我正在使用基于linux-mainline内核的 Yocto 映像。我有systemd我创建的嵌入式操作系统。
目的
我有一个连接到主板的 UMTS 加密狗，它将用于usb_modeswitch识别加密狗并wvdial连接到 3G 基础设施。
方法
我写了一个简单的bash脚本/usr/umts.sh如下
#!/bin/bash
sleep 1;
usb_modeswitch --default-vendor 12d1 --default-product 1446 -J
sleep 1;
/usr/bin/tmux new-session -d -s Cloud
/usr/bin/tmux set-option set-remain-on-exit on
/usr/bin/tmux new-window -d -n 'wvdial' -t Cloud:1 'sleep 1; /usr/bin/wvdialconf; /usr/bin/wvdial';
usb_modeswitch将配置 USB 加密狗，下一部分将在其中创建tmux会话和触发器wvdial。
我的systemd脚本如下所示/etc/systemd/system/enable-umts.service
GNU nano 2.2.5 文件：/etc/systemd/system/enable-umts.service
[Unit]
Description=Enable UMTS Dongle for Cloud Connectivity
[Service]
Type=oneshot
ExecStart=/usr/umts.sh
[Install]
WantedBy=default.target
（我已使用 授予脚本执行权chmod +x /usr/umts.sh）
我重新加载了守护进程systemctl daemon-reload并启用了该服务systemctl enable enable-umts.service
并重新启动主板（注意：我只有root在主板上，没有其他user）
事实上，从上面的脚本中dmesg触发了，我看到了相关消息usb_modeswitch
[ OK ] Started Enable UMTS Dongle for Cloud Connectivity.
[ 13.051247] scsi host2: usb-storage 1-1:1.5
[ 13.067326] usb-storage 1-1:1.6: USB Mass Storage device detected
[ 13.074645] scsi host3: usb-storage 1-1:1.6
[ 13.158627] usbcore: registered new interface driver usbserial
[ 13.165501] usbcore: registered new interface driver usbserial_generic
[ 13.174754] usbserial: USB Serial support registered for generic
[ 13.202356] usbcore: registered new interface driver option
[ 13.208714] usbserial: USB Serial support registered for GSM modem (1-port)
[ 13.216468] option 1-1:1.0: GSM modem (1-port) converter detected
[ 13.229840] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB0
[ 13.238774] option 1-1:1.3: GSM modem (1-port) converter detected
[ 13.248906] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB1
[ 13.256172] option 1-1:1.4: GSM modem (1-port) converter detected
[ 13.264467] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB2
[ 14.069960] scsi 2:0:0:0: CD-ROM HUAWEI Mass Storage 2.31 PQ: 0 ANSI: 2
[ 14.088684] scsi 3:0:0:0: Direct-Access HUAWEI TF CARD Storage PQ: 0 ANSI: 2
[ 14.127686] sd 3:0:0:0: [sda] Attached SCSI removable disk
GSM modem (1-port) converter detected
] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB0
[ 13.238774] option 1-1:1.3: GSM modem (1-port) converter detected
[ 13.248906] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB1
[ 13.256172] option 1-1:1.4: GSM modem (1-port) coPassword
但是登录后我尝试列出会话tmux ls，它表明没有创建任何会话。
`脚本实际上并没有失败，服务状态如下：
● enable-umts.service - Enable UMTS Dongle for Cloud Connectivity
Loaded: loaded (/etc/systemd/system/enable-umts.service; enabled; vendor preset: enabled)
Active: inactive (dead) since Thu 2018-05-17 12:52:10 UTC; 4min 51s ago
Process: 214 ExecStart=/usr/umts.sh (code=exited, status=0/SUCCESS)
Main PID: 214 (code=exited, status=0/SUCCESS)
May 17 12:52:09 phyboard-mira-imx6-3 umts.sh[214]: Set up interface 0
May 17 12:52:09 phyboard-mira-imx6-3 umts.sh[214]: Use endpoint 0x01 for message sending ...
May 17 12:52:09 phyboard-mira-imx6-3 umts.sh[214]: Trying to send message 1 to endpoint 0x01 ...
May 17 12:52:09 phyboard-mira-imx6-3 umts.sh[214]: OK, message successfully sent
May 17 12:52:09 phyboard-mira-imx6-3 umts.sh[214]: Reset response endpoint 0x81
May 17 12:52:09 phyboard-mira-imx6-3 umts.sh[214]: Reset message endpoint 0x01
May 17 12:52:09 phyboard-mira-imx6-3 umts.sh[214]: Could not reset endpoint (probably harmless): -99
May 17 12:52:09 phyboard-mira-imx6-3 umts.sh[214]: Device is gone, skip any further commands
May 17 12:52:09 phyboard-mira-imx6-3 umts.sh[214]: -> Run lsusb to note any changes. Bye!
May 17 12:52:10 phyboard-mira-imx6-3 systemd[1]: Started Enable UMTS Dongle for Cloud Connectivity.
如果将脚本/usr/umts.sh作为独立脚本执行，那么实际上它会执行它应该执行的所有操作（打开一个新tmux会话并触发wvdial）
这里有什么问题吗？我尝试增加更多sleep时间，但这也不起作用。遗憾的是，我正在处理的 yocto 图像没有rc.local或可用。cron
答案1
我RemainAfterExit=yes|true在我的systemd脚本中添加如下：
[Unit]
Description=Enable UMTS Dongle for Cloud Connectivity
[Service]
Type=oneshot
ExecStart=/usr/umts.sh
RemainAfterExit=true
[Install]
WantedBy=default.target
添加了脚本的完整路径，umts.sh如下所示：
#!/bin/bash
sleep 1;
/usr/bin/tmux new-session -d -s Cloud
/usr/bin/tmux set-option set-remain-on-exit on
/usr/bin/tmux new-window -d -n 'usb_modeswitch' -t Cloud:2 '/usr/sbin/usb_modeswitch --default-vendor 12d1 --default-product 1446 -J';
/usr/bin/tmux new-window -d -n 'wvdial' -t Cloud:1 'sleep 10; /usr/bin/wvdialconf; /usr/bin/wvdial';
重新加载守护进程
systemctl daemon-reload
并重新启动主板。并发现tmux会话创建并运行完美