I think Mr. Fouse is wright. As the ppp logfile clearly states, the / or specifically the /dev is write protected. It may be mounted as read-only file system to increase the flash life cycle. As it isknown that flash memories has life time related with the number of erase/write operations. However, Linux needs a read/write file system especially, /var, /dev and /tmp directories. I think you can solve this problem by creating a RAM disk and copying the contents of your original /dev directory to the created RAM disk. You can do this stuff in one of initialization scripts before the pppd acesses it.
Lets say you have a mount point at /mnt/ram you create the Ram disk by mke2fs -m 0 /dev/ram0 -i 1024 1000 mount -n /dev/ram0 /mnt/ram cp -a /dev/* /mnt/ram umount /dev/ram0 mount -n /dev/ram0 /dev You can add this to an initialization script. You may use minix or other filesystem to open the ramdisk. And you may change the size (1000) By this way you get a read/write capable ramdisk acting as your /dev and any process that needs to write on /dev can now write on the mounted ramdisk, instead of your read-only flash. In fact it may be useful for you to look at the mail archieve related with flashdisk usage and readonly filesystem tips. Iskender Yigitel On Mon, 3 Dec 2001, George Fouse wrote: > Hello, > In your embedded linux system, is '/' (or more specifically, '/dev') > ram-based or mounted 'read-only' from flash, etc? > Your ppp logfile (I think) suggests this- > "Couldn't restrict write permissions to /dev/ttyS0: Read-only file > system" > Normally, the device permissions/ownership will get changed (and also > with login). > ...just a thought. > George > > joost wrote: > > > > Hi All, > > I try to login at a modem connected to an embedded linux system, but I don't > > get it to work. I tried almost everything. I hope someone knows what is going > > wrong. The system I use is the developerboard lx with an ETRAX 100 LX chip > > from Axis. I installed ppp and mgetty on the devboard. Mgetty is a getty > > specially for modems. I also tried with the getty from tinylogin and with > > agetty, but those gave the same problems. After the modems have connected I > > can see in the ppp logfile (of the client): > > > > send [LCP ConfReq id=0x1> <pcomp> <accomp>] > > last message repeated 9 times > > LCP: timeout sending Conf > > Connection terminated > > > > And then the connection ends. > > In the other ppp logfile I get the messageges: > > > > pppd 2.4.1 started by root, uid 0 > > Couldn't restrict write permissions to /dev/ttyS0: Read-only file system > > > > I tried to set up a ppp connection in the other way (devboard as client, > > normal pc as server) and this worked without any problems. There was a > > little difference in the 2 ppp logfiles from the server: > > > > The logfile from the working ppp connection (devboard as client): > > ..... > > waiting for line to clear (VTIME), read: > > looking for utmp entry... (my PID: 23951) > > utmp + wtmp entry made > > tio_set_flow_control ( HARD ) > > getlogname (AUTOPPP), read:~[ff]}#[c0]! > > input finished with '\r', setting ICRNL ONLCR > > tio_get_rs232_lines: status: RTS CTS DSR DTR DCD > > ..... > > > > The logfile from the not working ppp connection (devboard as server): > > ..... > > waiting for line to clear (VTIME), read: > > looking for utmp entry... (my PID: 52) > > tio_set_flow_control ( HARD ) > > getlogname (AUTOPPP), read:~[ff]}#[c0]! > > input finished with '\r', setting ICRNL ONLCR > > tio_get_rs232_lines: status: RTS CTS DSR DTR DCD RI > > ..... > > > > A difference is that at the last one there is no utmp and wtmp entry made. I > > checked on the devboard, and there is a utmp file, but no wtmp file. > > There is also a difference in the status of the 232_lines, so I tested the > > serial line with a test program installed on the devboard: > > > > 'hwtestserial -d /dev/ttyS0 -loopback 4' > > and I got the message: > > 'test failed: CD and RI high when expected to be low (RTS high, DTR low)' > > this is not good, is it? > > > > I also tried to dialin at the devboard without ppp, but then when typing a > > username after the loginprompt nothing happens. > > > > Does anyone know what might be going wrong and what to do about it? > > Your response would be greatly appreciated, > > Joost Reus > ------------------------------ > George Fouse, > President > Quantum Technology Associates > System and Network Services > ------------------------------ -- To unsubscribe from this list, send a message to [EMAIL PROTECTED] with the command "unsubscribe linux-embedded" in the message body. For more information, see <http://waste.org/mail/linux-embedded>.
