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seen Dec 11 '13 at 16:12

Mar
4
awarded  Commentator
Sep
17
comment A Reboot() command with failover
Sorry, I should have specified that I'm running Busybox. No run levels. But changing the run level, and calling the kill scripts just calls reboot command in the end anyway.
Sep
17
revised A Reboot() command with failover
added 95 characters in body
Sep
17
asked A Reboot() command with failover
Jul
11
awarded  Teacher
Jul
9
comment can't initialise/detect 16550A UART at unusual io port address
Just to add. Linux detects my COM9 as ttyS4 in dmesg. e.g. serial8250.11: ttyS4 at I/O 0x10 (irq = 9) is a 16550A. udev/mdev will automatically create a node for it in /dev. So AFAIK the kernel knows about this node, but it doesn't seem to work as a tty device. e.g. # picocom -b 9600 /dev/ttyS4 ... FATAL: failed to add device /dev/ttyS4: Filedes is not a tty. Possibly there's a problem in my driver, but it all looks fairly straight forward how I am supposed to add a basic 8250 compatible device.
Jul
9
comment can't initialise/detect 16550A UART at unusual io port address
I've since got the UART part working. Now I'm working on getting the Linux part working. My driver enables the correct settings in the Southbridge now, but Linux doesn't associate the /dev/ttyS4 with a tty. e.g. # stty -F /dev/ttyS4 9600 stty: /dev/ttyS4: Input/output error
Jul
9
answered can't initialise/detect 16550A UART at unusual io port address
Jul
9
comment can't initialise/detect 16550A UART at unusual io port address
An attempt to do a setserial autoconfig fails with: ttyS4: autoconf (0x0010, 0x (null)): IER test failed (0f, 0f) type=16550A ttyS4: LSR safety check engaged! ttyS4: LSR safety check engaged! Which is what the kernel fails with as well.
Jul
9
comment can't initialise/detect 16550A UART at unusual io port address
Nope, setserial doesn't work. The kernel still does the same autoconfig and scanning as setserial does. # setserial /dev/ttyS4 port 0x10 irq 9 uart 165 50A ttyS4: LSR safety check engaged!
Jul
6
asked can't initialise/detect 16550A UART at unusual io port address
Jul
4
revised Does the kernel delete entries in /dev on an initramfs?
Emphasised that my system is a custom system.
Jul
4
comment Does the kernel delete entries in /dev on an initramfs?
Yes, it's very odd. The exact same system mounted as NFS works correctly. But when I make an initramfs from the same files, it does something differnt. inittab was clean, it simply does ::sysinit:/etc/init.d/rcS. Oh, well, I'm going to side step this problem by using mdev -s to create /dev at boot and use a minimal /dev with just console and null devices. Thanks for the help.
Jul
3
comment Does the kernel delete entries in /dev on an initramfs?
The only thing I can think of checking might be the /etc/inittab file which is the only user customisable script that gets called before /etc/init.d/rcS AFAIK it only calls /etc/init.d/rcS but I did have some other mount scripts in there earlier, I may have left some cruft that I have forgotten about. I will have to check when I get back in to work tomorrow.
Jul
3
comment Does the kernel delete entries in /dev on an initramfs?
The thing is 100% custom. There is no remnants of anything. The boot scripts are all my own doing. My /etc/init.d/rcS simply does this: #!/bin/sh ls /dev ... and I can see that /dev/hda1 is missing. There is nothing else running before I list the /dev directory.
Jul
3
revised Does the kernel delete entries in /dev on an initramfs?
added 74 characters in body
Jul
3
revised Does the kernel delete entries in /dev on an initramfs?
added 128 characters in body
Jul
3
comment Does the kernel delete entries in /dev on an initramfs?
This is a custom distribution for a fixed embedded target so it only needs a static /dev and there is no udev. I only run mdev as the hotplug agent because I handle USB Flash drives. The directory listing from the target was performed right after init was executed by the kernel. No other applications or daemons are running at this time.
Jul
3
awarded  Student
Jul
3
awarded  Editor