***********************目标***********************************
1.分析uboot1.3.4如何引导内核
2.uboot1.3.4和内核之间的参数传递
3.uboot1.3.4的命令实现
4.uboot1.3.4的环境变量
***********************目标***********************************
^^^^^^^^^^^^^^^^^^^^^^^^从头开始,fighting^^^^^^^^^^^^^^^^^^^^^^^^
***********************顶层Makefile*******************************
点击(此处)折叠或打开
-
VERSION = 1
-
PATCHLEVEL = 3
-
SUBLEVEL = 4
-
EXTRAVERSION =
-
U_BOOT_VERSION = $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION)
-
VERSION_FILE = $(obj)include/version_autogenerated.h
由代码可知uboot的版本为1.3.4。继续往下
-
#########################################################################
-
#
-
# U-boot build supports producing a object files to the separate external
-
# directory. Two use cases are supported:
-
#
-
# 1) Add O= to the make command line
-
# 'make O=/tmp/build all'
-
#
-
# 2) Set environement variable BUILD_DIR to point to the desired location
-
# 'export BUILD_DIR=/tmp/build'
-
# 'make'
-
#
-
# The second approach can also be used with a MAKEALL script
-
# 'export BUILD_DIR=/tmp/build'
-
# './MAKEALL'
-
#
-
# Command line 'O=' setting overrides BUILD_DIR environent variable.
-
#
-
# When none of the above methods is used the local build is performed and
-
# the object files are placed in the source directory.
-
#
以上是关于输出目录的解释,为了保持目录的干净。
***********************顶层Makefile*******************************
################### 终端操作############################
###### 现在编译并生成u-boot.bin,输出目录即是当前源码目录.使用以下命令:
###### 1.make distclean
###### 2.make _config
###### 3.make (all)
################### 终端操作############################
***********************顶层Makefile*******************************
点击(此处)折叠或打开
-
smdkv210single_config : unconfig
-
@$(MKCONFIG) $(@:_config=) arm s5pc11x smdkc110 samsung s5pc110
-
@echo "TEXT_BASE = 0xc3e00000" > $(obj)board/samsung/smdkc110/config.mk
执行三种操作
unconfig是清除上一次的配置结果。操作结果如下:
rm -rf include/config.h include/config.mk board/*/config.tmp include/autoconf.mk
@$(MKCONFIG) $(@:_config=) arm s5pc11x smdkc110 samsung s5pc110 等效于
./mkconfig smdkv210single arm s5pc11x smdkc110 samsung s5pc110
@echo "TEXT_BASE = 0xc3e00000" > $(obj)board/samsung/smdkc110/config.mk
***********************顶层Makefile*******************************
***********************顶层./mkconfig*******************************
点击(此处)折叠或打开
-
# Script to create header files and links to configure
-
# U-Boot for a specific board.
-
#
-
# Parameters: Target Architecture CPU Board [VENDOR] [SOC]
-
#
-
# (C) 2002-2006 DENX Software Engineering, Wolfgang Denk <wd@denx.de>
-
#
在mkconfig脚本中给出了mkconfig的用法:
#
Parameters: Target Architecture CPU Board
[VENDOR] [SOC]
因此传递给mkconfig的参数的意义分别是: ./mkconfig smdkv210single arm s5pc11x smdkc110 samsung s5pc110
smdkv210single :Target(目标板型号)
arm:Architecture (目标板的CPU架构)
s5pc11x:CPU (具体使用的CPU型号)
smdkc110 :Board
samsung:VENDOR(生产厂家名)
s5pc110:SOC
结果创建链接文件和在include下创建config.h("#include smdkv210single.h>" >>config.h)和config.mk。
***********************顶层./mkconfig*******************************
***********************顶层Makefile*******************************
以上执行完uboot的配置过程,现在开始make。依据从顶层Makefile开始
点击(此处)折叠或打开
-
ifeq ($(obj)include/config.mk,$(wildcard $(obj)include/config.mk)) ############判断是否执行过make _config############
-
-
# load ARCH, BOARD, and CPU configuration ############加载config.mk的配置信息,确定架构、目标板、cPU等配置############
-
include $(obj)include/config.mk
-
export ARCH CPU BOARD VENDOR SOC ############ ARCH CPU BOARD VENDOR SOC =
arm s5pc11x smdkc110 samsung s5pc110 ############
-
-
ifndef CROSS_COMPILE ####决定编译工具链######
-
........
-
ifeq ($(ARCH),arm)####指定工具链的位置######
-
#CROSS_COMPILE = arm-linux-
-
#CROSS_COMPILE = /usr/local/arm/4.4.1-eabi-cortex-a8/usr/bin/arm-linux-
-
#CROSS_COMPILE = /usr/local/arm/4.2.2-eabi/usr/bin/arm-linux-
-
CROSS_COMPILE = /usr/local/arm/arm-2009q3/bin/arm-none-linux-gnueabi-
-
endif
-
# load other configuration############加载其他配置############
include $(TOPDIR)/config.mk
-
................
-
else # !config.mk ############未行过make _config,退出make过程############
-
.....................
-
@echo
"System not configured - see README" >&2
-
endif
加载完各个配置信息后,会生成各个库文件,然后开始真正的编译过程。
$(obj)u-boot.bin: $(obj)u-boot
$(OBJCOPY) ${OBJCFLAGS} -O
binary $< $@
=arm-linux-objcopy -O binary
u-boot u-boot.bin
具体的编译过程,后续。。。。。。
***********************顶层Makefile*******************************
***********************include $(TOPDIR)/config.mk加载其他配置分析*******************************
点击(此处)折叠或打开
-
#
-
# (C) Copyright 2000-2006
-
# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
-
#
-
# See file CREDITS for list of people who contributed to this
-
# project.
-
#
-
# This program is free software; you can redistribute it and/or
-
# modify it under the terms of the GNU General Public License as
-
# published by the Free Software Foundation; either version 2 of
-
# the License, or (at your option) any later version.
-
#
-
# This program is distributed in the hope that it will be useful,
-
# but WITHOUT ANY WARRANTY; without even the implied warranty of
-
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-
# GNU General Public License for more details.
-
#
-
# You should have received a copy of the GNU General Public License
-
# along with this program; if not, write to the Free Software
-
# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
-
# MA 02111-1307 USA
-
#
-
-
#########################################################################
-
-
ifneq ($(OBJTREE),$(SRCTREE))
-
ifeq ($(CURDIR),$(SRCTREE))
-
dir :=
-
else
-
dir := $(subst $(SRCTREE)/,,$(CURDIR))
-
endif
-
-
obj := $(if $(dir),$(OBJTREE)/$(dir)/,$(OBJTREE)/)
-
src := $(if $(dir),$(SRCTREE)/$(dir)/,$(SRCTREE)/)
-
-
$(shell mkdir -p $(obj))
-
else
-
obj :=
-
src :=
-
endif
-
-
# clean the slate ...
-
PLATFORM_RELFLAGS =
-
PLATFORM_CPPFLAGS =
-
PLATFORM_LDFLAGS =
-
-
#
-
# When cross-compiling on NetBSD, we have to define __PPC__ or else we
-
# will pick up a va_list declaration that is incompatible with the
-
# actual argument lists emitted by the compiler.
-
#
-
# [Tested on NetBSD/i386 1.5 + cross-powerpc-netbsd-1.3]
-
-
ifeq ($(ARCH),ppc)
-
ifeq ($(CROSS_COMPILE),powerpc-netbsd-)
-
PLATFORM_CPPFLAGS+= -D__PPC__
-
endif
-
ifeq ($(CROSS_COMPILE),powerpc-openbsd-)
-
PLATFORM_CPPFLAGS+= -D__PPC__
-
endif
-
endif
-
-
ifeq ($(ARCH),arm)
-
ifeq ($(CROSS_COMPILE),powerpc-netbsd-)
-
PLATFORM_CPPFLAGS+= -D__ARM__
-
endif
-
ifeq ($(CROSS_COMPILE),powerpc-openbsd-)
-
PLATFORM_CPPFLAGS+= -D__ARM__
-
endif
-
endif
-
-
#########################################################################
-
-
CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
-
else if [ -x /bin/bash ]; then echo /bin/bash; \
-
else echo sh; fi ; fi)
-
-
ifeq ($(HOSTOS)-$(HOSTARCH),darwin-ppc)
-
HOSTCC = cc
-
else
-
HOSTCC = gcc
-
endif
-
HOSTCFLAGS = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
-
HOSTSTRIP = strip
-
-
#########################################################################
-
#
-
# Option checker (courtesy linux kernel) to ensure
-
# only supported compiler options are used
-
#
-
cc-option = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
-
> /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
-
-
#
-
# Include the make variables (CC, etc...)
-
#
-
AS = $(CROSS_COMPILE)as
-
LD = $(CROSS_COMPILE)ld
-
CC = $(CROSS_COMPILE)gcc
-
CPP = $(CC) -E
-
AR = $(CROSS_COMPILE)ar
-
NM = $(CROSS_COMPILE)nm
-
LDR = $(CROSS_COMPILE)ldr
-
STRIP = $(CROSS_COMPILE)strip
-
OBJCOPY = $(CROSS_COMPILE)objcopy
-
OBJDUMP = $(CROSS_COMPILE)objdump
-
RANLIB = $(CROSS_COMPILE)RANLIB
-
-
#########################################################################
-
-
# Load generated board configuration
-
sinclude $(OBJTREE)/include/autoconf.mk #####和目标板的宏定义相关#########
-
-
ifdef ARCH
-
sinclude $(TOPDIR)/$(ARCH)_config.mk # include architecture dependend rules
-
endif
-
ifdef CPU
-
sinclude $(TOPDIR)/cpu/$(CPU)/config.mk # include CPU specific rules
-
endif
-
ifdef SOC
-
sinclude $(TOPDIR)/cpu/$(CPU)/$(SOC)/config.mk # include SoC specific rules
-
endif
-
ifdef VENDOR
-
BOARDDIR = $(VENDOR)/$(BOARD)
-
else
-
BOARDDIR = $(BOARD)
-
endif
-
ifdef BOARD
-
sinclude $(TOPDIR)/board/$(BOARDDIR)/config.mk # include board specific rules
-
endif
-
-
#########################################################################
-
-
ifneq (,$(findstring s,$(MAKEFLAGS)))
-
ARFLAGS = cr
-
else
-
ARFLAGS = crv
-
endif
-
RELFLAGS= $(PLATFORM_RELFLAGS)
-
DBGFLAGS= -g # -DDEBUG
-
OPTFLAGS= -Os #-fomit-frame-pointer
-
ifndef LDSCRIPT #####在上层Makefile并没有全局定义LDSCRIPT####
-
#LDSCRIPT := $(TOPDIR)/board/$(BOARDDIR)/u-boot.lds.debug
-
ifeq ($(CONFIG_NAND_U_BOOT),y)
-
LDSCRIPT := $(TOPDIR)/board/$(BOARDDIR)/u-boot-nand.lds
-
else
-
LDSCRIPT := $(TOPDIR)/board/$(BOARDDIR)/u-boot.lds
-
#####LDSCRIPT被定义为board/samsung/smdkc110/u-boot.lds####
-
endif
-
endif
-
OBJCFLAGS += --gap-fill=0xff
-
-
gccincdir := $(shell $(CC) -print-file-name=include)
-
-
CPPFLAGS := $(DBGFLAGS) $(OPTFLAGS) $(RELFLAGS) \
-
-D__KERNEL__
-
ifneq ($(TEXT_BASE),)
-
CPPFLAGS += -DTEXT_BASE=$(TEXT_BASE)
-
endif
-
-
ifneq ($(OBJTREE),$(SRCTREE))
-
CPPFLAGS += -I$(OBJTREE)/include2 -I$(OBJTREE)/include
-
endif
-
-
CPPFLAGS += -I$(TOPDIR)/include
-
CPPFLAGS += -fno-builtin -ffreestanding -nostdinc \
-
-isystem $(gccincdir) -pipe $(PLATFORM_CPPFLAGS)
-
-
ifdef BUILD_TAG
-
CFLAGS := $(CPPFLAGS) -Wall -Wstrict-prototypes \
-
-DBUILD_TAG='"$(BUILD_TAG)"'
-
else
-
CFLAGS := $(CPPFLAGS) -Wall -Wstrict-prototypes
-
endif
-
-
CFLAGS += $(call cc-option,-fno-stack-protector)
-
-
# avoid trigraph warnings while parsing pci.h (produced by NIOS gcc-2.9)
-
# this option have to be placed behind -Wall -- that's why it is here
-
ifeq ($(ARCH),nios)
-
ifeq ($(findstring 2.9,$(shell $(CC) --version)),2.9)
-
CFLAGS := $(CPPFLAGS) -Wall -Wno-trigraphs
-
endif
-
endif
-
-
# $(CPPFLAGS) sets -g, which causes gcc to pass a suitable -g
-
# option to the assembler.
-
AFLAGS_DEBUG :=
-
-
# turn jbsr into jsr for m68k
-
ifeq ($(ARCH),m68k)
-
ifeq ($(findstring 3.4,$(shell $(CC) --version)),3.4)
-
AFLAGS_DEBUG := -Wa,-gstabs,-S
-
endif
-
endif
-
-
AFLAGS := $(AFLAGS_DEBUG) -D__ASSEMBLY__ $(CPPFLAGS)
-
-
LDFLAGS += -Bstatic -T $(LDSCRIPT) $(PLATFORM_LDFLAGS)
-
ifneq ($(TEXT_BASE),)
-
LDFLAGS += -Ttext $(TEXT_BASE)
-
endif
-
-
# Location of a usable BFD library, where we define "usable" as
-
# "built for ${HOST}, supports ${TARGET}". Sensible values are
-
# - When cross-compiling: the root of the cross-environment
-
# - Linux/ppc (native): /usr
-
# - NetBSD/ppc (native): you lose ... (must extract these from the
-
# binutils build directory, plus the native and U-Boot include
-
# files don't like each other)
-
#
-
# So far, this is used only by tools/gdb/Makefile.
-
-
ifeq ($(HOSTOS)-$(HOSTARCH),darwin-ppc)
-
BFD_ROOT_DIR = /usr/local/tools
-
else
-
ifeq ($(HOSTARCH),$(ARCH))
-
# native
-
BFD_ROOT_DIR = /usr
-
else
-
#BFD_ROOT_DIR = /LinuxPPC/CDK # Linux/i386
-
#BFD_ROOT_DIR = /usr/pkg/cross # NetBSD/i386
-
BFD_ROOT_DIR = /opt/powerpc
-
endif
-
endif
-
-
ifeq ($(PCI_CLOCK),PCI_66M)
-
CFLAGS := $(CFLAGS) -DPCI_66M
-
endif
-
-
#########################################################################
-
-
export CONFIG_SHELL HPATH HOSTCC HOSTCFLAGS CROSS_COMPILE \
-
AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP \
-
MAKE
-
export TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS CPPFLAGS CFLAGS AFLAGS
-
-
#########################################################################
-
-
ifndef REMOTE_BUILD
-
-
%.s: %.S
-
$(CPP) $(AFLAGS) -o $@ $<
-
%.o: %.S
-
$(CC) $(AFLAGS) -c -o $@ $<
-
%.o: %.c
-
$(CC) $(CFLAGS) -c -o $@ $<
-
-
else
-
-
$(obj)%.s: %.S
-
$(CPP) $(AFLAGS) -o $@ $<
-
$(obj)%.o: %.S
-
$(CC) $(AFLAGS) -c -o $@ $<
-
$(obj)%.o: %.c
-
$(CC) $(CFLAGS) -c -o $@ $<
-
endif
-
-
#########################################################################
从board/samsung/smdkc110/u-boot.lds可知
-
.text :
-
{
-
cpu/s5pc11x/start.o (.text)
-
cpu/s5pc11x/s5pc110/cpu_init.o (.text)
-
board/samsung/smdkc110/lowlevel_init.o (.text)
-
cpu/s5pc11x/onenand_cp.o (.text)
-
cpu/s5pc11x/nand_cp.o (.text)
-
cpu/s5pc11x/movi.o (.text)
-
common/secure_boot.o (.text)
-
common/ace_sha1.o (.text)
-
cpu/s5pc11x/pmic.o (.text)
-
*(.text)
-
}
生成的bin文件从cpu/s5pc11x/start.o开始执行。
***********************include $(TOPDIR)/config.mk加载其他配置分析*******************************
***********************Makefile总结*******************************
顶层Makefile包含了各个子Makefile,并且用export定义了全局变量。当make时,Makefile顺序往下拓展执行,各个子Makefile被include进来,依据全局变量的定义,决定是否包含其他文件
***********************Makefile总结*******************************
阅读(991) | 评论(0) | 转发(0) |