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 2013-023)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 = 0num= 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 ~]# ls -l /dev/nand*brw------- 1 root root 93, 0 Jan 1 1970 /dev/nandbrw------- 1 root root 93, 1 Jan 1 1970 /dev/nandabrw------- 1 root root 93, 2 Jan 1 1970 /dev/nandbbrw------- 1 root root 93, 3 Jan 1 1970 /dev/nandcbrw------- 1 root root 93, 4 Jan 1 1970 /dev/nanddbrw------- 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 = bootloaderpkt_name = BOOTLOADER_00000encrypt = 0[download1]part_name = envpkt_name = ENVIROMENT_00000encrypt = 0[download2]part_name = bootpkt_name = KERNEL_000000000encrypt = 0[download3]part_name = rootfspkt_name = ROOTFS_000000000encrypt = 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sharee)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.gitcommit 9d0aaa64c5bd034f1f53dd5889f7a77af0da40fdAuthor: 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_defconfigindex 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=yBR2_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 viewersdiff --git a/package/Config.in b/package/Config.inindex 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"endmenumenu "Text editors and viewers"diff --git a/package/cb_tools/Config.in b/package/cb_tools/Config.innew file mode 100644index 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.mknew file mode 100644index 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+endifdiff --git a/package/cb_tools/src/Makefile b/package/cb_tools/src/Makefilenew file mode 100644index 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.cnew file mode 100644index 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-daemoncat /tools/ir-hook #!/bin/bashif [ "$2" -eq "1" ]; thenif cat /sys/class/leds/blue\:ph21\:led2/brightness|grep 1thenecho 0 > /sys/class/leds/blue\:ph21\:led2/brightnesselseecho 1 > /sys/class/leds/blue\:ph21\:led2/brightnessfifi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/bashif [ "$2" -eq "0" ]; then exit 0fiif ! ls /sys/class/gpio |grep gpio30then 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/directionfiif cat /sys/class/gpio/gpio31_pd1/value |grep 1then echo 0 > /sys/class/gpio/gpio30_pd2/value echo 0 > /sys/class/gpio/gpio31_pd1/valueelse echo 0 > /sys/class/gpio/gpio30_pd2/value echo 1 > /sys/class/gpio/gpio31_pd1/valuefigpio映射可以看：1) 2)tools/pack/chips/sun4i/configs/linux/cubieboard/sys_config1.fex 其中的gpio_para段3)
原文作者：原文链接：http://forum.cubietech.com/forum.php?mod=viewthread&tid=352&extra=&page=1