSC device is mounted in /dev directory 
+The MSC device is mounted in /dev directory
 
 The copy command is executed to test the Read/Write functionality
 
@@ -408,7 +408,7 @@ Alternatively, NuttX binary can be flashed using Renesas flash programmer tool w
 Below are the steps mentioned to flash NuttX binary using Renesas flash programmer tool(RFP).
 
 1.In order to flash using Renesas flash programmer tool, nuttx.mot file should be generated.
-2. Add the following lines in tools/Makefile.unix file :
+2. Add the following lines in tools/Unix.mk file :
 ifeq ($(CONFIG_MOTOROLA_SREC),y)
 	@echo "CP: nuttx.mot"
 	$(Q) $(OBJCOPY) $(OBJCOPYARGS) $(BIN) -O srec -I elf32-rx-be-ns nuttx.mot

boards/renesas/rx65n/rx65n-rsk2mb/README.txt

@@ -290,7 +290,7 @@ DTC has been tested using RSPI driver.
 
 USB Host Configurations
 --------------------------
-The following configurations need to be enabled for USB Host Mode driver to 
+The following configurations need to be enabled for USB Host Mode driver to
 support USB HID Keyboard class and MSC Class.
 
 CONFIG_USBHOST=y
@@ -300,10 +300,10 @@ CONFIG_EXAMPLES_HIDKBD=y
 
 USB Host Driver Testing
 ------------------------
-The Following Class Drivers were tested as mentioned below : 
+The Following Class Drivers were tested as mentioned below :
 
 - USB HID Keyboard Class
-On the NuttX Console "hidkbd" application was executed 
+On the NuttX Console "hidkbd" application was executed
 
 nsh> hidkbd
 The characters typed from the keyboard were executed correctly.
@@ -312,19 +312,19 @@ The characters typed from the keyboard were executed correctly.
 
 The MSC device is enumerated as sda in /dev directory.
 
-The block device is mounted using the command as mentioned below : 
+The block device is mounted using the command as mentioned below :
 
 mount -t vfat /dev/sda /mnt
 
-The MSC device is mounted in /dev directory 
+The MSC device is mounted in /dev directory
 
 The copy command is executed to test the Read/Write functionality
 
 cp /mnt/<file.txt> /mnt/file_copy.txt
 
 USB Host Hub Configurations
 --------------------------
-The following configurations need to be enabled for USB Host Mode driver to 
+The following configurations need to be enabled for USB Host Mode driver to
 support USB HID Keyboard class and MSC Class.
 
 CONFIG_RX65N_USBHOST=y
@@ -337,22 +337,22 @@ CONFIG_EXAMPLES_HIDKBD=y
 
 USB Host Hub Driver Testing
 ------------------------
-The Following Class Drivers were tested as mentioned below : 
+The Following Class Drivers were tested as mentioned below :
 
 - USB HID Keyboard Class
-On the NuttX Console "hidkbd" application was executed 
+On the NuttX Console "hidkbd" application was executed
 
 nsh> hidkbd
 The characters typed from the keyboard were executed correctly.
 
 - USB MSC Class
 The MSC device is enumerated as sda in /dev directory.
 
-The block device is mounted using the command as mentioned below : 
+The block device is mounted using the command as mentioned below :
 
 mount -t vfat /dev/sda /mnt
 
-The MSC device is mounted in /dev directory 
+The MSC device is mounted in /dev directory
 
 The copy command is executed to test the Read/Write functionality
 
@@ -381,7 +381,7 @@ Alternatively, NuttX binary can be flashed using Renesas flash programmer tool w
 Below are the steps mentioned to flash NuttX binary using Renesas flash programmer tool(RFP).
 
 1.In order to flash using Renesas flash programmer tool, nuttx.mot file should be generated.
-2. Add the following lines in tools/Makefile.unix file :
+2. Add the following lines in tools/Unix.mk file :
 ifeq ($(CONFIG_MOTOROLA_SREC),y)
 	@echo "CP: nuttx.mot"
 	$(Q) $(OBJCOPY) $(OBJCOPYARGS) $(BIN) -O srec -I elf32-rx-be-ns nuttx.mot

tools/Makefile.export → tools/Export.mk

@@ -1,5 +1,5 @@
 ############################################################################
-# tools/Makefile.export
+# tools/Export.mk
 #
 # Licensed to the Apache Software Foundation (ASF) under one or more
 # contributor license agreements.  See the NOTICE file distributed with

tools/README.txt

@@ -175,11 +175,11 @@ lowhex.c
 Makefile.[unix|win]
 -----------------
 
-  Makefile.unix is the Makefile used when building NuttX in Unix-like
-  systems.  It is selected from the top-level Makefile.
+  Unix.mk is the Makefile used when building NuttX in Unix-like systems.
+  It is selected from the top-level Makefile.
 
-  Makefile.win is the Makefile used when building natively under
-  Windows.  It is selected from the top-level Makefile.
+  Win.mk is the Makefile used when building natively under Windows.
+  It is selected from the top-level Makefile.
 
 mkconfig.c, cfgdefine.c, and cfgdefine.h
 ----------------------------------------
@@ -191,10 +191,10 @@ mkconfig.c, cfgdefine.c, and cfgdefine.h
   in the top level NuttX directory (See boards/README.txt or
   Documentation/NuttXPortingGuide.html).  The first time you make NuttX,
   the top-level makefile will build the mkconfig executable from mkconfig.c
-  (using Makefile.host).  The top-level Makefile will then execute the
-  mkconfig program to convert the .config file in the top level directory
-  into include/nuttx/config.h.  config.h is a another version of the
-  NuttX configuration that can be included by C files.
+  (using Makefile.host).  The top-level Makefile will then execute the mkconfig
+  program to convert the .config file in the top level directory into
+  include/nuttx/config.h.  config.h is a another version of the NuttX
+  configuration that can be included by C files.
 
 mkconfigvars.sh
 ---------------
@@ -218,14 +218,14 @@ mkconfigvars.sh
     -h
        show this help message and exit
 
-mkexport.sh and Makefile.export
+mkexport.sh and Export.mk
 -------------------------------
 
   These implement part of the top-level Makefile's 'export' target.  That
   target will bundle up all of the NuttX libraries, header files, and the
   startup object into an export-able, binary NuttX distribution.  The
-  Makefile.export is used only by the mkexport.sh script to parse out
-  options from the top-level Make.defs file.
+  Export.mk is used only by the mkexport.sh script to parse out options
+  from the top-level Make.defs file.
 
   USAGE: tools/mkexport.sh [-d] [-z] [-u] -t <top-dir> [-x <lib-ext>] -l "lib1 [lib2 [lib3 ...]]"
 
@@ -253,8 +253,8 @@ mkversion.c, cfgdefine.c, and cfgdefine.h
   When you build NuttX there should be a version file called .version in
   the top level NuttX directory (See Documentation/NuttXPortingGuide.html).
   The first time you make NuttX, the top-level makefile will build the
-  mkversion executable from mkversion.c (using Makefile.host).  The top-
-  level Makefile will then execute the mkversion program to convert the
+  mkversion executable from mkversion.c (using Makefile.host).  The top-level
+  Makefile will then execute the mkversion program to convert the
   .version file in the top level directory into include/nuttx/version.h.
   version.h provides version information that can be included by C files.
 

tools/Makefile.unix → tools/Unix.mk

@@ -1,5 +1,5 @@
 ############################################################################
-# tools/Makefile.unix
+# tools/Unix.mk
 #
 # Licensed to the Apache Software Foundation (ASF) under one or more
 # contributor license agreements.  See the NOTICE file distributed with

tools/Makefile.win → tools/Win.mk

@@ -1,5 +1,5 @@
 ############################################################################
-# tools/Makefile.win
+# tools/Win.mk
 #
 # Licensed to the Apache Software Foundation (ASF) under one or more
 # contributor license agreements.  See the NOTICE file distributed with

tools/mkexport.sh

@@ -163,7 +163,7 @@ cp -a "${TOPDIR}/Make.defs" "${EXPORTDIR}/Make.defs" ||
 
 # Extract information from the Make.defs file.  A Makefile can do this best
 
-${MAKE} -C "${TOPDIR}/tools" -f Makefile.export TOPDIR="${TOPDIR}" EXPORTDIR="${EXPORTDIR}"
+${MAKE} -C "${TOPDIR}/tools" -f Export.mk TOPDIR="${TOPDIR}" EXPORTDIR="${EXPORTDIR}"
 source "${EXPORTDIR}/makeinfo.sh"
 rm -f "${EXPORTDIR}/makeinfo.sh"
 rm -f "${EXPORTDIR}/Make.defs"