启动和用户数据更新
<h3>挂载nfs</h3>
<p>设置环境变量后保存<code>saveenv</code></p>
<pre><code>setenv bootargs 'console=${console},${baudrate} root=/dev/nfs rw
nfsroot=${serverip}:${root_path}ip=${ipaddr}:${serverip}:${gw-ip}:${netmask}:${hostname}:${device}:off'
setenv bootargs 'console=ttymxc0,115200 root=/dev/nfs rw nfsroot=192.168.1.137:/nfsroot/rootfs
ip=192.168.1.136:192.168.1.137:192.168.1.254:255.255.255.0:EPC-M6G2C:eth0:off'
</code></pre>
<p>恢复</p>
<pre><code>setenv bootargs 'console=ttymxc0,115200 ubi.mtd=5 ro root=ubi0:rootfs rootfstype=ubifs
g_mass_storage.stall=0 g_mass_storage.removable=1 g_mass_storage.idVendor=0x066F
g_mass_storage.idProduct=0x37FF g_mass_storage.iSerialNumber=""'</code></pre>
<h3>网络启动</h3>
<pre><code>MX6UL > setenv ethaddr 00:01:02:03:04:05 # 设定以太网口 MAC 地址
MX6UL > setenv ipaddr 192.168.1.136 # EPC-6G2C-L 的 IP 地址
MX6UL > setenv serverip 192.168.1.137 # ubuntu 主机的 IP 地址
MX6UL > ping 192.168.1.137 # 测试与 ubuntu 主机的网络通路
Using FEC1 device
host 192.168.1.137 is alive
MX6UL > setenv root_path /nfsroot/rootfs # NFS 根文件系统在 ubuntu 主机中的路径
MX6UL > setenv gw-ip 192.168.1.254 # 网关 IP 地址
MX6UL > setenv netmask 255.255.255.0 # 子网掩码
MX6UL > saveenv # 保存参数设定
Saving Environment to NAND...
Erasing NAND...
MX6UL > run netboot
Booting from net ...
Using FEC1 device
TFTP from server 192.168.1.137; our IP address is 192.168.1.136
Filename 'zImag</code></pre>
<pre><code>setenv bootcmd ‘run netboot’
MX6UL >saveenv</code></pre>
<h3>网络升级内核和文件系统</h3>
<p>1.设置网络</p>
<pre><code>MX6UL> printenv fdt_file # 查看更新的 dtb 文件
MX6UL >run updtb #更新 dtb，可通过设置 fdt_file 变量更改 dtb 文件
Using FEC1 device
TFTP from server 192.168.1.137; our IP address is 192.168.1.136
Filename 'imx6g2c.dtb'.
Load address: 0x80800000
Loading: ###
1.2 MiB/s
done
Bytes transferred = 35322 (9fa hex)
NAND erase.part: device 0 offset 0x400000, size 0x100000
Erasing at 0x4e0000 -- 100% complete.
OK
NAND write: device 0 offset 0x400000, size 0x89fa
35322 bytes written: OK
MX6UL >run uplogo # 更新 LOGO
Using FEC1 device
TFTP from server 192.168.1.137; our IP address is 192.168.1.136
Filename 'logo.bmp'.
Load address: 0x80800000
Loading: #########
1.4 MiB/s
MX6UL >run upkernel # 更新 kernel
Using FEC1 device
TFTP from server 192.168.1.137; our IP address is 192.168.1.136
Filename 'zImage'
MX6UL >run uprootfs # 更新 rootfs
Using FEC1 device
TFTP from server 192.168.1.137; our IP address is 192.168.1.136
Filename 'rootfs.ubifs.img</code></pre>
<p>若tftp服务器根目录下没有放入相应文件将提示错误</p>
<h3>系统启动后更新内核和uboot</h3>
<p>使用freescale官方工具<code>kobs-ng</code>烧录<code>uboot</code>到<code>flash</code>,dtb和内核文件通过<code>nandwrite</code>写入</p>
<pre><code>[root@EPC-M6G2C ~]# ls /opt/
u-boot.imx # 新的 uboot 文件
[root@EPC-M6G2C ~]# mount -t debugfs debugfs /sys/kernel/debug #获取 NAND 的 BCH 布局
[root@EPC-M6G2C ~]# flash_erase /dev/mtd0 0 0 # 擦除旧的 uboot
Erasing 128 Kibyte @ 3e0000 -- 100 % complete
[root@EPC-M6G2C ~]# wr kobs-ng init -x -v --chip_0_device_path=/dev/mtd0 /opt/u-boot.imx # 注意双横杠
省略输出
[root@EPC-M6G2C ~]# sync # 同步 NAND Flash</code></pre>
<h3>rtlinux</h3>
<p><a href="https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git">https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git</a>
实时系统补丁https://mirrors.edge.kernel.org/pub/linux/kernel/projects/rt/
<a href="https://mirrors.edge.kernel.org/pub/linux/kernel/">https://mirrors.edge.kernel.org/pub/linux/kernel/</a></p>
<p>rt-tests测试工具下载: git clone git://git.kernel.org/pub/scm/linux/kernel/git/clrkwllms/rt-tests.git</p>
<p><a href="https://rt.wiki.kernel.org/index.php/Main_page">https://rt.wiki.kernel.org/index.php/Main_page</a></p>
<p><a href="https://lwn.net/Articles/572740/">https://lwn.net/Articles/572740/</a>
<a href="https://lwn.net/Articles/143323/">https://lwn.net/Articles/143323/</a>
<a href="https://lwn.net/Articles/146861/">https://lwn.net/Articles/146861/</a></p>
<h4>安装rtlinux</h4>
<p><a href="https://github.com/yongjianchn/rtlinux-learning/blob/master/HOWTO.md">https://github.com/yongjianchn/rtlinux-learning/blob/master/HOWTO.md</a></p>
<h4>实时系统需要的属性</h4>
<ul>
<li>服务质量</li>
<li>必须检查的代码量以确保服务质量</li>
<li>提供 API</li>
<li>操作系统和应用程序的相对复杂性</li>
<li>故障隔离：哪些非RT故障危及 RT 代码？</li>
<li>支持哪些硬件和软件配置？</li>
</ul>