merging two folders related to default binary

firmware/config/boards/f407-discovery/board.mk

@@ -1,5 +1,5 @@
 # List of all the board related files.
-BOARDSRC = $(PROJECT_DIR)/config/boards/st_stm32f4/board_extra.c
+BOARDSRC = $(PROJECT_DIR)/config/boards/f407-discovery/board_extra.c
 
 # MCU defines
 DDEFS += -DSTM32F407xx

firmware/config/boards/f407-discovery/readme.md

@@ -0,0 +1,2 @@
+
+This folder is used to generate 'all' version of .ini file and default binaries

firmware/config/boards/st_stm32f4/readme.txt

@@ -1,2 +0,0 @@
-The files here are responsible for GPIO pin configuration on OS startup. rusEfi would later re-configure all the pins for specific
-application so these files only matter for the first half a second of firmware startup.

firmware/rusefi.mk

@@ -16,7 +16,7 @@ $(error Please run 'make' again. Please make sure you have 'git' command in PATH
 endif
 
 ifeq ($(PROJECT_BOARD),)
-  PROJECT_BOARD = st_stm32f4
+  PROJECT_BOARD = f407-discovery
 endif
 
 ifeq ($(PROJECT_CPU),)
@@ -54,7 +54,7 @@ else ifeq ($(PROJECT_CPU),cypress)
 	CPU_HWLAYER = ports/cypress
 else ifeq ($(PROJECT_CPU),simulator)
 else
-$(error Unexpected PROJECT_CPU)
+$(error Unexpected PROJECT_CPU [$(PROJECT_CPU)])
 endif
 
 ifeq ($(CPU_STARTUP_DIR),)