BeagleBone Black 安装 OpenWrt

春节在家找到之前的一块 BeagleBone Black，一直吃灰比较可惜，给它刷个 OpenWrt 顶替树莓派，把树莓派腾出来当个游戏机。

What is BeagleBone Black?
BeagleBone Black is a low-cost, community-supported development platform for developers and hobbyists. Boot Linux in under 10 seconds and get started on development in less than 5 minutes with just a single USB cable.
Processor: AM335x 1GHz ARM® Cortex-A8
512MB DDR3 RAM
4GB 8-bit eMMC on-board flash storage
3D graphics accelerator
NEON floating-point accelerator
2x PRU 32-bit microcontrollers
Connectivity
USB client for power & communications
USB host
Ethernet
HDMI
2x 46 pin headers
Software Compatibility
Debian
Android
Ubuntu
Cloud9 IDE on Node.js w/ BoneScript library
plus much more

在给 BBB 安装 OpenWrt 之前，先说说怎么把 Debian、Ubuntu 装到 eMMC。

Debian
1. 先下载 image，”Flasher” Debian images 是可以通过 SD 卡烧写到 eMMC 的版本。
2. 用 etcher 把下载好的 image 烧写到 SD 卡里。
3. 把烧写好的 SD 卡插到卡槽里，按住 SD 卡边上的 S2 开关（这是为了让 BBB 从 SD 卡启动），然后给 BBB 上电。
4. 大概等几十秒左右的时间，4 个 user led 开始跑马灯（烧写 eMMC），等到 led 全灭或者全亮后：断电 -> 拔卡 -> 上电，就会从 eMMC 启动了。
Ubuntu
1. 先读文档，装到 eMMC 的说明
2. 下载 image：wget https://rcn-ee.com/rootfs/2020-03-12/flasher/bone-eMMC-flasher-ubuntu-18.04.4-console-armhf-2020-03-12-2gb.img.xz
3. 之后跟装 Debian 的 2-4 步一致
Ubuntu 更新
1. 下载 image：https://rcn-ee.com/rootfs/ubuntu-armhf/
2. 直接 copy 到一个能启动的 SD 卡里，然后从 SD 卡启动 bbb
3. 执行命令 dd if=xxx.iso of=/dev/mmcblk1 bs=4k conv=fsync 写入 eMMC

安装 OpenWrt 跟安装 Debian 不太一样，主要是 OpenWrt 的 image 不带自动写入 eMMC 的脚本，需要自己手动写，下面是具体步骤。

1. 获取 Image

OpenWrt 是支持 BBB 的，可以在 Table of Hardware 里查到。

官方提供了不怎么有用的说明和编译好的版本：21.02.1，如果不想折腾或者官方的能满足要求，那么 image 就请直接下载官方的使用。

不想用官方的 image 的话就得自己编译了，自己编译需要：Linux 环境、20G 左右的硬盘空间、2-3 小时的时间、科学上网环境，贼费劲。

（更新：可以小媷下 Github 的羊毛，利用 Actions 在线编译。bbb-openwrt-actions）

我是用的 Lean 的源码：lede，官方的也行。

第一次编译大概需要 2-3 小时。

装 Ubuntu 虚拟机：Ubuntu Server 20.04 LTS x64

换清华源后安装工具：

  
$ sudo apt-get update
$ sudo apt-get -y install build-essential asciidoc binutils bzip2 gawk gettext git libncurses5-dev libz-dev patch python3 python2.7 unzip zlib1g-dev lib32gcc1 libc6-dev-i386 subversion flex uglifyjs git-core gcc-multilib p7zip p7zip-full msmtp libssl-dev texinfo libglib2.0-dev xmlto qemu-utils upx libelf-dev autoconf automake libtool autopoint device-tree-compiler g++-multilib antlr3 gperf wget curl swig rsync

clone 源码：git clone https://github.com/coolsnowwolf/lede，进入 lede 目录
修改 feeds.conf.default 文件加入 ssr：src-git helloworld https://github.com/fw876/helloworld

调整编译选项：

  
$ ./scripts/feeds update -a
$ ./scripts/feeds install -a
$ make menuconfig

下载 dl 库：make -j8 download V=s
开始编译：make -j1 V=s
编译结果目录：bin/targets

如果不满意之前的结果，可以二次编译，会快很多。

  
$ cd lede
$ git pull
$ ./scripts/feeds update -a && ./scripts/feeds install -a
$ make defconfig
$ make -j8 download
$ make -j$(($(nproc) + 1)) V=s

如果需要重新配置：

  
$ rm -rf ./tmp && rm -rf .config
$ make menuconfig
$ make -j$(($(nproc) + 1)) V=s

2. 烧录启动

用 etcher 把 image 写到 SD卡里，并插到卡槽里。
Mac 接好串口线（PLC2303）：screen /dev/tty.usbserial-xxxx 115200，板上接法见下图。
按住 S2 给 BBB 上电，观查 OpenWrt 是否能启动，有问题度娘或谷哥。

3. 接入网络

在 BBB 能正常启动的情况下，就可把它接入自己的网络中了。

接入前需要额外检查下 BBB 的 ip 是不是可用，OpenWrt 默认是静态 ip：192.168.1.1，如果它不在自己的子网范围内就需要手动修改下。

文件 /etc/config/network

config interface 'lan'
	...
	option ipaddr '192.168.x.x'
	...

浏览器中访问相应 ip 就能看到登陆界面了。

4. 写入 eMMC

用 dd 是把系统写入 eMMC 的简单办法，缺点就是 eMMC 空间没法完全利用。

把之前烧到 SD 卡的 image 拷备到 BBB 里，然后执行以下命令即可：

  
zcat openwrt-omap-ti_am335x-bone-black-ext4-sdcard.img.gz| dd of=/dev/mmcblk1 bs=4k conv=fsync

别外比较复杂的办法应该可以完全利用 eMMC 空间，我没试。

BeagleBone Black eMMC烧写指南

附上脚本：

  
echo "****************************************************"
echo "****************************************************"
echo ""
echo "Sitara Example Flashing Script - 02/11/2014"
echo ""
 
STARTTIME=$(date +%s)
 
##---------Start of variables---------------------##
 
## Set Server IP here
#SERVER_IP="192.168.100.1"
 
## Names of the images to grab from TFTP server
BOOT_PARTITION="boot_partition.tar.gz"
 
## Rename rootfs as needed depending on use of tar or img
ROOTFS_PARTITION="rootfs_partition.tar.xz"
## ROOTFS_PARTITION="rootfs_partition.img.gz"
 
## Declare eMMC device name here
DRIVE="/dev/mmcblk1"
 
##----------End of variables-----------------------##
 
## TFTP files from host.  Edit the files and host IP address for your application.
## We are grabbing two files, one an archive with files to populate a FAT partion,
## which we will create.  Another for a filesystem image to 'dd' onto an unmounted partition.
## Using a compressed tarball can be easier to implement, however, with a large file system
## with a lot of small files, we recommend a 'dd' image of the partition to speed up writes.
#echo "Getting files from server: ${SERVER_IP}"
#time tftp -b 4096 -g -r ${BOOT_PARTITION} ${SERVER_IP} &
#boot_pid=$!
#time tftp -b 4096 -g -r ${ROOTFS_PARTITION} ${SERVER_IP} &
#rootfs_pid=$!
 
 
## Kill any partition info that might be there
dd if=/dev/zero of=$DRIVE bs=4k count=1
sync
sync
 
## Check to see if the eMMC partitions have automatically loaded from the old MBR.
## This might have occured during the boot process if the kernel detected a filesystem
## before we killed the MBR. We will need to unmount and kill them by writing 4k zeros to the
## partitions that were found.
 
check_mounted(){
  is_mounted=$(grep ${DRIVE}p /proc/mounts | awk '{print $2}')
 
  if grep -q ${DRIVE}p /proc/mounts; then
      echo "Found mounted partition(s) on " ${DRIVE}": " $is_mounted
      umount $is_mounted
      counter=1
      for i in $is_mounted; do \
          echo "4k erase on ${DRIVE}p${counter}"; 
          dd if=/dev/zero of=${DRIVE}p${counter} bs=4k count=1;
          counter=$((counter+1));
      done
  else
      echo "No partition found. Continuing."
  fi
}
 
check_mounted;
 
## Partitioning the eMMC using information gathered.
## Here is where you can add/remove partitions.
## We are building 2 partitions:
##  1. FAT, size = 9 cylinders * 255 heads * 63 sectors * 512 bytes/sec = ~70MB
##  2. EXT3, size = 223 ($CYLINDERS-[9 for fat]) cylinders * 255 heads * 63 sectors * 512 bytes/sec = ~1l.7GB
##
## You will need to change the lines ",9,0c0C,*", "10,,,-" to suit your needs.  Adding is similar,
## but you will need to be aware of partition sizes and boundaries.  Use the man page for sfdisk.
echo "Partitioning the eMMC..."
sfdisk --force /dev/mmcblk1 << EOF
    1,104447,b,*
	,,,
EOF
 
## This sleep is necessary as there is a service which attempts
## to automount any filesystems that it finds as soon as sfdisk
## finishes partitioning.  We sleep to let it run.  May need to
## be lengthened if you have more partitions.
sleep 2
 
## Check here if there has been a partition that automounted.
##  This will eliminate the old partition that gets
##  automatically found after the sfdisk command.  It ONLY
##  gets found if there was a previous file system on the same
##  partition boundary.  Happens when running this script more than once.
##  To fix, we just unmount and write some zeros to it.
check_mounted;
 
## Clean up the dos (FAT) partition as recommended by SFDISK
dd if=/dev/zero of=${DRIVE}p1 bs=512 count=1
 
## Make sure posted writes are cleaned up
sync
sync
 
## Format the eMMC into 2 partitions
echo "Formatting the eMMC into 2 partitions..."
 
## Format the boot partition to fat32
mkfs.vfat -F 32 -n "boot" ${DRIVE}p1
 
## Format the rootfs to ext3 (or ext4, etc.) if using a tar file.
## We DO NOT need to format this partition if we are 'dd'ing an image
## Comment out this line if using 'dd' of an image.
mkfs.ext3 -L "rootfs" ${DRIVE}p2
 
## Make sure posted writes are cleaned up
sync
sync
echo "Formatting done."
 
## Make temp directories for mountpoints
mkdir tmp_boot
 
## Comment this line out if using 'dd' of an image. It is not needed.
mkdir tmp_rootfs
 
## Mount partitions for tarball extraction. NOT for 'dd'.
mount -t vfat ${DRIVE}p1 tmp_boot
 
## If 'dd'ing the rootfs, there is no need to mount it. Comment out the below.
mount -t ext3 ${DRIVE}p2 tmp_rootfs
 
## Wait for boot to finish tftp
echo "Copying Boot Files..."
time tar -xf ${BOOT_PARTITION} -C tmp_boot
sync
sync
umount ${DRIVE}p1
#rm ${BOOT_PARTITION}
 
sync
sync
 
echo "Boot partition done."
 
## Wait for rootfs to finish tftp
wait $rootfs_pid
## If using a tar archive, untar it with the below.
## If using 'dd' of an img, comment these lines out and use the below.
echo "Copying Rootfs Files..."
time tar -xf ${ROOTFS_PARTITION} -C tmp_rootfs
sync
sync
umount ${DRIVE}p2
#rm ${ROOTFS_PARTITION}
 
sync
sync
 
echo "RootFS partition done."
 
## If using 'dd' of an img, uncomment these lines.
## If using a tar archive, comment out these lines and use the above.
## time gunzip -c ${ROOTFS_PARTITION} | dd of=${DRIVE}p2 bs=4k
## sync
## sync
## echo "Rootfs partition done."
 
## The block below is only necessary if using 'dd'. 
## Force check the filesystem for consistency and fix errors if any.
## Resize partition to the length specified by the MBR.
## /sbin/e2fsck -fy ${DRIVE}p2
## /sbin/resize2fs ${DRIVE}p2
 
ENDTIME=$(date +%s)
echo "It took $(($ENDTIME - $STARTTIME)) seconds to complete this task..."
## Reboot
echo ""
echo "********************************************"
echo "Sitara Example Flash Script is complete."
echo ""

BeagleBone Black 安装 OpenWrt

What is BeagleBone Black?

Processor: AM335x 1GHz ARM® Cortex-A8

Connectivity

Software Compatibility

1. 获取 Image

2. 烧录启动

3. 接入网络

4. 写入 eMMC

Further Reading

树莓派安装 OpenWrt

BeagleBone Black 板载 LED

BeagleBone Black Lessons