I'll answer one of my questions myself, apparently if you :
edit /etc/sysctl.conf
add "kernel.panic = 10"

it will reboot 10 seconds after a kernel panic.

If any one could help me with the other questions that would great!

Thanks for your reply

Hi,

I have a Sheeva using a USB 3g modem (PPP) and USB to 485 (FT232BM) board to talk to a network of sensors.

Using the 2.6.33 kernel (From cbxbiker61) after 2-3 days the sheeva will hang and not accept serial/network input

Today I had the serial attached and I managed to catch the Oops, I'm new to this, is there a way I can make the Sheeva reboot on an oops? is there somewhere I should report this?

Or should I downgrade the kernel/ compile my own?

root@ubuntu:~# Unable to handle kernel NULL pointer dereference at virtual address 000000e8
pgd = c0004000
[000000e8] *pgd=00000000
Internal error: Oops: 17 [#1] PREEMPT
last sysfs file: /sys/module/ppp_generic/initstate
Modules linked in: ppp_async ppp_generic slhc dm_crypt dm_mod sr_mod ftdi_sio option cdrom usbserial mv_cesa
CPU: 0    Not tainted  (2.6.33 #2)
PC is at tty_buffer_request_room+0x20/0x148
LR is at tty_buffer_request_room+0x20/0x148
pc : [<c025390c>]    lr : [<c025390c>]    psr: 80000093
sp : df841d78  ip : c0410580  fp : df1c0100
r10: 20000093  r9 : ffc00480  r8 : dd8be980
r7 : df1e7400  r6 : 0000000e  r5 : 00000000  r4 : 00000000
r3 : df840000  r2 : 00000000  r1 : 00010003  r0 : 00000004
Flags: Nzcv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
Control: 0005397f  Table: 1d880000  DAC: 00000017
Process events/0 (pid: 5, stack limit = 0xdf840270)
Stack: (0xdf841d78 to 0xdf842000)
1d60:                                                       00000000 dd8be400
1d80: 00000000 df2fc000 df1e7400 dd8be980 df98ccf4 bf0261d8 dd8be400 df98cc00
1da0: dd8be400 dd8be400 00000000 df98cc00 0ff28d00 c02df2c0 dd8be400 00000000
1dc0: df98cc00 c02ee4f0 ffc018a0 ffc01900 ffffff8d c02ee5c0 00000001 00000001
1de0: df1c010c 00000003 ffc01398 ffc019c0 00000021 df1c0100 df98ccf4 00000000
1e00: 0000c0a9 00010039 00000000 00000000 df841f0c c02ef9f0 df98ccf4 df98cc00
1e20: 00000021 c02f248c c0434df0 df98cc00 60000013 df057740 00000013 00000000
1e40: 00000000 00000000 df841f0c c02decec c0579480 df057740 df840000 c007545c
1e60: c0551f68 00000013 df057740 00000003 00000002 df840000 00000000 c00775d8
1e80: 00000013 00000000 0000000c c002c06c 00000013 ffffffff fee20200 c0406b68
1ea0: 00000001 00000000 00000001 00000013 df832c00 df840000 df832d84 c02e09e0
1ec0: df8ecf00 00000000 00000000 df841f0c c054f138 df841ee8 c0039058 c04048b8
1ee0: 00000013 ffffffff 00000001 dd8be580 df841f14 df832c00 00000000 df840000
1f00: 00000000 00000000 00000001 c02e09e0 00000001 00000000 df832c00 c005c294
1f20: c056bfd4 c056bfd4 df8669c0 00000004 df1fee40 bf025a90 df1e7404 df1e7430
1f40: 40000013 bf00702c bf00af2c c0253dd4 dd875108 dd875000 40000013 c024c1d4
1f60: 60000093 00000000 df800420 df840000 df800420 df800428 c024be1c dd87510c
1f80: 00000000 dd875108 df832c00 c00584e8 df832c00 00000000 df832c00 c005c294
1fa0: df841fa0 df841fa0 00000002 df835f48 df841fd4 c0058300 df800420 00000000
1fc0: 00000000 00000000 00000000 c005be6c 00000000 00000000 df841fd8 df841fd8
1fe0: 00000000 00000000 00000000 00000000 00000000 c002d42c 0000ffff 0000ffff
[<c025390c>] (tty_buffer_request_room+0x20/0x148) from [<bf0261d8>] (option_indat_callback+0x94/0x148 [option])
[<bf0261d8>] (option_indat_callback+0x94/0x148 [option]) from [<c02df2c0>] (usb_hcd_giveback_urb+0x70/0xbc)
[<c02df2c0>] (usb_hcd_giveback_urb+0x70/0xbc) from [<c02ee4f0>] (ehci_urb_done+0xa8/0xb4)
[<c02ee4f0>] (ehci_urb_done+0xa8/0xb4) from [<c02ee5c0>] (qh_completions+0xc4/0x42c)
[<c02ee5c0>] (qh_completions+0xc4/0x42c) from [<c02ef9f0>] (end_unlink_async+0x5c/0xec)
[<c02ef9f0>] (end_unlink_async+0x5c/0xec) from [<c02f248c>] (ehci_irq+0x90/0x1f0)
[<c02f248c>] (ehci_irq+0x90/0x1f0) from [<c02decec>] (usb_hcd_irq+0x3c/0x98)
[<c02decec>] (usb_hcd_irq+0x3c/0x98) from [<c007545c>] (handle_IRQ_event+0xa8/0x1ec)
[<c007545c>] (handle_IRQ_event+0xa8/0x1ec) from [<c00775d8>] (handle_level_irq+0xcc/0x15c)
[<c00775d8>] (handle_level_irq+0xcc/0x15c) from [<c002c06c>] (asm_do_IRQ+0x6c/0x8c)
[<c002c06c>] (asm_do_IRQ+0x6c/0x8c) from [<c0406b68>] (__irq_svc+0x48/0xa8)
Exception stack(0xdf841ea0 to 0xdf841ee8)
1ea0: 00000001 00000000 00000001 00000013 df832c00 df840000 df832d84 c02e09e0
1ec0: df8ecf00 00000000 00000000 df841f0c c054f138 df841ee8 c0039058 c04048b8
1ee0: 00000013 ffffffff
[<c0406b68>] (__irq_svc+0x48/0xa8) from [<c04048b8>] (schedule+0x20c/0x3c8)
[<c04048b8>] (schedule+0x20c/0x3c8) from [<c02e09e0>] (usb_kill_urb+0xb8/0xf4)
[<c02e09e0>] (usb_kill_urb+0xb8/0xf4) from [<bf025a90>] (option_close+0xa0/0xf0 [option])
[<bf025a90>] (option_close+0xa0/0xf0 [option]) from [<bf00702c>] (serial_down+0x2c/0x30 [usbserial])
[<bf00702c>] (serial_down+0x2c/0x30 [usbserial]) from [<c0253dd4>] (tty_port_shutdown+0x58/0x64)
[<c0253dd4>] (tty_port_shutdown+0x58/0x64) from [<c024c1d4>] (do_tty_hangup+0x3b8/0x430)
[<c024c1d4>] (do_tty_hangup+0x3b8/0x430) from [<c00584e8>] (worker_thread+0x1e8/0x2a8)
[<c00584e8>] (worker_thread+0x1e8/0x2a8) from [<c005be6c>] (kthread+0x78/0x80)
[<c005be6c>] (kthread+0x78/0x80) from [<c002d42c>] (kernel_thread_exit+0x0/0x8)
Code: e38a3080 e121f003 e3a00001 eb06d46b (e59450e8)
---[ end trace 35feb3bc573ddc7e ]---
Kernel panic - not syncing: Fatal exception in interrupt
[<c0031804>] (unwind_backtrace+0x0/0xdc) from [<c0404494>] (panic+0x48/0x124)
[<c0404494>] (panic+0x48/0x124) from [<c002ffcc>] (die+0x180/0x1ac)
[<c002ffcc>] (die+0x180/0x1ac) from [<c0032444>] (__do_kernel_fault+0x64/0x74)
[<c0032444>] (__do_kernel_fault+0x64/0x74) from [<c0408968>] (do_page_fault+0x22c/0x244)
[<c0408968>] (do_page_fault+0x22c/0x244) from [<c002c2f8>] (do_DataAbort+0x34/0x94)
[<c002c2f8>] (do_DataAbort+0x34/0x94) from [<c0406b0c>] (__dabt_svc+0x4c/0x60)
Exception stack(0xdf841d30 to 0xdf841d78)
1d20:                                     00000004 00010003 00000000 df840000
1d40: 00000000 00000000 0000000e df1e7400 dd8be980 ffc00480 20000093 df1c0100
1d60: c0410580 df841d78 c025390c c025390c 80000093 ffffffff
[<c0406b0c>] (__dabt_svc+0x4c/0x60) from [<c025390c>] (tty_buffer_request_room+0x20/0x148)
[<c025390c>] (tty_buffer_request_room+0x20/0x148) from [<bf0261d8>] (option_indat_callback+0x94/0x148 [option])
[<bf0261d8>] (option_indat_callback+0x94/0x148 [option]) from [<c02df2c0>] (usb_hcd_giveback_urb+0x70/0xbc)
[<c02df2c0>] (usb_hcd_giveback_urb+0x70/0xbc) from [<c02ee4f0>] (ehci_urb_done+0xa8/0xb4)
[<c02ee4f0>] (ehci_urb_done+0xa8/0xb4) from [<c02ee5c0>] (qh_completions+0xc4/0x42c)
[<c02ee5c0>] (qh_completions+0xc4/0x42c) from [<c02ef9f0>] (end_unlink_async+0x5c/0xec)
[<c02ef9f0>] (end_unlink_async+0x5c/0xec) from [<c02f248c>] (ehci_irq+0x90/0x1f0)
[<c02f248c>] (ehci_irq+0x90/0x1f0) from [<c02decec>] (usb_hcd_irq+0x3c/0x98)
[<c02decec>] (usb_hcd_irq+0x3c/0x98) from [<c007545c>] (handle_IRQ_event+0xa8/0x1ec)
[<c007545c>] (handle_IRQ_event+0xa8/0x1ec) from [<c00775d8>] (handle_level_irq+0xcc/0x15c)
[<c00775d8>] (handle_level_irq+0xcc/0x15c) from [<c002c06c>] (asm_do_IRQ+0x6c/0x8c)
[<c002c06c>] (asm_do_IRQ+0x6c/0x8c) from [<c0406b68>] (__irq_svc+0x48/0xa8)
Exception stack(0xdf841ea0 to 0xdf841ee8)
1ea0: 00000001 00000000 00000001 00000013 df832c00 df840000 df832d84 c02e09e0
1ec0: df8ecf00 00000000 00000000 df841f0c c054f138 df841ee8 c0039058 c04048b8
1ee0: 00000013 ffffffff
[<c0406b68>] (__irq_svc+0x48/0xa8) from [<c04048b8>] (schedule+0x20c/0x3c8)
[<c04048b8>] (schedule+0x20c/0x3c8) from [<c02e09e0>] (usb_kill_urb+0xb8/0xf4)
[<c02e09e0>] (usb_kill_urb+0xb8/0xf4) from [<bf025a90>] (option_close+0xa0/0xf0 [option])
[<bf025a90>] (option_close+0xa0/0xf0 [option]) from [<bf00702c>] (serial_down+0x2c/0x30 [usbserial])
[<bf00702c>] (serial_down+0x2c/0x30 [usbserial]) from [<c0253dd4>] (tty_port_shutdown+0x58/0x64)
[<c0253dd4>] (tty_port_shutdown+0x58/0x64) from [<c024c1d4>] (do_tty_hangup+0x3b8/0x430)
[<c024c1d4>] (do_tty_hangup+0x3b8/0x430) from [<c00584e8>] (worker_thread+0x1e8/0x2a8)
[<c00584e8>] (worker_thread+0x1e8/0x2a8) from [<c005be6c>] (kthread+0x78/0x80)
[<c005be6c>] (kthread+0x78/0x80) from [<c002d42c>] (kernel_thread_exit+0x0/0x8)

Hi,

I need to execute a long processes from cron, currently I get cron to execute a bash script using the & operator to run it as a background process, from this bash script I execute my application again using the & to background the process, but when I look at the ps list I see [sh] <defunct>, [cron] <defunct>. as if cron is waiting around for my application to end?

should I be worried about defunct processes? is there a better way to get cron to kick of an application and not wait for it to end?

Thanks in advance.

Our projects are very similar, mine also uses a HDSPA usb modem to upload data, another tip, I had to update the kernel to add in PPP support so I could dial the modem, with out PPP support in the kernel I could not get a connection.

Im not sure I can help you with Java, it's not a language I have used with Linux. I quick google suggests you should be using the javax.comm api : http://java.sun.com/products/javacomm/

This page seems to have an example : http://www.captain.at/howto-java-serial-port-javax-comm-rxtx.php

Just noticed you have said in one of your posts you can see a "/dev/ttyUSB0" that means linux has done its stuff and you have a serial port to write to.

Hi SonicBoom,

I am actually doing exactly the same thing as you, I am using a sheeva with a USB to 485 FTDI232BL

Bus 001 Device 005: ID 0403:6001 Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC

I used the installer to set up ubuntu on an SD card, did an apt-get update/upgrade and then installed an up to date kernel ( Currently using Linux ubuntu 2.6.33)

When you attach the USB 485 it will appear in /dev as ttyUSBx (Where x is the next availible number).
I use a udev rule filter to symlink the /dev/ttyUSBx to /dev/usbserial so my C application can check and use /dev/usbserial instead of trying to find out which ttyUSBx is the 485 device

You can then treat it like a normal serial port, my USB to 485 automatically does the direction line switching not sure that's a function of the chip or my board so be aware of that.

Installing a new kernal was easy, I just did :
wget http://sheeva.with-linux.com/sheeva/README-2.6.33
chmod 777 README-2.6.33
. README-2.6.33 --nandkernel

That downloads a script, makes it executable then runs it tell the script we want to flash the kernal in Nand.

Hi,

I had an issue with dialing a 3G modem with pppd and getting the same log saying the kernel lacked PPP filtering support, so I asked in this thread :
http://plugcomputer.org/plugforum/index.php?topic=1372.0

And cbxbiker61 has re-compiled his kernel to include ppp filtering for us!

Carl.

  Your a star thanks!

Hi,

Im trying to dial a 3G USB modem attached to the sheeva, starting PPPd i see this :

"kernel does not support PPP filtering"

before the modem hangs up, So i guess I need ppp_filter support in the kernel too, if possible.

Thanks in advance!