uboot修改移植开发知识梳理

精品文档u-boot修改移植开发知识梳理 /* u-boot裁剪* */board->只留与扳机相关的文件夹cpu ->只留与扳机相关的文件夹include->与架构无关的目录删除include/configs ->只留架构相关的一个文件include/asm->删除与架构无关的目录./->主目录lib开头与架构无关的目录删除，注意报libfdt留下/* makefile 关键说明* */make ming2440_config流程:make mini2440_config-> mini2440_config:unconfig$(MKCONFIG) $(:_config=) arm arm920t mini2440 risecomm s3c24x0-> mkconfigmini2440_config:unconfig$(MKCONFIG) $(:_config=) arm arm920t mini2440 risecomm s3c24x0/ $(A:patternA=patternB)。意思就是将 A中 patternA格式的字符用patternB来代替。回归$(:_config)，/ 代表输入的参数，即：mini2440_config，patternA是_config，patternB是空的。说白了就是将mini2440_config的_config去掉。$(MKCONFIG) $(:_config=) arm arm920t mini2440 tekkamanninja s3c24x0 / 查找MKCONFIG，MKCONFIG就是uboot目录下的那个mkconfig这个文件，这条语句就是：运行mkconfig文件，并传递 6个参数进去mkconfig文件：作用：建立include目录下的link目录(asm)，include目录下创建confg.mk文件，创建config.h文件。APPEND=no# Default: Create new config file BOARD_NAME="" # Name to print in make output TARGETS="" while $# -gt 0 ; do case "$1" in -) shift ; break ; -a) shift ; APPEND=yes ; -n) shift ; BOARD_NAME="$1%_config" ; shift ; -t) shift ; TARGETS="echo $1 | sed s:_: :g $TARGETS" ; shift ; *) break ; esac done / $#是脚本传递的参数的个数。-gt是>的意思。 $1：第一个参数。shift：奸杀第一个参数，/ 将第二参数变成第一个这段代码意思 检查参数中，有无-a -n -t这样的参数，没有的话直接break。 / 很明显，makefile传递的6个参数，没有-a，-t，-n。直接break。 "$BOARD_NAME" | BOARD_NAME="$1"/ ："$BOARD_NAME"表示一个条件，BOARD_NAME != NULL, |表示如果 条件为假 则运行后面的程序。 同时&&表示如果条件为真，则运行后面的程序/ BOARD_NAME等于传进来的第一个参数，即BOARD_NAME=mini2440 $# -lt 4 && exit 1/ 小于4个参数则退出 $# -gt 6 && exit 1/ 大于6个参数则退出if "$ARCH" -a "$ARCH" != "$2" ; then/ 判断ARCH变量值是否为BULL ，-a是and的意思，并且 ARCH！= $2echo "Failed: $ARCH=$ARCH, should be $2 for $BOARD_NAME" 1>&2 exit 1 fi echo "Configuring for $BOARD_NAME board." / 建立 asm连接/ Create link to architecture specific headers/ if "$SRCTREE" != "$OBJTREE" ; then/都为null，相等，所以运行else后面mkdir -p $OBJTREE/includemkdir -p $OBJTREE/include2cd $OBJTREE/include2rm -f asmln -s $SRCTREE/include/asm-$2 asmLNPREFIX="././include2/asm/"cd ./includerm -rf asm-$2rm -f asmmkdir asm-$2ln -s asm-$2 asmelsecd ./includerm -f asmln -s asm-$2 asmfirm -f asm-$2/archif -z "$6" -o "$6" = "NULL" ; then/ -z的意思是判断字符串是否为"" -o是或的意思, 判断语句意思是$6="" 或者$6=NULL ln -s $LNPREFIXarch-$3 asm-$2/archelseln -s $LNPREFIXarch-$6 asm-$2/arch/ asm-arm下建立连接文件arch，link到arch-s3c24x0fiif "$2" = "arm" ; thenrm -f asm-$2/procln -s $LNPREFIXproc-armv asm-$2/procfi# 把芯片信息输出到config.mk文件中# Create include file for Make#echo "ARCH = $2" > config.mkecho "CPU = $3" >> config.mkecho "BOARD = $4" >> config.mk "$5" && "$5" != "NULL" && echo "VENDOR = $5" >> config.mk "$6" && "$6" != "NULL" && echo "SOC = $6" >> config.mk# Assign board directory to BOARDIR variableif -z "$5" -o "$5" = "NULL" ; thenBOARDDIR=$4elseBOARDDIR=$5/$4fi/* u-boot支持go命令的方法* 在cmd_boot.c文件中（没有就自己创建）增加以下内容*/* 1、添加call_linux函数*/void call_linux(long a0, long a1, long a2)_asm_( " mov r1, #0n" " mov r1, #7 << 5n" /* 8 segments */ "1: orr r3, r1, #63 << 26n" /* 64 entries */ "2: mcr p15, 0, r3, c7, c14, 2n" /* clean & invalidate D index */ " subs r3, r3, #1 << 26n" " bcs 2bn" /* entries 64 to 0 */ " subs r1, r1, #1 << 5n" " bcs 1bn" /* segments 7 to 0 */ " mcr p15, 0, r1, c7, c5, 0n" /* invalidate I cache */ " mcr p15, 0, r1, c7, c10, 4n" /* drain WB */); _asm_("mov r0, #0n""mcr p15, 0, r0, c7, c10, 4n" /* drain WB */"mcr p15, 0, r0, c8, c7, 0n" /* invalidate I & D TLBs */);/ 以上的内容可以不要/ r0、r1、r2三个寄存器的参数是传递到内核head.S文件中，r0:0，r1:体系结构号，r2地址_asm_("mov r0, %0n"/ 获取0号，也就是第一个（a0）的数据"mov r1, #0x0c1n"/ 查芯片相关资料，mini2440的为 1999"mov r2, %2n"/ 启动地址 mini2440=0x30008000"mov ip, #0n""mcr p15, 0, ip, c13, c0, 0n" /* zero PID */"mcr p15, 0, ip, c7, c7, 0n" /* invalidate I,D caches */"mcr p15, 0, ip, c7, c10, 4n" /* drain write buffer */ "mcr p15, 0, ip, c8, c7, 0n" /* invalidate I,D TLBs */"mrc p15, 0, ip, c1, c0, 0n" /* get control register */"bic ip, ip, #0x0001n" /* disable MMU */"mcr p15, 0, ip, c1, c0, 0n" /* write control register */"mov pc, r2n""nopn""nopn": /* no outpus */: "r" (a0), "r" (a1), "r" (a2);/*2、添加setup_linux_param函数*/static void setup_linux_param(ulong param_base) struct param_struct *params = (struct param_struct *)param_base; char *linux_cmd; / 获取bootargs参数linux_cmd = getenv("bootargs");memset(params, 0, sizeof(struct param_struct); params->u1.s.page_size = 0x00001000;/ DDR的页大小params->u1.s.nr_pages = (0x04000000 >> 12);/ 页数/* set linux command line */memcpy(params->commandline, linux_cmd, strlen(linux_cmd) + 1);/* u-boot中MAC地址设置及往内核中传递* */1.解决uboot命令行中不能设置ethaddr的问题，经常会提示:Cant overwrite "ethaddr"：common/cmd_nvedit.c中函数_do_setenv中找到189 #ifndef CONFIG_ENV_OVERWRITE190191 /*192 * Ethernet Address and serial# can be set only once,193 * ver is readonly.194 */195 #ifdef CONFIG_HAS_UID196 /* Allow serial# forced overwrite with 0xdeaf4add flag */197 if ( (strcmp (name, "serial#") = 0) && (flag != 0xdeaf4add) |198 #else199 if ( (strcmp (name, "serial#") = 0) |200 #endif201 (strcmp (name, "ethaddr") = 0)202203 #if defined(CONFIG_OVERWRITE_ETHADDR_ONCE) && defined(CONFIG_ETHADDR)204 && (strcmp (char *)env_get_addr(oldval),MK_STR(CONFIG_ETHADDR) != 0)205 #endif /* CONFIG_OVERWRITE_ETHADDR_ONCE && CONFIG_ETHADDR */206 ) ) 207 printf ("Cant overwrite "%s"n", name);208 return 1;209 210 #endif把201行替换成 (0 即可；2.为了让uboot命令行中设置的参数ethaddr传递到内核，必须修改uboot和linux内核两个地方：（1）uboot修改 ： lib_arm/armlinux.c在 247 #ifdef CONFIG_CMDLINE_TAG248 setup_commandline_tag (bd, commandline);下面添加如下语句：char *buf1 = malloc(1024);sprintf(buf1, "%s mac=%s", getenv ("bootargs"), getenv ("ethaddr");setup_commandline_tag (bd, buf1);（2）linux内核修改：drivers/net/davinci_emac.cstatic int emac_eth_setup(void)1899 前面添加：static char davinci_mac_addr_uboot20 = ""1887 static int _init param_mac_setup(char *str)1888 1889 strncpy (davinci_mac_addr_uboot, str, sizeof(davinci_mac_addr_uboot);1890 1891 _setup("mac=", param_mac_setup);并在函数emac_eth_setup内部语句printk("TI DaVinci EMAC: MAC address is %sn", emac_eth_string);前面添加：strncpy(emac_eth_