u-boot的配置过程分析
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2022-06-04 08:51:16
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前面在分析主makefile的时候，我们知道执行make 100ask24x0_config这个命令会在include目录下创建一个config.mk文件。
那么为什么编译就会生成这个文件呢？我们来看下这个命令究竟做了什么，在主Makefile中我们可以找到以下命令：
100ask24x0_config : unconfig
@$(MKCONFIG) $(@:_config=) arm arm920t 100ask24x0 NULL s3c24x0首先我们看这个命令的依赖：unconfig
unconfig:
@rm -f $(obj)include/config.h $(obj)include/config.mk \
$(obj)board/*/config.tmp $(obj)board/*/*/config.tmp其实就是删除之前配置好的文件。
1. $(@:_config=)
[email protected]表示 规则的目标文件名，@在$()中与[email protected]一样，表示规则中的目标文件。同时在makefile中，$(var:a=b)表示 变量值的替换。
把变量"var"( 即$(var) )中的所有以"a"字串"结尾"的"a"替换成"b"字串。
100ask24x0_config里的_config部分用空替换，得到：100ask24x0，这就是第一个参数
$1: 100ask24x0
$2: arm
$3: arm920t
$4: 100ask24x0
$5: NULL
$6: s3c24x0
所以，$# = 6
[email protected]$(MKCONFIG)
@表示静默编译，MKCONFIG是一个全局变量，其实就代表根目录下的mkconfig
MKCONFIG := $(SRCTREE)/mkconfig
export MKCONFIG所以在我们执行 make 100ask24x0_config命令的时候，其实就是运行这个脚本文件，并传输给这个脚本6个参数。
3.mkconfig脚本文件分析
1.设定BOARD_NAME
APPEND=no # Default: Create new config file
BOARD_NAME="" # Name to print in make output
while [ $# -gt 0 ] ; do
case "$1" in
--) shift ; break ;;
-a) shift ; APPEND=yes ;;
-n) shift ; BOARD_NAME="${1%%_config}" ; shift ;;
*) break ;;
esac
done
[ "${BOARD_NAME}" ] || BOARD_NAME="$1"$#是传进来参数的总的个数 是6，大于零，执行case语句
$1 = 100ask24x0，能匹配的是*（万能匹配），然后BREAK，直接跳出WHILE循环
BOARD_NAME是空，所以中括号里面是FAULSE，所以要继续执行BOARD_NAME="$1"
所以以上代码执行的效果就是BOARD_NAME = 100ask24x0
2.判断传输的参数，打印提示
[ $# -lt 4 ] && exit 1
[ $# -gt 6 ] && exit 1
echo "Configuring for ${BOARD_NAME} board..."如果$#小于4，则exit 1（mkconfig脚本返回1），如果$#大于6，则也返回1.
3.创建符号链接
#
# Create link to architecture specific headers
#
if [ "$SRCTREE" != "$OBJTREE" ] ; then
mkdir -p ${OBJTREE}/include
mkdir -p ${OBJTREE}/include2
cd ${OBJTREE}/include2
rm -f asm
ln -s ${SRCTREE}/include/asm-$2 asm
LNPREFIX="../../include2/asm/"
cd ../include
rm -rf asm-$2
rm -f asm
mkdir asm-$2
ln -s asm-$2 asm
else
cd ./include
rm -f asm
ln -s asm-$2 asm
fi
rm -f asm-$2/arch
if [ -z "$6" -o "$6" = "NULL" ] ; then
ln -s ${LNPREFIX}arch-$3 asm-$2/arch
else
ln -s ${LNPREFIX}arch-$6 asm-$2/arch
fi
if [ "$2" = "arm" ] ; then
rm -f asm-$2/proc
ln -s ${LNPREFIX}proc-armv asm-$2/proc
fi第一个：在include目录下创建asm文件，指向asm-arm。
cd ./include
rm -f asm
ln -s asm-$2 asm
注意:这个地方已经进入./include文件夹下，所以后面的操作都是在这个文件夹下
第二个：在inlcude/asm-arm下创建一个arch文件，指向include/asm-arm/arch-s3c24x0
if [ -z "$6" -o "$6" = "NULL" ] ; then
ln -s ${LNPREFIX}arch-$3 asm-$2/arch
else
ln -s ${LNPREFIX}arch-$6 asm-$2/arch
fi
第六个参数为空或者位NULL， 执行ln -s ${LNPREFIX}arch-$3 asm-$2/arch，否则执行 ln -s ${LNPREFIX}arch-$6 asm-$2/arch
4.创建并追加include/config文件
#
# Create include file for Make
#
echo "ARCH = $2" > config.mk
echo "CPU = $3" >> config.mk
echo "BOARD = $4" >> config.mk
[ "$5" ] && [ "$5" != "NULL" ] && echo "VENDOR = $5" >> config.mk
[ "$6" ] && [ "$6" != "NULL" ] && echo "SOC = $6" >> config.mk执行完之后的文件内容如下：
5.创建头文件
#
# Create board specific header file
#
if [ "$APPEND" = "yes" ] # Append to existing config file
then
echo >> config.h
else
> config.h # Create new config file
fi
echo "/* Automatically generated - do not edit */" >>config.h
echo "#include <configs/$1.h>" >>config.h创建一个config.h，并且追加内容：
/* Automatically generated - do not edit */
#include <configs/$1.h>
追加完成之后：
附：脚本文件的源代码
所以，100ask24x0.h这个头文件是十分重要的，关乎整个工程的配置。
头文件的所有内容如下：
/*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <[email protected]>
* Gary Jennejohn <[email protected]>
* David Mueller <[email protected]>
*
* Configuation settings for the SAMSUNG SMDK2410 board.
*
* 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
*/
#ifndef __CONFIG_H
#define __CONFIG_H
/*
* High Level Configuration Options
* (easy to change)
*/
#define CONFIG_ARM920T 1 /* This is an ARM920T Core */
#define CONFIG_S3C2410 1 /* in a SAMSUNG S3C2410 SoC */
#define CONFIG_SMDK2410 1 /* on a SAMSUNG SMDK2410 Board */
/* input clock of PLL */
#define CONFIG_SYS_CLK_FREQ 12000000 /* the SMDK2410 has 12MHz input clock */
//#define CONFIG_SYS_CLK_FREQ 16934400 /* the SMDK2410 has 12MHz input clock */
#define USE_920T_MMU 1
#define CONFIG_USB_DEVICE 1
#ifdef CONFIG_USB_DEVICE
#define CONFIG_USE_IRQ 1
#endif
#define CONFIG_JFFS2_CMDLINE 1
#define CONFIG_JFFS2_NAND 1
#define MTDIDS_DEFAULT "nand0=nandflash0"
#define MTDPARTS_DEFAULT "mtdparts=nandflash0:[email protected](bootloader)," \
"128k(params)," \
"2m(kernel)," \
"-(root)"
/*
* Size of malloc() pool
*/
#define CFG_MALLOC_LEN (CFG_ENV_SIZE + 128*1024)
#define CFG_GBL_DATA_SIZE 128 /* size in bytes reserved for initial data */
/*
* Hardware drivers
*/
#if 1
#if 0
#define CONFIG_DRIVER_CS8900 1 /* we have a CS8900 on-board */
#define CS8900_BASE 0x19000300
#define CS8900_BUS16 1 /* the Linux driver does accesses as shorts */
#endif
#if !defined(CONFIG_DRIVER_CS8900)
#define CONFIG_DRIVER_DM9000 1
#define CONFIG_DM9000_USE_16BIT 1
#define CONFIG_DM9000_BASE 0x20000000
#define DM9000_IO 0x20000000
#define DM9000_DATA 0x20000004
#endif
#endif
/*
* select serial console configuration
*/
#define CONFIG_SERIAL1 1 /* we use SERIAL 1 on SMDK2410 */
/************************************************************
* RTC
************************************************************/
#define CONFIG_RTC_S3C24X0 1
/* allow to overwrite serial and ethaddr */
#define CONFIG_ENV_OVERWRITE
#define CONFIG_BAUDRATE 115200
/* for tag(s) to transfer message to kernel, www.100ask.net */
#define CONFIG_SETUP_MEMORY_TAGS 1
#define CONFIG_CMDLINE_TAG 1
/***********************************************************
* Command definition
***********************************************************/
#define CONFIG_COMMANDS \
((CONFIG_CMD_DFL | \
CFG_CMD_CACHE | \
/* Start: by www.100ask.net */ \
CFG_CMD_PING | \
CFG_CMD_JFFS2 | \
CFG_CMD_NAND | \
/* End: by www.100ask.net */ \
/*CFG_CMD_EEPROM |*/ \
/*CFG_CMD_I2C |*/ \
/*CFG_CMD_USB |*/ \
CFG_CMD_REGINFO | \
CFG_CMD_DATE | \
CFG_CMD_ELF))
/* this must be included AFTER the definition of CONFIG_COMMANDS (if any) */
#include <cmd_confdefs.h>
#define CONFIG_BOOTDELAY 2
#define CONFIG_BOOTARGS "noinitrd root=/dev/mtdblock3 init=/linuxrc console=ttySAC0"
#define CONFIG_ETHADDR 08:00:3e:26:0a:5b
#define CONFIG_NETMASK 255.255.255.0
#define CONFIG_IPADDR 192.168.7.17
#define CONFIG_SERVERIP 192.168.7.11
/*#define CONFIG_BOOTFILE "elinos-lart" */
#define CONFIG_BOOTCOMMAND "nand read.jffs2 0x30007FC0 kernel; bootm 0x30007FC0"
#if (CONFIG_COMMANDS & CFG_CMD_KGDB)
#define CONFIG_KGDB_BAUDRATE 115200 /* speed to run kgdb serial port */
/* what's this ? it's not used anywhere */
#define CONFIG_KGDB_SER_INDEX 1 /* which serial port to use */
#endif
/*
* Miscellaneous configurable options
*/
#define CFG_LONGHELP /* undef to save memory */
#define CFG_PROMPT "OpenJTAG> " /* Monitor Command Prompt */
#define CFG_CBSIZE 256 /* Console I/O Buffer Size */
#define CFG_PBSIZE (CFG_CBSIZE+sizeof(CFG_PROMPT)+16) /* Print Buffer Size */
#define CFG_MAXARGS 16 /* max number of command args */
#define CFG_BARGSIZE CFG_CBSIZE /* Boot Argument Buffer Size */
#define CFG_MEMTEST_START 0x30000000 /* memtest works on */
#define CFG_MEMTEST_END 0x33F00000 /* 63 MB in DRAM */
#undef CFG_CLKS_IN_HZ /* everything, incl board info, in Hz */
#define CFG_LOAD_ADDR 0x33000000 /* default load address */
/* the PWM TImer 4 uses a counter of 15625 for 10 ms, so we need */
/* it to wrap 100 times (total 1562500) to get 1 sec. */
#define CFG_HZ 1562500
/* valid baudrates */
#define CFG_BAUDRATE_TABLE { 9600, 19200, 38400, 57600, 115200 }
/*-----------------------------------------------------------------------
* Stack sizes
*
* The stack sizes are set up in start.S using the settings below
*/
#define CONFIG_STACKSIZE (128*1024) /* regular stack */
#ifdef CONFIG_USE_IRQ
#define CONFIG_STACKSIZE_IRQ (4*1024) /* IRQ stack */
#define CONFIG_STACKSIZE_FIQ (4*1024) /* FIQ stack */
#endif
/*-----------------------------------------------------------------------
* Physical Memory Map
*/
#define CONFIG_NR_DRAM_BANKS 1 /* we have 1 bank of DRAM */
#define PHYS_SDRAM_1 0x30000000 /* SDRAM Bank #1 */
#define PHYS_SDRAM_1_SIZE 0x04000000 /* 64 MB */
#define PHYS_FLASH_1 0x00000000 /* Flash Bank #1 */
#define CFG_FLASH_BASE PHYS_FLASH_1
#define CFG_MONITOR_BASE PHYS_FLASH_1
/*-----------------------------------------------------------------------
* FLASH and environment organization
*/
#if 0
#define CONFIG_AMD_LV400 1 /* uncomment this if you have a LV400 flash */
#endif
//#define CONFIG_AMD_LV800 1 /* uncomment this if you have a LV800 flash */
#define CFG_MAX_FLASH_BANKS 1 /* max number of memory banks */
#ifdef CONFIG_AMD_LV800
#define PHYS_FLASH_SIZE 0x00100000 /* 1MB */
#define CFG_MAX_FLASH_SECT (19) /* max number of sectors on one chip */
#define CFG_ENV_ADDR (CFG_FLASH_BASE + 0x0F0000) /* addr of environment */
#endif
#ifdef CONFIG_AMD_LV400
#define PHYS_FLASH_SIZE 0x00080000 /* 512KB */
#define CFG_MAX_FLASH_SECT (11) /* max number of sectors on one chip */
#define CFG_ENV_ADDR (CFG_FLASH_BASE + 0x070000) /* addr of environment */
#endif
#define CFG_FLASH_CFI 1
#define CFG_FLASH_CFI_DRIVER 1
#define CFG_FLASH_USE_BUFFER_WRITE 1
#define CONFIG_FLASH_CFI_LEGACY 1
#ifdef CFG_FLASH_CFI_DRIVER
#define CFG_MAX_FLASH_SECT 512 /* max number of sectors on one chip */
#define CFG_FLASH_CFI_WIDTH 0x02 /* FLASH_CFI_16BIT */
#endif
/* timeout values are in ticks */
#define CFG_FLASH_ERASE_TOUT (5*CFG_HZ) /* Timeout for Flash Erase */
#define CFG_FLASH_WRITE_TOUT (5*CFG_HZ) /* Timeout for Flash Write */
//#define CFG_ENV_IS_IN_FLASH 1
#define CFG_ENV_IS_IN_NAND 1
#define CFG_ENV_OFFSET 0x40000
#define CFG_ENV_SIZE 0x20000 /* Total Size of Environment Sector */
/*-----------------------------------------------------------------------
* NAND flash settings
*/
#define CFG_NAND_BASE 0
#define CFG_MAX_NAND_DEVICE 1
#define NAND_MAX_CHIPS 1
#endif /* __CONFIG_H */
附： mkconfig脚本文件
#!/bin/sh -e
# 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 <[email protected]>
#
APPEND=no # Default: Create new config file
BOARD_NAME="" # Name to print in make output
while [ $# -gt 0 ] ; do
case "$1" in
--) shift ; break ;;
-a) shift ; APPEND=yes ;;
-n) shift ; BOARD_NAME="${1%%_config}" ; shift ;;
*) break ;;
esac
done
[ "${BOARD_NAME}" ] || BOARD_NAME="$1"
[ $# -lt 4 ] && exit 1
[ $# -gt 6 ] && exit 1
echo "Configuring for ${BOARD_NAME} board..."
#
# Create link to architecture specific headers
#
if [ "$SRCTREE" != "$OBJTREE" ] ; then
mkdir -p ${OBJTREE}/include
mkdir -p ${OBJTREE}/include2
cd ${OBJTREE}/include2
rm -f asm
ln -s ${SRCTREE}/include/asm-$2 asm
LNPREFIX="../../include2/asm/"
cd ../include
rm -rf asm-$2
rm -f asm
mkdir asm-$2
ln -s asm-$2 asm
else
cd ./include
rm -f asm
ln -s asm-$2 asm
fi
rm -f asm-$2/arch
if [ -z "$6" -o "$6" = "NULL" ] ; then
ln -s ${LNPREFIX}arch-$3 asm-$2/arch
else
ln -s ${LNPREFIX}arch-$6 asm-$2/arch
fi
if [ "$2" = "arm" ] ; then
rm -f asm-$2/proc
ln -s ${LNPREFIX}proc-armv asm-$2/proc
fi
#
# Create include file for Make
#
echo "ARCH = $2" > config.mk
echo "CPU = $3" >> config.mk
echo "BOARD = $4" >> config.mk
[ "$5" ] && [ "$5" != "NULL" ] && echo "VENDOR = $5" >> config.mk
[ "$6" ] && [ "$6" != "NULL" ] && echo "SOC = $6" >> config.mk
#
# Create board specific header file
#
if [ "$APPEND" = "yes" ] # Append to existing config file
then
echo >> config.h
else
> config.h # Create new config file
fi
echo "/* Automatically generated - do not edit */" >>config.h
echo "#include <configs/$1.h>" >>config.h
exit 0
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