Kbuild: Build minimal libc as a static library.

This commit changes the way libc is built.
Instead of building a hierarchy of objects linked into the
microkernel, libc minimal is built as a static library and
linked against the microkernel binary.
The location of the libc is configurable with the variable
KLIBC_DIR. This gives the flexibility to build against a
different libc other than minimal.

Change-Id: I9c0b6a684a9f3b407861aa387727c45eceb269c4
Signed-off-by: Juan Manuel Cruz <juan.m.cruz.alcaraz@linux.intel.com>

Makefile

@@ -7,7 +7,7 @@ PATCHLEVEL 	   = 0
 SUBLEVEL	   = 0
 NAME 		   = Tiny Mountain
 
-export SOURCE_DIR PROJECT VPFILE
+export SOURCE_DIR PROJECT VPFILE KLIBC_DIR
 
 # *DOCUMENTATION*
 # To see a list of typical targets execute "make help"
@@ -575,8 +575,10 @@ scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \
 	$(Q)$(MAKE) $(build)=$(@)
 
 # Objects we will link into tinymountain / subdirs we need to visit
-core-y := arch/ kernel/ misc/ lib/ net/
+KLIBC_DIR := lib/libc/minimal
+core-y := arch/ kernel/ misc/ net/
 bsp-y  := drivers/
+libs-y := $(KLIBC_DIR)/
 
 ifneq ($(strip $(PROJECT)),)
 core-y += $(SOURCE_DIR)

lib/Makefile

@@ -1 +0,0 @@
-obj-y = libc/

lib/libc/Makefile

@@ -1,5 +0,0 @@
-#FIXME 	This Makefile is skipping one level of recursivity
-#	to avoid modifyng the file source/Makefile that
-#	is needed by the current build system.
-
-obj-y = minimal/source/

lib/libc/minimal/Makefile

@@ -1,60 +1,5 @@
-# Makefile - Makefile to build minimal stdlib
-
-#
-# Copyright (c) 2014 Wind River Systems, Inc.
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are met:
-#
-# 1) Redistributions of source code must retain the above copyright notice,
-# this list of conditions and the following disclaimer.
-#
-# 2) Redistributions in binary form must reproduce the above copyright notice,
-# this list of conditions and the following disclaimer in the documentation
-# and/or other materials provided with the distribution.
-#
-# 3) Neither the name of Wind River Systems nor the names of its contributors
-# may be used to endorse or promote products derived from this software without
-# specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
-# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-# POSSIBILITY OF SUCH DAMAGE.
-#
-
-include $(subst \,/,${VXMICRO_BASE})/make/env/defs.base
-
-LIB_NAME = minimal
-STDLIB = ${LIB_NAME}
-
-vSTDLIB_HDR_PATH = ${vBASE}/lib/libc/${STDLIB}/include
-${LIB_NAME}_INCLUDE_DIR = ${vSTDLIB_HDR_PATH}
-
-${LIB_NAME}_KERNEL = string stdout
-
-${LIB_NAME}_SRC = $(foreach lib,${${LIB_NAME}_${STDLIB_TYPE}},$(wildcard source/${lib}/*.c))
-
-${LIB_NAME}_CFLAGS += ${iSECTION_GC_CFLAGS}
-
-.PHONY: aliases
-.DEFAULT_GOAL = aliases
-
-include ${vMAKE}/target/make.library
-
-ALIAS_DIR ?= ${vOUT_DIR}
-
-aliases: ${ALIAS_DIR}/libc.a ${ALIAS_DIR}/libm.a
-
-${ALIAS_DIR}/libm.a: ${ALIAS_DIR}/libc.a
-	$q${HOS_CopyFile} $< $@
-
-${ALIAS_DIR}/libc.a: ${vOUT_DIR}/lib${LIB_NAME}.a
-	$q${HOS_CopyFile} $< $@
+lib-y := source/stdout/fprintf.o
+lib-y += source/stdout/prf.o
+lib-y += source/stdout/sprintf.o
+lib-y += source/stdout/stdout_console.o
+lib-y += source/string/string.o

lib/libc/minimal/source/Makefile

@@ -1,2 +0,0 @@
-obj-y = stdout/
-obj-y += string/

lib/libc/minimal/source/stdout/Makefile

@@ -1,4 +0,0 @@
-obj-y = fprintf.o
-obj-y += prf.o
-obj-y += sprintf.o
-obj-y += stdout_console.o

lib/libc/minimal/source/string/Makefile

@@ -1 +0,0 @@
-obj-y = string.o

scripts/link-tinymountain.sh

@@ -70,6 +70,7 @@ linker_command()
 initial_link()
 {
 	${CC} -o ${1} @${2}  -T ${3}
+	cp ${KLIBC_DIR}/lib.a ${KLIBC_DIR}/libc.a
 }
 
 #Generates IDT and merge them into final binary