[教程]使用buildroot完全自定义自己的embedded linux系统(nand)
http://www.eeboard.com/bbs/thread-38377-1-1.html
ubuntu, fedora, debian太过庞大了，你是否想完完全全的构建自己的embedded linux系统？本篇文章教你如何实现
编译环境： ubuntu 12.04(x86_64) 目标环境： 1) linux-3.4内核 2) buildroot 2013-02 3)系统运行在nand上 固件制作步骤说明： 步骤一：创建自己的工作目录 $mkdir ~/mylinux $cd ~/mylinux 步骤二：获取源代码 $git clone git://github.com/cubieboard/sunxi-tools.git tools $git clone git://github.com/cubieboard/u-boot-sunxi.git u-boot $git clone git://github.com/cubieboard/buildroot-sunxi.git buildroot $git clone git://github.com/cubieboard/linux-sunxi.git linux-3.4 步骤三：切换到sunxi-3.4-cb分支 $cd tools $git checkout -b sunxi-3.4-cb origin/sunxi-3.4-cb $cd - $cd u-boot $git checkout -b sunxi-3.4-cb origin/sunxi-3.4-cb $cd - $cd buildroot $git checkout -b sunxi-3.4-cb origin/sunxi-3.4-cb $cd - $cd linux-3.4 $git checkout -b sunxi-3.4-cb origin/sunxi-3.4-cb $cd - 步骤四：编译并生成固件 $cd ~/mylinux $tools/build.sh 漫长的编译完成后，在toosl/pack下面生成了一个100多M的固件 步骤五： 1)启动livesuit，并选中刚生成的固件 2)准备好一块cubieboard，按住micro USB口下面的烧写键，然后插入usb线，等3秒左右，松开按键，进入烧写模式 简易教程已经写完，后续里面各个部分如何定制，以及相关的原理会不断的补充上来，欢迎大家尝试并提出意见 教程二. 定制buildroot $cd ~/mylinux/buildroot $make cubieboard_defconfig $make menuconfig 进入了如下的界面
通过上下左右，空格+返回选中要增加的软件包，定制完成后退出 把新的配置保存下来 $cp .config configs/cubieboard_defconfig 做完后就可以重新运行tools/build.sh重新生成固件了。有一点需要注意的，不要进到tools目录下运行build.sh脚本，必须在~/mylinux目录下，运行tools/build.sh 如果你还想进一步的定制你的文件系统，可以研究下board/cubieboard下面的skel以及scripts脚本，也可以上buildroot的官方网站查看他们的帮助文档 教程三 定制nand分区 1)当前分区情况说明 我们知道, cubieboard上的nandflash的容量是4GB。 当前nand的分区情况可以看～/mylinux/tools/pack/chips/sun4i/configs/linux/default/下面的sys_config.fex文件，如下面所示[part_num] num = 4 [partition0] class_name = DISK name = bootloader size_hi = 0 size_lo = 32768 user_type = 0 ro = 0 [partition1] class_name = DISK name = env size_hi = 0 size_lo = 16384 user_type = 0 ro = 0 [partition2] class_name = DISK name = boot size_hi = 0 size_lo = 16384 user_type = 0 ro = 0 [partition3] class_name = DISK name = rootfs size_hi = 0 size_lo = 524288 user_type = 0 ro = 0 num= 4表示分为4个分区，每个分区的容量由size_lo指定，以1KB为单位。需要注意的是，如果4个分区的容量没有用完4GB（我们的nandflash 是4GB），则烧写的时候会自动添加一个分区，用完所有的nand容量。我们进入linux系统，看一下系统中的分区，如下：[root@linux ~]# ls -l /dev/nand* brw------- 1 root root 93, 0 Jan 1 1970 /dev/nand brw------- 1 root root 93, 1 Jan 1 1970 /dev/nanda brw------- 1 root root 93, 2 Jan 1 1970 /dev/nandb brw------- 1 root root 93, 3 Jan 1 1970 /dev/nandc brw------- 1 root root 93, 4 Jan 1 1970 /dev/nandd brw------- 1 root root 93, 5 Jan 1 1970 /dev/nande 其中/dev/nand表示的是整个nand设备，容量是4GB，nanda,nandb,nandc,nandd是sys_config.fex中配置 的分区，nande是系统计算剩余容量自动创建的。在使用livesuit烧写的时候，每个用户分区要烧写的镜像也是在sys_config.fex中指 定的，如下[down_num] down_num = 4 [download0] part_name = bootloader pkt_name = BOOTLOADER_00000 encrypt = 0 [download1] part_name = env pkt_name = ENVIROMENT_00000 encrypt = 0 [download2] part_name = boot pkt_name = KERNEL_000000000 encrypt = 0 [download3] part_name = rootfs pkt_name = ROOTFS_000000000 encrypt = 0 比如前面的bootloader分区，它的索引名是BOOTLOADER_00000，在相同目录下的image.cfg中找到下面一行{filename = "bootloader.fex", maintype = ITEM_ROOTFSFAT16, subtype = "BOOTLOADER_00000",}, 从上面我们可以发现，bootloader区下载的是bootloader.fex文件，我们可以仔细研究tools/pack/pack脚本，发现 bootloader.fex是fsbuild命令工具创建的一个fat16的文件镜像，它们内容来源于~/mylinux/tools/pack /chips/sun4i/wboot/bootfs。同理，其他的分区文件也可以这样分析。 2）修改指定分区容量大小 这里举个简单的例子，把nandd(也就是我们linux的根分区）容量从原来的512MB调整到2GB ，只需要在sys_config.fex的[partition3] class_name = DISK name = rootfs size_hi = 0 size_lo = 524288 user_type = 0 ro = 0 改为[partition3] class_name = DISK name = rootfs size_hi = 0 size_lo = 2057152 user_type = 0 ro = 0 然后重修执行tools/build.sh,烧写完进入系统，nandd的容量就变成2GB了。 教程四 裁剪linux内核 其实同裁剪buildroot。命令如下$cd ~/mylinux/linux-3.4 $cp arch/arm/configs/cubieboard_defconfig .config $make ARCH=arm menuconfig (注意：不要漏了ARCH=arm) 执行完上面的命令后，则进入经典的NCURSE界面，选上自己喜欢的驱动后，退出，再把新的配置文件保存 $cp .config arch/arm/configs/cubieboard_defconfig 最后在回到mylinux目录，执行tools/build.sh即可。如果需要增加自己的驱动，建议加入到kernel的目录树中，可以参考 linux-3.4/Documentation/kbuild/kconfig-language.txt，有时间研究的话，可以学到很多东西。同时建 议新人好好看一看linux-3.4/Documentation/CodingStyle。 教程五 红外控制例子 在做好自己的系统后，下面我们写一个简单的红外控制计算机的例子（具体控制需要自己实现，这里是一个demo) a)烧写完linux,上电 b)使用root（密码cubieboard)登录 c)连上以太网线 d)挂载开发机 $udhcpc (自动配置ip) $mount.cifs //192.168.1.2/share /mnt -o user=build (假设我的开发主机是192.168.1.2，并有一个共享目录share e)写一段小代码，如下 //ir-demo.c，我直接放到share目录下 //arm-linux-gnueabihf-gcc -static -o ir-demo ir-demo.c#include <stdio.h> #include <stdint.h> #include <linux/input.h> #include <string.h> #include <fcntl.h> #include <unistd.h> #include <sys/types.h> #include <sys/inotify.h> #include <sys/stat.h> #include <limits.h> #include <sys/errno.h> #ifndef EV_SYN #define EV_SYN 0 #endif #define BITS_PER_LONG (sizeof(long) * 8) #define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1) #define OFF(x) ((x)%BITS_PER_LONG) #define BIT(x) (1UL<<OFF(x)) #define LONG(x) ((x)/BITS_PER_LONG) #define EVENT_SIZE ( sizeof (struct inotify_event) ) int main (int argc, char **argv) { int fd, rd, i; struct input_event ev[64]; int version; unsigned short id[4]; unsigned long bit[EV_MAX][NBITS(KEY_MAX)]; char name[256] = "Unknown"; int abs[5]; if (argc < 2) { printf("Usage: ir-runner /dev/input/eventX\n"); return 1; } if ((fd = open(argv[argc - 1], O_RDONLY)) < 0) { perror("evtest"); return 1; } ioctl(fd, EVIOCGNAME(sizeof(name)), name); printf("Input device name: \"%s\"\n", name); daemon(0, 1); while (1) { rd = read(fd, ev, sizeof(struct input_event) * 64); if (rd < (int) sizeof(struct input_event)) { perror("\nir: error reading"); return 1; } for (i = 0; i < rd / sizeof(struct input_event); i++) { printf("code=%d, type=%d, value=%d\n", ev.code, ev.type, ev.value); //可以在这里根据不同的code值执行不同的程序，可以用system系统调用 } } close(fd); return 0; } f) 运行测试程序 #insmod /lib/modules/3.4.29+/kernel/drivers/input/keyboard/sun4i-ir.ko 此时打印提示是event1设备。 #/mnt/ir-demo /dev/input/event1 这个时候按遥控键就有反应了。如果配上LED灯或者GPIO就更佳了。 简化了下前面红外测试代码，并提交到github.com/cubieboard/buildroot-sunxi.git commit 9d0aaa64c5bd034f1f53dd5889f7a77af0da40fd Author: matson <> Date: Sat Apr 27 11:20:55 2013 +0800 cubieboard: add cb_tools package Add ir-daemon example program. This allow you to trigger some other program via IR module. The instructions to do this are: 1. After system startup, insmod sunxi-ir.ko module 2. run 'ir-daemon' 3. Add a hook script or program, and the full name should be '/tools/ir-hook' when you push the IR key, ir-daemon will start '/tools/ir-hook', pass the keycode and value to '/tools/ir-hook' diff --git a/configs/cubieboard_defconfig b/configs/cubieboard_defconfig index 82deac0..68bcb41 100644 --- a/configs/cubieboard_defconfig +++ b/configs/cubieboard_defconfig @@ -1,6 +1,6 @@ # # Automatically generated make config: don't edit -# Buildroot 2013.02-dirty Configuration +# Buildroot 2013.02-00001-g49408af-dirty Configuration # BR2_HAVE_DOT_CONFIG=y BR2_HOSTARCH_NEEDS_IA32_LIBS=y @@ -988,6 +988,7 @@ BR2_PACKAGE_UTIL_LINUX_LIBBLKID=y # BR2_PACKAGE_UTIL_LINUX_LOGIN_UTILS is not set # BR2_PACKAGE_UTIL_LINUX_WRITE is not set # BR2_PACKAGE_DSP_TOOLS is not set +BR2_PACKAGE_CB_TOOLS=y # # Text editors and viewers diff --git a/package/Config.in b/package/Config.in index faee5c3..6aba157 100644 --- a/package/Config.in +++ b/package/Config.in @@ -800,6 +800,7 @@ source "package/supervisor/Config.in" source "package/systemd/Config.in" source "package/util-linux/Config.in" source "package/dsp-tools/Config.in" +source "package/cb_tools/Config.in" endmenu menu "Text editors and viewers" diff --git a/package/cb_tools/Config.in b/package/cb_tools/Config.in new file mode 100644 index 0000000..67943e9 --- /dev/null +++ b/package/cb_tools/Config.in @@ -0,0 +1,5 @@ +config BR2_PACKAGE_CB_TOOLS + bool "cb_tools" + help + tools for cubieboard + diff --git a/package/cb_tools/cb_tools.mk b/package/cb_tools/cb_tools.mk new file mode 100644 index 0000000..20a7ffe --- /dev/null +++ b/package/cb_tools/cb_tools.mk @@ -0,0 +1,28 @@ +CB_TOOLS_DIR := $(BUILD_DIR)/cb_tools + +$(CB_TOOLS_DIR)/.source : + mkdir -pv $(CB_TOOLS_DIR) + cp -rf package/cb_tools/src/* $(CB_TOOLS_DIR) + touch $@ + +$(CB_TOOLS_DIR)/.configured : $(CB_TOOLS_DIR)/.source + touch $@ + + +cb_tools-binary: $(CB_TOOLS_DIR)/.configured + $(MAKE) CC="$(TARGET_CC)" -C $(CB_TOOLS_DIR) + + +cb_tools: cb_tools-binary + $(MAKE) DESTDIR="$(TARGET_DIR)" -C $(CB_TOOLS_DIR) install + rm -rf $(CB_TOOLS_DIR)/.source $(CB_TOOLS_DIR)/.configured + + +############################################################## +# +# Add our target +# +############################################################# +ifeq ($(BR2_PACKAGE_CB_TOOLS),y) +TARGETS += cb_tools +endif diff --git a/package/cb_tools/src/Makefile b/package/cb_tools/src/Makefile new file mode 100644 index 0000000..f70f181 --- /dev/null +++ b/package/cb_tools/src/Makefile @@ -0,0 +1,26 @@ + +#CROSS_COMPILE?=arm-linux-gnueabihf- +#CC=$(CROSS_COMPILE)gcc +#LD=$(CROSS_COMPILE)ld + +#ifneq "CROSS_SYSROOT" "" +#CROSS_SYSROOT=$(shell cd ../../../../out/br/staging; pwd) +#endif + +#CFLAGS+=--sysroot=$(CROSS_SYSROOT) + +ir-daemon:ir-daemon.c + $(CC) $(CFLAGS) -o ir-daemon -lsysfs ir-daemon.c + + +all: ir-daemon + +install: + install ir-daemon $(DESTDIR)/bin + +clean: + rm -rf *.o ir-daemon + +.PHONY: all clean + + diff --git a/package/cb_tools/src/ir-daemon.c b/package/cb_tools/src/ir-daemon.c new file mode 100644 index 0000000..76a58c9 --- /dev/null +++ b/package/cb_tools/src/ir-daemon.c @@ -0,0 +1,106 @@ +#include <stdio.h> +#include <stdint.h> +#include <linux/input.h> +#include <string.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/inotify.h> +#include <sys/stat.h> +#include <limits.h> +#include <sys/errno.h> +#include <sysfs/dlist.h> +#include <sysfs/libsysfs.h> + +#define SUNXI_IR_NAME "sun4i-ir" +#define HOOK_PROGRAM "/tools/ir-hook" + +int get_sunxi_ir_device(char *buf_name, size_t buf_len) +{ + struct sysfs_class *input_class = NULL; + struct dlist *input_devices = NULL; + struct sysfs_class_device *cls_dev = NULL; + struct sysfs_device *tdev = NULL; + struct sysfs_attribute *tattr = NULL; + int ret = -1; + + input_class = sysfs_open_class("input"); + input_devices = sysfs_get_class_devices(input_class); + + dlist_for_each_data(input_devices, cls_dev, struct sysfs_class_device) { + tdev = sysfs_get_classdev_device(cls_dev); + if (tdev != NULL) { + tattr = sysfs_get_device_attr(tdev, "name"); + if (tattr == NULL) + continue; + if (tattr->value == NULL) + continue; + + if (strncmp(tattr->value, SUNXI_IR_NAME, 8)) { + continue; + } + memset(buf_name, buf_len, 0); + strncpy(buf_name, cls_dev->name, buf_len - 1); + ret = 0; + + } + } + + sysfs_close_class(input_class); + return ret; +} + + +int main (int argc, char **argv) +{ + int fd, rd, i, ret; + struct input_event ev[64]; + char name_buf1[128]; + char name_buf2[128]; + + ret = get_sunxi_ir_device(name_buf1, sizeof(name_buf1)); + if (ret) { + printf("Please insmod sunxi-ir.ko\n"); + return -1; + } + + memset(name_buf2, sizeof(name_buf2), 0); + snprintf(name_buf2, sizeof(name_buf2), "/dev/input/%s", name_buf1); + + printf("ir: %s\n", name_buf2); + + if ((fd = open(name_buf2, O_RDONLY)) < 0) { + perror("evtest"); + return 1; + } + + daemon(0, 1); + + while (1) { + rd = read(fd, ev, sizeof(struct input_event) * 64); + + if (rd < (int) sizeof(struct input_event)) { + perror("read"); + return 1; + } + + for (i = 0; i < rd / sizeof(struct input_event); i++) { + if (ev.type == 1) { + if (ev.value == 1) { + printf("IR: %d DOWN\n", ev.code); + } else { + printf("IR: %d UP\n", ev.code); + } + if (!access(HOOK_PROGRAM, X_OK)) { + memset(name_buf1, sizeof(name_buf1), 0); + snprintf(name_buf1, sizeof(name_buf1), "%s %d %d", + HOOK_PROGRAM, ev.code, ev.value); + system(name_buf1); + } + } + } + } + + close(fd); + return 0; +} 编出固件后，在/tools/下面添加ir-hook程序或者脚本就可以了。ir-daemon在收到信号后，会启动/tools/ir-hook，并把code, value作为$1 $2参数传递给它。这样就可以通过红外控制各种东西了。 刚刚更新了linux-sunxi和tools-sunxi，把ir, leds默认编译进linux内核，gpio编译成模块。所以现在取最新的代码，然后添加下面的脚本，就可以红外控制灯了。理论上控制gpio也是一样 的，但记得要加载驱动，并且运行ir-daemon cat /tools/ir-hook #!/bin/bash if [ "$2" -eq "1" ]; then if cat /sys/class/leds/blue\:ph21\:led2/brightness|grep 1 then echo 0 > /sys/class/leds/blue\:ph21\:led2/brightness else echo 1 > /sys/class/leds/blue\:ph21\:led2/brightness fi fi 使用红外控制gpio灯的例子。用了cubieboard的面包板 脚本如下 cat /tools/ir-hook #!/bin/bash if [ "$2" -eq "0" ]; then exit 0 fi if ! ls /sys/class/gpio |grep gpio30 then echo "export 30, 31" echo 30 > /sys/class/gpio/export echo 31 > /sys/class/gpio/export echo out > /sys/class/gpio/gpio30_pd2/direction echo out > /sys/class/gpio/gpio31_pd1/direction fi if cat /sys/class/gpio/gpio31_pd1/value |grep 1 then echo 0 > /sys/class/gpio/gpio30_pd2/value echo 0 > /sys/class/gpio/gpio31_pd1/value else echo 0 > /sys/class/gpio/gpio30_pd2/value echo 1 > /sys/class/gpio/gpio31_pd1/value fi gpio映射可以看： 1) http://linux-sunxi.org/Cubieboard 2)tools/pack/chips/sun4i/configs/linux/cubieboard/sys_config1.fex 其中的gpio_para段 3)http://linux-sunxi.org/GPIO
原文作者：matson 原文链接：http://forum.cubietech.com/forum.php?mod=viewthread&tid=352&extra=&page=1