Kconfig: added configurations; fixed Makefiles accordingly

This adds the needed configuration items: architectures, extension,
cross_compile and wrpc_root.  So, what we passed on environment and
command line is now in the configuration file.

This changes the priorities of such options, so the Makefile is
changed to force $(CC), $(LD) and $(CROSS_COMPILE) down to subprojects
(i.e. pp_printf and arch-wrs/mini-rpc).  Also, we need to remove
quotes from .config items, and this is ugly linesin ./Makefile

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

Kconfig

+
+mainmenu "PPSi configuration"
+
+choice
+	prompt "Architecture to build for"
+
+config ARCH_UNIX
+	bool "Unix (Linux and likely other systems)"
+	help
+	  ARCH=unix supports standard Unix system calls, although
+	  the code most likely includes some Linux dependencies.
+	  Choose this architecture if you build for a Linux PC
+	  or embedded system
+
+config ARCH_BARE_I386
+	bool "Bare i386"
+	help
+	  This architecture builds a Linux-i386 executable that
+	  does not rely on the standard C library, but makes
+	  system calls directly.  This architecture is a test case
+	  to ensure the code can run in freestanding environments
+	  (microcontrollers or other contexts with no operating system)
+
+config ARCH_BARE_X86_64
+	bool "Bare x86-64"
+	help
+	  This architecture builds a Linux-x86-64 executable that
+	  does not rely on the standard C library, but makes
+	  system calls directly.  This architecture is a test case
+	  to ensure the code can run in freestanding environments
+	  (microcontrollers or other contexts with no operating system)
+
+config ARCH_WRPC
+	bool "White Rabbit PTP Core (WR Node)"
+	select CONFIG_EXT_WR
+	help
+	  Build PPSi for use in the WRPC environment (SPEC card or similar
+	  one).  This is a freestanding build, without operating system.
+	  The configuration selects the "White Rabbit" protocol extension.
+
+config ARCH_WRS
+	bool "White Rabbit Switch"
+	select CONFIG_EXT_WR
+	help
+	  Build PPSi for use in the WR switch. The computer is a standard
+	  ARM-Linux host with hardware timestamping and internal PLLs
+	  needed to achieve sub-ns synchnonization. 
+	  The configuration selects the "White Rabbit" protocol extension.
+
+endchoice
+
+config ARCH
+       string
+       default "unix" if ARCH_UNIX
+       default "bare-i386" if ARCH_BARE_I386
+       default "bare-x86-64" if ARCH_BARE_X86_64
+       default "wrpc" if ARCH_WRPC
+       default "wrs" if ARCH_WRS
+
+
+
+choice EXTENSION
+	prompt "Protocol Extension"
+
+config EXT_WR
+	bool "White Rabbit" if ARCH_WRS || ARCH_WRPC
+	help
+	  Build WR-PTP (which is able to works as a standard PTP agent,
+	  when the peer is not WR-aware).
+
+config EXT_NONE
+	bool "None"
+	default y
+	help
+	  Select not protocol extension (build standard PTP-V2 daemon).
+
+endchoice
+
+config EXTENSION
+       string
+       default "whiterabbit" if EXT_WR
+       default "" if EXT_NONE
+
+
+
+config CROSS_COMPILE
+       string "Cross compiler prefix"
+       default "/opt/gcc-lm32/bin/lm32-elf-" if ARCH_WRPC
+       default "/opt/arm-wrswitch/bin/arm-linux-" if ARCH_WRS
+       default ""
+
+config ARCH_CFLAGS
+       string
+       default "-m32" if ARCH_BARE_I386
+       default "-m64" if ARCH_BARE_X86_64
+       default ""
+
+config ARCH_LDFLAGS
+       string
+       default "-m elf_i386" if ARCH_BARE_I386
+       default "-m elf_x86_64" if ARCH_BARE_X86_64
+       default ""
+
+config WRPCSW_ROOT
+       string "Source location of wrpc-sw"
+       depends on ARCH_WRPC
+       default "../wrpc-sw"

Makefile

 #
-# Alessandro Rubini for CERN, 2011 -- public domain
+# Alessandro Rubini for CERN, 2011,2013 -- public domain
 #
 
-# The default is not extension. Uncomment here or set on the command line
-# PROTO_EXT ?= whiterabbit
+# We are now Kconfig-based
+-include $(CURDIR)/.config
 
-# The default architecture is hosted GNU/Linux stuff
-ARCH ?= unix
+# We still accept command-line choices like we used to do.
+# Also, we must remove the quotes from these Kconfig values
+PROTO_EXT ?= $(patsubst "%",%,$(CONFIG_EXTENSION))
+ARCH ?= $(patsubst "%",%,$(CONFIG_ARCH))
+CROSS_COMPILE ?= $(patsubst "%",%,$(CONFIG_CROSS_COMPILE))
+WRPCSW_ROOT ?= $(patsubst "%",%,$(CONFIG_WRPCSW_ROOT))
+
+# For "make config" to work, we need a valid ARCH
+ifeq ($(ARCH),)
+   ARCH = unix
+endif
 
 # Also, you can set USER_CFLAGS, like this (or on the command line)
 # USER_CFLAGS = -DVERB_LOG_MSGS
@@ -24,6 +33,11 @@ STRIP           = $(CROSS_COMPILE)strip
 OBJCOPY         = $(CROSS_COMPILE)objcopy
 OBJDUMP         = $(CROSS_COMPILE)objdump
 
+# To cross-build bare stuff (x86-64 under i386 and vice versa). We need this:
+LD := $(LD) $(shell echo $(CONFIG_ARCH_LDFLAGS))
+CC := $(CC) $(shell echo $(CONFIG_ARCH_CFLAGS))
+# (I apologize, but I couldn't find another way to remove quotes)
+
 # Instead of repeating "ppsi" over and over, bless it TARGET
 TARGET = ppsi
 
@@ -50,7 +64,7 @@ ifndef CONFIG_NO_PRINTF
 OBJ-y += pp_printf/pp-printf.o
 
 pp_printf/pp-printf.o: $(wildcard pp_printf/*.[ch])
-	$(MAKE) -C pp_printf pp-printf.o
+	$(MAKE) -C pp_printf pp-printf.o CC="$(CC)" LD="$(LD)"
 endif
 
 # We need this -I so <arch/arch.h> can be found
@@ -58,7 +72,7 @@ CFLAGS += -Iarch-$(ARCH)/include
 
 # proto-standard is always included, as it provides default function
 # so the extension can avoid duplication of code.
-ifdef PROTO_EXT
+ifneq ($(PROTO_EXT),)
   include proto-ext-$(PROTO_EXT)/Makefile
 endif
 include proto-standard/Makefile

arch-wrpc/Makefile

@@ -5,7 +5,7 @@ CFLAGS += -ffreestanding -Os \
 	-Itools
 
 # Root of wrpc-sw project
-WRPCSW_ROOT ?= ..
+WRPCSW_ROOT ?= $(CONFIG_WRPCSW_ROOT)
 
 CFLAGS += -I$(WRPCSW_ROOT)/include -I$(WRPCSW_ROOT)/include/std -I$(WRPCSW_ROOT)/softpll
 

arch-wrs/Makefile

@@ -28,6 +28,7 @@ include time-unix/Makefile
 CFLAGS += -Iproto-ext-whiterabbit
 
 # mini-rpc directory contains minipc library
+export CROSS_COMPILE
 MINIPC_DIR := $A/mini-rpc
 MINIPC_LIB := $(MINIPC_DIR)/libminipc.a
 CFLAGS += -I$(MINIPC_DIR)