为BBB编译内核和Linux

Nov 9, 2014
Technology

因为原文是英文的缘故，所以这里就直接用中文翻译，并把编译时的步骤和注意事项记载下来。
主要参考了:
https://eewiki.net/display/linuxonarm/BeagleBone+Black
All of the files and folder are located under $BBB/201411 folder.

交叉编译链准备

下载、设置交叉编译链:

wget -c https://releases.linaro.org/14.09/components/toolchain/binaries/gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux.tar.xz
tar xf gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux.tar.xz
export CC=`pwd`/gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux/bin/arm-linux-gnueabihf-

测试交叉编译链:

# ${CC}gcc --version
arm-linux-gnueabihf-gcc (crosstool-NG linaro-1.13.1-4.9-2014.09 - Linaro GCC 4.9-2014.09) 4.9.2 20140904 (prerelease)
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

编译U-Boot

下载U-Boot:

git clone git://git.denx.de/u-boot.git
cd u-boot/
git checkout v2014.10 -b tmp

下载、加载补丁:

wget -c https://raw.githubusercontent.com/eewiki/u-boot-patches/master/v2014.10/0001-am335x_evm-uEnv.txt-bootz-n-fixes.patch
patch -p1 < 0001-am335x_evm-uEnv.txt-bootz-n-fixes.patch

编译U-Boot:

# make ARCH=arm CROSS_COMPILE=${CC} distclean && make ARCH=arm CROSS_COMPILE=${CC} am335x_evm_defconfig && make ARCH=arm CROSS_COMPILE=${CC}

编译内核

下面的步骤将编译出内核和内核模块，编译完成后全部被拷贝到deploy文件夹中。

主线内核

编译前准备，在Ubuntu 12.04，安装下列包:

$ sudo apt-get install bc build-essential device-tree-compiler fakeroot lzma lzop man-db u-boot-tools libncurses5-dev ia32-libs wget

下载:

$ git clone https://github.com/RobertCNelson/bb-kernel.git
$ cd bb-kernel/

切换到v3.8.x分支(支持全面):

$ git checkout origin/am33x-v3.8 -b tmp

切换到v3.17.x分支(SGX，更好的usb和Ethernet支持), SGX，硬件加速。

$ git checkout origin/am33x-v3.17 -b tmp

编译：

$ ./build_kernel.sh

TI内核

完整编译步骤如下：

git clone https://github.com/RobertCNelson/ti-linux-kernel-dev/
cd ti-linux-kernel-dev/
git checkout origin/ti-linux-3.14.y -b tmp
./build_kernel.sh

准备文件系统

Ubuntu

下载并解压Ubuntu文件系统:

wget -c https://rcn-ee.net/deb/minfs/trusty/ubuntu-14.04-minimal-armhf-2014-07-07.tar.xz
tar xf ubuntu-14.04-minimal-armhf-2014-07-07.tar.xz

写入存储卡

分区准备

准备的TF卡容量为8G，使用lsblk可以用于查看device id。

$ lsblk
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
mmcblk0     179:0    0   7.4G  0 disk 
├─mmcblk0p1 179:1    0    48M  0 part 
└─mmcblk0p2 179:2    0   7.4G  0 part

备份好TF卡上文件内容后，对其重新进行分区，这里使用fdisk移除掉所有分区后重新分成一个区，而后格式化为ext4分区。

# export DISK=/dev/mmcblk0
# sudo dd if=/dev/zero of=${DISK} bs=1M count=10
# sudo dd if=./u-boot/MLO of=${DISK} count=1 seek=1 conv=notrunc bs=128k
# sudo dd if=./u-boot/u-boot.img of=${DISK} count=2 seek=1 conv=notrunc bs=384k
# sudo sfdisk --in-order --Linux --unit M ${DISK} <<-__EOF__
1,,0x83,*
__EOF__
# sudo mkfs.ext4 /dev/mmcblk0p1 -L rootfs

现在查看lsblk的结果应该是这样:

mmcblk0     179:0    0   7.4G  0 disk 
└─mmcblk0p1 179:1    0   7.4G  0 part

写入

我们将使用eMMC自有的BootLoader, 所以在/media/rootfs中使用下列内容到uEnv.txtt：

##This will work with: Angstrom's 2013.06.20 u-boot.
 
loadaddr=0x82000000
fdtaddr=0x88000000
rdaddr=0x88080000
 
initrd_high=0xffffffff
fdt_high=0xffffffff
 
loadximage=load mmc 0:1 ${loadaddr} /boot/vmlinuz-${uname_r}
loadxfdt=load mmc 0:1 ${fdtaddr} /boot/dtbs/${uname_r}/${fdtfile}
loadxrd=load mmc 0:1 ${rdaddr} /boot/initrd.img-${uname_r}; setenv rdsize ${filesize}
loaduEnvtxt=load mmc 0:1 ${loadaddr} /boot/uEnv.txt ; env import -t ${loadaddr} ${filesize};
loadall=run loaduEnvtxt; run loadximage; run loadxfdt;
 
mmcargs=setenv bootargs console=tty0 console=${console} ${optargs} ${cape_disable} ${cape_enable} root=${mmcroot} rootfstype=${mmcrootfstype} ${cmdline}
 
uenvcmd=run loadall; run mmcargs; bootz ${loadaddr} - ${fdtaddr};

解压缩下载好的rootfs文件到SD卡分区：

$ tar xvf armhf-rootfs-ubuntu-trusty.tar -C /media/rootfs/
$ sync

拷贝kernel到SD卡分区:

# cp /media/y/embedded/BBB/201411/deploy/3.14.23-ti-r32.zImage ./vmlinuz-3.14.23-ti-r32

拷贝Kernel Device Tree二进制文件:

tar xvf /media/y/embedded/BBB/201411/deploy/3.14.23-ti-r32-dtbs.tar.gz -C /media/rootfs/boot/dtbs/${kernel_version}/

拷贝内核模块:

# tar xfv /media/y/embedded/BBB/201411/deploy/3.14.23-ti-r32-modules.tar.gz -C /media/rootfs/

配置fstab文件:

sudo sh -c "echo '/dev/mmcblk0p1  /  auto  errors=remount-ro  0  1' >> /media/rootfs/etc/fstab"

配置网络：

# vim /media/rootfs/etc/network/interfaces
auto lo
iface lo inet loopback
 
auto eth0
iface eth0 inet dhcp

配置串口登录：

$ sudo vim /media/rootfs/etc/init/serial.conf
start on stopped rc RUNLEVEL=[2345]
stop on runlevel [!2345]
 
respawn
exec /sbin/getty 115200 ttyO0

进入U-boot后更改一下配置：

U-Boot# setenv mmcroot /dev/mmcblk0p1 ro
U-Boot# boot

默认用户名，密码分别是: root/temppwd
进入系统以后查看系统信息：

ubuntu@arm:~$ uname -a 
Linux arm 3.14.23-ti-r32 #1 SMP PREEMPT Sun Nov 9 04:19:25 UTC 2014 armv7l armv7l armv7l GNU/Linux
ubuntu@arm:~$ cat /etc/issue
Ubuntu 14.04 LTS \n \l

default username:password is [ubuntu:temppwd]
ubuntu@arm:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr 90:59:af:65:d9:8c  
          inet addr:10.0.0.122  Bcast:10.0.0.255  Mask:255.255.255.0

Install new image to sd card for BBB

Nov 8, 2014
Technology

Mainly for installing the OpenWRT system on the BBB, following is the steps:

# zImage
cp /media/y/embedded/BBB/svnco/trunk/bin/omap/openwrt-omap-zImage ./zImage
# dtb file
cp /media/y/embedded/BBB/svnco/trunk/bin/omap/dtbs/am335x-boneblack.dtb ./dtbs/

Setting NFS Server on Ubuntu Container

Nov 8, 2014
Technology

Since there are some strange problems in my ArchLinux(Physical Machine), its nfs server will be ignored by the embedded board, while my joggler which runs ubuntu12.04 acts OK. So I try to find a sufficient way for dealing with this issue.

Container Configuration

I’ve installed Ubuntu_Container which holds 12.04 in my physical machine. So the nfs server would be configured in this container.

$ sudo apt-get update
$ sudo apt-get install nfs-kernel-server portmap nfs-common

Then edit the /srv/nfs4, and export its configuration in /etc/exports:

/srv/nfs4 *(rw,sync,no_root_squash,no_subtree_check)

Everytime you want to start the nfs service, just type:

$ /etc/init.d/nfs-kernel-server restart
$ /etc/init.d/portmap restart

Test

Client run:

sudo mount -t nfs 1xx.xx.xx.xx:/srv/nfs4/ /mnt

Trouble-Shooting

The correct parameter for mounting the nfs server is:

setenv bootargs console=ttyO0,115200n8 root=/dev/nfs rw nfsroot=192.168.1.221:/srv/nfs4/BBBrootfs ip=192.168.1.1

Then you won’t have other problems, even the physical machine could also use the nfs filesystem.

Automatically Filter SpamBot on DigitalOcean

Nov 6, 2014
Technology

Setup iptables

Install iptables-persistent, so that the iptables rules will be saved even reboot the machine:

# apt-get update
# apt-get install iptables-persistent

Script for manually add iptables

Use following scritp for manually add iptables items:

#!/bin/sh
# This script runs once per hour, Directly remove the ips which post comments
# more than 4 times per hour. And who comments less than 3 times we should sent
# its ip to old ips file. The old ips files will be used for analyse once per day
# The run frequency is controlled by  crontab.   

######################################################
# Before Start, empty the deathSentence
######################################################
>/var/log/apache2/deathSentence

######################################################
# First cat the file and try to found the bot ip list
######################################################
# Pipe 1: The one who called POST method should be monitored
# Pipe 2: Get the ip address who called POST method.
# Pipe 3: Sort the ip addresses. 
# Pipe 4: Calculate the repeated times. First column, times; Second column, ip address.
# Pipe 5: Sort via first column(times) numerically(Not textly!) .
# Pipe 6: If the Call POST time bigger than 4 in one hour, catch it!
# Pipe 7: Yes we caught this thief! Get its ipaddr.
# Write these thieves into the death sentence
cat /var/log/apache2/other_vhosts_access.log | grep "POST" | awk '{print $2}' | sort | uniq --count | sort -n | awk '$1>4' | awk {'print $2'}>/var/log/apache2/deathSentence
# Those who comments but equal or more than 4 times will be append to wishList
cat /var/log/apache2/other_vhosts_access.log | grep "POST" | awk '{print $2}' | sort | uniq --count | sort -n | awk '$1<5' | awk {'print $2'}>>/var/log/apache2/wishList

######################################################
# Second we add this bot ip list into the netfilter
######################################################
for i in `cat /var/log/apache2/deathSentence`
do
	#echo $i
	iptables -A INPUT -s $i -j DROP
done

######################################################
# Finally empty the other_vhosts_access.log
######################################################
>/var/log/apache2/other_vhosts_access.log

Oh, also add myself into the blacklist, so un-lock me:

$ iptables -A INPUT -s 1xx.x.x.x -j ACCEPT

Since those wishList should also be cared, wrote following scripts for judge, every 4 hours will be make a decision.

#!/bin/sh
# This script runs once 4 hours, used for processing the /var/log/apache2/wishList
# ip address lists. Those bad guys who were in wishList, if their total appear times
# bigger than 4 times, will be added to iptable's drop rules.
>/var/log/apache2/deathSentence_4hour

######################################################
# Read the ip list and store those bad guys into deathSentence_4hour
######################################################
cat /var/log/apache2/wishList | sort | uniq --count | sort -n | awk '$1>4' | awk {'$print $2'}>/var/log/apache2/deathSentence_4hour

######################################################
# Now you got the bad guys, add them into iptables
######################################################
for i in `cat /var/log/apache2/deathSentence_4hour`
do
        #echo $i
        iptables -A INPUT -s $i -j DROP
done

######################################################
# Finally empty the wishList
######################################################
>/var/log/apache2/wishList

Crontab It!

Run auto_add_bot_ip.sh at every minute 0 of 1 hour, then run auto_judge_wishlist.sh at every minute 10 of every 4 hours.

# m h  dom mon dow   command
0 */1 * * * /root/code/auto_add_bot_ip.sh
10 */4 * * * /root/code/auto_judge_wishlist.sh

Manually delete spam comments for WP