Add Windows build art(e|i)facts (#561)

This includes:
 * Cmake clean up - thanks @Qyriad
 * Windows binaries saved after each appveyor build
 * A bump to the Visual Studio version that we use to build it
 * An appveyor cygwin script for building firmware, it doesn't work but it seems like someone might pick it up and make it work, or blow it away if we switch to Travis firmware artefacts

appveyor.yml

@@ -1,4 +1,4 @@
-os: Visual Studio 2015
+os: Visual Studio 2017
 clone_depth: 1
 
 configuration:
@@ -7,18 +7,25 @@ configuration:
 init:
   - C:\"Program Files (x86)"\"Microsoft Visual Studio 14.0"\VC\vcvarsall.bat %PLATFORM%
 install:
+  # Dependencies for libHackRF
   - appveyor DownloadFile "https://github.com/libusb/libusb/releases/download/v1.0.22/libusb-1.0.22.7z" -FileName "C:\libusb.7z"
   - 7z x -y "C:\libusb.7z" -o"C:\libusb"
   - appveyor DownloadFile "http://mirrors.kernel.org/sourceware/pthreads-win32/pthreads-w32-2-9-1-release.zip" -FileName "C:\pthreads-w32-release.zip"
   - 7z x -y "C:\pthreads-w32-release.zip" -o"C:\pthreads"
   - appveyor DownloadFile "http://ftp.gnome.org/pub/gnome/binaries/win32/dependencies/pkg-config_0.26-1_win32.zip" -FileName "C:\pkg-config_win32.zip"
   - 7z x -y "C:\pkg-config_win32.zip" -o"C:\pkg-config"
+  # FFTW for hackrf_sweep
   - curl -fsS -o "C:\fftw-3.3.5.zip" "ftp://ftp.fftw.org/pub/fftw/fftw-3.3.5-dll64.zip"
   - 7z x -y "C:\fftw-3.3.5.zip" -o"C:\fftw"
   - cd c:\fftw
   - ps: lib /machine:x64 /def:libfftw3f-3.def
+  # ARM GCC for firmware builds
+  # - appveyor DownloadFile "https://developer.arm.com/-/media/Files/downloads/gnu-rm/6-2017q2/gcc-arm-none-eabi-6-2017-q2-update-win32.zip" -FileName "C:\gcc-arm-none-eabi-win32.zip"
+  # - 7z x -y "C:\gcc-arm-none-eabi-win32.zip" -o"C:\gcc-arm-none-eabi"
+  # - set PATH=%PATH%;c:\gcc-arm-none-eabi\bin
 
 build_script:
+  # Host library and tools
   - mkdir c:\projects\hackrf\host\build
   - cd c:\projects\hackrf\host\build
   - cmake -G "Visual Studio 14 2015 Win64" \
@@ -31,3 +38,15 @@ build_script:
     -DFFTW_LIBRARIES=C:\fftw\libfftw3f-3.lib \
     ..
   - msbuild HackRF.sln /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll"
+  # Firmware
+  # - cd c:\projects\hackrf\
+  # - git submodule init
+  # - git submodule update
+  # - '%CYG_BASH% -lc "cd $APPVEYOR_BUILD_FOLDER && firmware/appveyor.sh"'
+
+after_build:
+  - 7z a %APPVEYOR_BUILD_FOLDER%\HackRF-Windows-%APPVEYOR_REPO_COMMIT%.zip %APPVEYOR_BUILD_FOLDER%\host\build\libhackrf\src\Release\* %APPVEYOR_BUILD_FOLDER%\host\build\hackrf-tools\src\Release\* 
+
+artifacts:
+  - path: HackRF-Windows-%APPVEYOR_REPO_COMMIT%.zip
+    name: HackRF-Windows-%APPVEYOR_REPO_COMMIT%

firmware/CMakeLists.txt

@@ -20,7 +20,7 @@
 
 # Top directory CMake project for HackRF firmware
 
-cmake_minimum_required(VERSION 2.8.9)
+cmake_minimum_required(VERSION 3.1.3)
 set(CMAKE_TOOLCHAIN_FILE toolchain-arm-cortex-m.cmake)
 
 project (hackrf_firmware_all C)

firmware/appveyor.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+
+/usr/bin/env python -m ensurepip
+/usr/bin/env python -m pip install pyyaml
+
+cd firmware/libopencm3
+export SRCLIBDIR='c:\projects\hackrf\firmware\libopencm3\lib\'
+make lib/lpc43xx/m0
+make lib/lpc43xx/m4
+cd ..
+mkdir build-hackrf-one
+cd build-hackrf-one
+cmake -G "Unix Makefiles" ..
+make VERBOSE=1

firmware/blinky/CMakeLists.txt

@@ -19,7 +19,7 @@
 # Boston, MA 02110-1301, USA.
 #
 
-cmake_minimum_required(VERSION 2.8.9)
+cmake_minimum_required(VERSION 3.1.3)
 set(CMAKE_TOOLCHAIN_FILE ../toolchain-arm-cortex-m.cmake)
 
 project(blinky C)

firmware/hackrf-common.cmake

@@ -70,7 +70,7 @@ SET(LDSCRIPT_M4_DFU "-T${PATH_HACKRF_FIRMWARE_COMMON}/${MCU_PARTNO}_M4_memory.ld
 
 SET(LDSCRIPT_M0 "-T${PATH_HACKRF_FIRMWARE_COMMON}/LPC43xx_M0_memory.ld -Tlibopencm3_lpc43xx_m0.ld")
 
-SET(CFLAGS_COMMON "-Os -g3 -Wall -Wextra ${HACKRF_OPTS} ${COMMON_FLAGS} -fno-common -MD")
+SET(CFLAGS_COMMON "-Os -g3 -Wall -Wextra ${HACKRF_OPTS} -fno-common -MD")
 SET(LDFLAGS_COMMON "-nostartfiles -Wl,--gc-sections")
 
 if(V STREQUAL "1")
@@ -80,7 +80,7 @@ endif()
 SET(CPUFLAGS_M0 "-mthumb -mcpu=cortex-m0 -mfloat-abi=soft")
 SET(CFLAGS_M0 "-std=gnu99 ${CFLAGS_COMMON} ${CPUFLAGS_M0} -DLPC43XX_M0")
 SET(CXXFLAGS_M0 "-std=gnu++0x ${CFLAGS_COMMON} ${CPUFLAGS_M0} -DLPC43XX_M0")
-SET(LDFLAGS_M0 "${LDFLAGS_COMMON} ${CPUFLAGS_M0} ${LDSCRIPT_M0} -Xlinker -Map=m0.map --specs=nano.specs")
+SET(LDFLAGS_M0 "${LDFLAGS_COMMON} ${CPUFLAGS_M0} ${LDSCRIPT_M0} -Xlinker -Map=m0.map")
 
 SET(CPUFLAGS_M4 "-mthumb -mcpu=cortex-m4 -mfloat-abi=hard -mfpu=fpv4-sp-d16")
 SET(CFLAGS_M4 "-std=gnu99 ${CFLAGS_COMMON} ${CPUFLAGS_M4} -DLPC43XX_M4")

firmware/hackrf_usb/CMakeLists.txt

@@ -18,7 +18,7 @@
 # Boston, MA 02110-1301, USA.
 #
 
-cmake_minimum_required(VERSION 2.8.9)
+cmake_minimum_required(VERSION 3.1.3)
 set(CMAKE_TOOLCHAIN_FILE ../toolchain-arm-cortex-m.cmake)
 
 project(hackrf_usb C)

firmware/toolchain-arm-cortex-m.cmake

@@ -22,10 +22,9 @@ set(CMAKE_SYSTEM_NAME Generic)
 set(CMAKE_SYSTEM_VERSION 1)
 set(CMAKE_SYSTEM_PROCESSOR arm)
 
-include(CMakeForceCompiler)
-
-CMAKE_FORCE_C_COMPILER(arm-none-eabi-gcc GNU)
-CMAKE_FORCE_CXX_COMPILER(arm-none-eabi-g++ GNU)
+set(CMAKE_C_COMPILER arm-none-eabi-gcc)
+set(CMAKE_CXX_COMPILER arm-none-eabi-g++)
+set(CMAKE_EXE_LINKER_FLAGS_INIT "--specs=nosys.specs")
 
 execute_process(
   COMMAND ${CMAKE_C_COMPILER} -print-file-name=libc.a