makefiles: fix build under cygwin/msys2 on windows

This forces SHELL to be cmd.exe under these platforms.

Signed-off-by: Sean Cross <sean@xobs.io>

riscv-blink/Makefile

@@ -16,9 +16,17 @@ COPY       := cp -a
 PATH_SEP   := /
 
 ifeq ($(OS),Windows_NT)
-COPY       := copy
+# When SHELL=sh.exe and this actually exists, make will silently
-RM         := del
+# switch to using that instead of cmd.exe.  Unfortunately, there's
-PATH_SEP   := \\
+# no way to tell which environment we're running under without either
+# (1) printing out an error message, or (2) finding something that
+# works everywhere.
+# As a result, we force the shell to be cmd.exe, so it works both
+# under cygwin and normal Windows.
+SHELL      = cmd.exe
+COPY       = copy
+RM         = del
+PATH_SEP   = \\
 endif
 
 BASE_DIR   := .

riscv-usb-cdcacm/Makefile

@@ -16,9 +16,17 @@ COPY       := cp -a
 PATH_SEP   := /
 
 ifeq ($(OS),Windows_NT)
-COPY       := copy
+# When SHELL=sh.exe and this actually exists, make will silently
-RM         := del
+# switch to using that instead of cmd.exe.  Unfortunately, there's
-PATH_SEP   := \\
+# no way to tell which environment we're running under without either
+# (1) printing out an error message, or (2) finding something that
+# works everywhere.
+# As a result, we force the shell to be cmd.exe, so it works both
+# under cygwin and normal Windows.
+SHELL      = cmd.exe
+COPY       = copy
+RM         = del
+PATH_SEP   = \\
 endif
 
 BASE_DIR   := .
@@ -63,7 +71,7 @@ ALL        := all
 TARGET     := $(PACKAGE).elf
 CLEAN      := clean
 
-$(ALL): $(TARGET) $(PACKAGE).bin $(PACKAGE).ihex
+$(ALL): $(TARGET) $(PACKAGE).bin $(PACKAGE).ihex $(PACKAGE).dfu
 
 $(OBJECTS): | $(OBJ_DIR)
 

verilog-blink/Makefile

@@ -16,18 +16,18 @@ RM         = rm -rf
 COPY       = cp -a
 PATH_SEP   = /
 ifeq ($(OS),Windows_NT)
-# When SHELL=sh.exe and this actually exists, we're able to run
+# When SHELL=sh.exe and this actually exists, make will silently
-# the `which` command.  Under these circumstances, the cmd.exe
+# switch to using that instead of cmd.exe.  Unfortunately, there's
-# equivalents "copy" and "del" don't work.  Additionally, the
+# no way to tell which environment we're running under without either
-# path separator can mess things up.
+# (1) printing out an error message, or (2) finding something that
-# Therefore, if we're running under Windows but have a valid `sh.exe`,
+# works everywhere.
-# don't use the Windows equivalents.
+# As a result, we force the shell to be cmd.exe, so it works both
-ifneq (, $(shell which $(SHELL)))
+# under cygwin and normal Windows.
+SHELL      = cmd.exe
 COPY       = copy
 RM         = del
 PATH_SEP   = \\
 endif
-endif
 
 ifeq ($(FOMU_REV),evt3)
 PCF       ?= $(PCF_PATH)/fomu-evt3.pcf