On Wed, Sep 23, 2020, 09:21 ZhouPeng <zhoupengwork01@xxxxxxx> wrote:
Thank you very much for you great suggestions.
I chroot the rootfs and tried to the 3 methods in '/usr/lib/udev/rules.d' respectively:
try 1) add a line of ACTION!="remove", KERNEL=="ttyPS0", TAG+="systemd" below the line of "ACTION="" GOTO="systemd_end"" in file 99-systemd.rules
try 2) add a line of ACTION!="remove", KERNEL=="ttyPS0", NAME="ttyPS0", TAG+="systemd" below the line of "ACTION="" GOTO="systemd_end"" in file 99-systemd.rules
try 3) replace the line "SUBSYSTEM=="tty", KERNEL=="tty[a-zA-Z]*|hvc*|xvc*|hvsi*|ttysclp*|sclp_line*|3270/tty[0-9]*", TAG+="systemd" with "SUBSYSTEM=="tty", KERNEL=="ttyPS[0-9]|tty[a-zA-Z]*|hvc*|xvc*|hvsi*|ttysclp*|sclp_line*|3270/tty[0-9]*", TAG+="systemd"", in file 99-systemd.rules.
At least the 1st one *should* have worked, though NAME= seems wrong in the 2nd one...
At the same time, I replace the line of "KERNEL=="tty[A-Z]*[0-9]|ttymxc[0-9]*|pppox[0-9]*|ircomm[0-9]*|noz[0-9]*|rfcomm[0-9]*", GROUP="dialout"" with "KERNEL=="ttyPS[0-9]|tty[A-Z]*[0-9]|ttymxc[0-9]*|pppox[0-9]*|ircomm[0-9]*|noz[0-9]*|rfcomm[0-9]*", GROUP="dialout"".
This line is irrelevant, since TAG+="systemd" is the important part – groups and modes shouldn't be the problem.
But they didn't take any effect.
Then at the same time, I do
cp /usr/lib/systemd/system/serial-getty@.service /etc/systemd/system/serial-getty@ttyPS0.service
Edit /etc/systemd/system/serial-getty\@ttyPS0.service: replace "ExecStart=-/sbin/agetty --keep-baud 115200,38400,9600 %I $TERM" with "ExecStart=-/sbin/agetty --keep-baud 115200 %I $TERM"
ln -s /etc/systemd/system/serial-getty@ttyPS0.service /etc/systemd/system/getty.target.wants/
But there was still no effect. There is still boot failure logs like:
[ *] (3 of 3) a start job is running for dev-ttyPS0.device (41s / 1min 30s)// **here**
...
[ TIME ] Timed out waiting for device dev-ttyPS0.device. // **here**
...
Yeah, the baudrate won't change anything if systemd doesn't even see the device in the first place. It doesn't even get to the point of launching agetty.
By the way, Do I need to add some configuration to tiger executing something like 'mknod /dev/ttyPS0 c 248 0' for systemd or udev pls? If needed, where is the proper place to add this action pls?
No. The kernel automatically creates device nodes (as long as /dev has a "devtmpfs" mounted); udev only applies modes/symlinks. The problem here is that udev doesn't properly inform systemd about the new device.
>What does "udevadm info -a /dev/ttyPS0" output?
I can not get a console from ttyPS0, so I can not run "udevadm info -a /dev/ttyPS0" in the target(xilinx pynq) board.
Try booting with the 'rescue' option, this should directly create a root login prompt on the kernel console.
Alternatively, try creating a simple .service that runs this command, then you'll find its output in the journal or in the boot console (depending on what StandardOutput= you set).
Thanks all,
At 2020-09-22 20:34:15, "Andrei Borzenkov" <arvidjaar@xxxxxxxxx> wrote:
>On Tue, Sep 22, 2020 at 2:53 PM Mantas Mikulėnas <grawity@xxxxxxxxx> wrote:
>>
>> On Tue, Sep 22, 2020 at 1:46 PM Andrei Borzenkov <arvidjaar@xxxxxxxxx> wrote:
>>>
>>> On Tue, Sep 22, 2020 at 1:35 PM ZhouPeng <zhoupengwork01@xxxxxxx> wrote:
>>> >
>>> > Hi all,
>>> >
>>> > When I use Fedora image as rootfs on Xilinx PYNQ-Z2, I encountered the issue when use the /dev/ttyPS0.
>>> > I think the issue is because systemd and udev on fedora can didn't detect ttyPS0 properly. Do I need to install any other package or do some special configuration?
>>> >
>>> > **systemd version the issue has been seen with**
>>> > udevadm --version
>>> > 237
>>> > systemd-udev.riscv64 237-1.0.riscv64.fc28
>>> >
>>> >
>>> > **Unexpected behaviour you saw**
>>> > We can see ttyPS0 boots ok in the kernel boot period:
>>> > [ 0.180000] console [ttyPS0] enabledat MMIO 0xe0000000 (irq = 2, base_baud = 6250000) is a xuartps
>>> > [ 0.180000] console [ttyPS0] enabled
>>> >
>>> > But, when boot into systemd, it failed on dev ttyPS0:
>>> > [ TIME ] Timed out waiting for device dev-ttyPS0.device. // **here**
>>>
>>> systemd only monitors for devices with "sysemd" tag. Tags are assigned
>>> by udev rules. You should add rule to assign tag to ttyPS0. I have no
>>> idea what it is, but something like
>>>
>>> ACTION!="remove", KERNEL=="ttyPS0", TAG+="systemd"Mantas
>>>
>>> should do it. Whether this should go upstream depends on how common
>>> this device is.
>>
>>
>> Well yes, but that should have been already covered by the existing upstream rules:
>>
>> 99-systemd.rules:12:SUBSYSTEM=="tty", KERNEL=="tty[a-zA-Z]*|hvc*|xvc*|hvsi*|ttysclp*|sclp_line*|3270/tty[0-9]*", TAG+="systemd"
>>
>
>Are you sure ttyPS0 has the "tty" subsystem?
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