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Posted at 5/12/2022 16:49:15
Last edited by tuhn1995 In 5/12/2022 16:51 Editor
Thank you for your answer, I will try it .
But there is one more thing that I want to ask is that when the kernel finish loading and the udev started to populate the /dev directory. It takes a lot of time like 40 secs, showing a promt that udevadm fail and then run a thing call ramdom number generator as can be shown below.
- [ 5.210832] ALSA device list:
- [ 5.214659] #0: rockchip,rk809-codec
- [ 5.376868] Freeing unused kernel memory: 1024K
- NAME=Buildroot
- VERSION=2018.02-rc3-ga31246734b
- ID=buildroot
- VERSION_ID=2018.02-rc3
- PRETTY_NAME="Buildroot 2018.02-rc3"
- Starting logging: OK
- Populating /dev using udev: [ 33.487770] udevd[160]: starting version 3.2.7
- [ 36.790111] udevd[160]: specified group 'kvm' unknown
- [ 41.485961] udevd[161]: starting eudev-3.2.7
- udevadm settle failed</b>
- done
- Initializing random number generator... done.
- Starting network: cmdline=storagemedia=emmc androidboot.storagemedia=emmc androidboot.mode=normal androidboot.slot_suffix= androidboot.serialno=17c5e6b3cec0121 ro rootwait earlycon=uart8250,mmio32,0xff160000 swiotlb=1 console=ttyFIQ0 root=PARTLABEL=rootfs rootfstype=ext4 overlayroot=device:dev=PARTLABEL=userdata,fstype=ext4,mkfs=1 coherent_pool=1m systemd.gpt_auto=0 cgroup_enable=memory swapaccount=1
- read console from cmdline is /dev/ttyFIQ0
- Starting recovery on Sat Aug 5 08:47:18 2017
- Recovery System have UI defined.
- failed to read font: res=-1, fall back to the compiled-in font
- [ 350.000655] Freeing drm_logo memory: 1236K
- rotate degree: 0 - none, 1 - right, 2 - down, 3 - left.
- current rotate degree is : 0
- OK
- Debug: configfs_init
- mkdir: can't create directory '/sys/kernel/config/usb_gadget/rockchip/functions/uac1.gs0': No such file or directory
- mkdir: can't create directory '/sys/kernel/config/usb_gadget/rockchip/functions/uac2.gs0': No such file or directory
- [ 611.974801] file system registered
- mkdir: can't create directory '/sys/kernel/config/usb_gadget/rockchip/functions/mtp.gs0': No such file or directory
- mkdir: can't create directory '/sys/kernel/config/usb_gadget/rockchip/functions/rndis.gs0': No such file or directory
- [ 622.726941] Mass Storage Function, version: 2009/09/11
- [ 622.741869] LUN: removable file: (no medium)
- mkdir: can't create directory '/sys/kernel/config/usb_gadget/rockchip/functions/hid.usb0': No such file or directory
- [ 649.801816] read descriptors
- [ 649.841781] read strings
- [ 655.313572] dwc2 ff300000.usb: bound driver configfs-gadget
- [ 655.626849] dwc2 ff300000.usb: new device is high-speed
- [ 655.734602] dwc2 ff300000.usb: new device is high-speed
- [ 655.802028] dwc2 ff300000.usb: new address 29
- [ 655.841771] configfs-gadget gadget: high-speed config #1: b
- [ 655.904757] android_work: sent uevent USB_STATE=CONNECTED
- [ 655.937750] android_work: sent uevent USB_STATE=CONFIGURED
- Starting input-event-daemon: input-event-daemon: Start parsing /etc/input-event-daemon.conf...
- input-event-daemon: Adding device: /dev/input/event0...
- input-event-daemon: Adding device: /dev/input/event1...
- input-event-daemon: Start listening on 2 devices...
- done
Copy the code
So when the fs is ready, I tried to use ls /dev to see if any device is listed and there are a lot of device there. So why does udevadm fail but there are still device directories in /dev.
I have tried to used another device management method in buildroot menuconfig (dynamic devtmpfs + mdev) but the result is still the same so can you make a guess why populate udev take up such a long time like this. |
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