zoul: Add support for flashing to multiple devices

This adds support for flashing to multiple devices, by implementing the
$MOTES option used by the Z1.
This replaces the $PORT interface, as it only allowed flashing to one
device at a time, and the $MOTES interface was still used for other
tasks (such as getting a list of connected devices).

A foreach loop is used to dynamically create an upload rule per device
that needs to be flashed.
The "main" upload rule depends on the device specific ones.
This allows for parallel flashing.

The PORT variable can still be sued for backwards compatibility.

Changed the MOTES variable that makes a $(shell) call to not be
recursively expanded.

platform/zoul/Makefile.zoul

@@ -12,10 +12,6 @@ endif
 PYTHON = python
 BSL_FLAGS += -e -w -v
 
-ifdef PORT
-  BSL_FLAGS += -p $(PORT)
-endif
-
 ### Configure the build for the board and pull in board-specific sources
 CONTIKI_TARGET_DIRS += . dev
 CONTIKI_TARGET_DIRS += . $(BOARD)
@@ -57,28 +53,48 @@ endif
 ### Detect if a mote is connected over serial port
 ifeq ($(HOST_OS),Darwin)
   USBDEVPREFIX=
-  MOTELIST = $(CONTIKI)/tools/zolertia/motelist-zolertia-macos
+  MOTELIST := $(CONTIKI)/tools/zolertia/motelist-zolertia-macos
-  MOTES = $(shell $(MOTELIST) -c 2>&- | cut -f 2 -d ,)
+  MOTES := $(shell $(MOTELIST) -c 2>&- | cut -f 2 -d ,)
-  SERIALDUMP = $(CONTIKI)/tools/sky/serialdump-macos
+  SERIALDUMP := $(CONTIKI)/tools/sky/serialdump-macos
 else
 ### If we are not running under Mac, we assume Linux
   USBDEVPREFIX=
-  SERIALDUMP = $(CONTIKI)/tools/sky/serialdump-linux
+  SERIALDUMP := $(CONTIKI)/tools/sky/serialdump-linux
-  MOTELIST = $(CONTIKI)/tools/zolertia/motelist-zolertia
+  MOTELIST := $(CONTIKI)/tools/zolertia/motelist-zolertia
-  MOTES = $(shell $(MOTELIST) -b $(MOTELIST_ZOLERTIA) -c 2>&- | cut -f 2 -d , | \
+  MOTES := $(shell $(MOTELIST) -b $(MOTELIST_ZOLERTIA) -c 2>&- | cut -f 2 -d , | \
             perl -ne 'print $$1 . " " if(m-(/dev/\w+)-);')
 endif
 
-%.upload: %.bin %.elf
+### If PORT is defined, override to keep backward compatibility
+ifdef PORT
+  MOTES := $(PORT)
+endif
+
+### Check the BSL script exists
 ifeq ($(wildcard $(BSL)), )
+%.upload:
 	@echo "ERROR: Could not find the cc2538-bsl script. Did you run 'git submodule update --init' ?"
 else
-	$(eval BSL_ADDRESS_ARG := -a $(shell $(OBJDUMP) -h $*.elf | grep -B1 LOAD | \
+### Upload to every MOTE
-	                               grep -Ev 'LOAD|\-\-' | awk '{print "0x" $$5}' | \
+%.upload: $(foreach MOTE,$(MOTES),%.$(MOTE))
-	                               sort -g | head -1))
+	@# Dummy recipe to prevent "No rule to make *.upload errors"
-	$(PYTHON) $(BSL) $(BSL_FLAGS) $(BSL_ADDRESS_ARG) $<
 endif
 
+### Variable that expands into a pattern rule to upload to a given MOTE.
+### Requires $(MOTE) to be defined
+### $$$$ Double escapes $s that need to be passed to the shell - once for when make parses UPLOAD_RULE, and once for when the expanded rule is parsed by make.
+define UPLOAD_RULE
+%.$(MOTE): %.bin %.elf
+	@echo "Flashing $(MOTE)"
+	@BSL_ADDRESS=`$(OBJDUMP) -h $$*.elf | grep -B1 LOAD | \
+	             grep -Ev 'LOAD|\-\-' | awk '{print "0x" $$$$5}' | \
+	             sort -g | head -1`; \
+	$(PYTHON) $(BSL) $(BSL_FLAGS) -a $$$${BSL_ADDRESS} -p $(MOTE) $$<
+endef
+
+### Create an upload rule for every MOTE connected
+$(foreach MOTE,$(MOTES),$(eval $(UPLOAD_RULE)))
+
 motelist:
 	$(MOTELIST)
 zoul-motelist:
@@ -86,16 +102,8 @@ zoul-motelist:
 zoul-motes:
 	@echo $(MOTES)
 
-ifdef PORT
-serialview:
-	$(SERIALDUMP) -b115200 $(USBDEVPREFIX) $(PORT) | $(CONTIKI)/tools/timestamp
-
-login:
-	$(SERIALDUMP) -b115200 $(USBDEVPREFIX) $(PORT)
-else
 serialview:
 	$(SERIALDUMP) -b115200 $(USBDEVPREFIX)$(firstword $(MOTES)) | $(CONTIKI)/tools/timestamp
 
 login:
 	$(SERIALDUMP) -b115200 $(USBDEVPREFIX)$(firstword $(MOTES))
-endif