Reset problem at the time of kernel booting in linux via TFTP

[lpcware]

Content originally posted in LPCWare by MOHAMMAD BIYABANI on Tue Feb 05 05:10:51 MST 2013
Hi, Now i am working on LPC3250 micro controller and in my board SDRAM(512MB) and NAND FLASH(32MB) are interfaced.I was dumped the U-BOOT in NAND FLASH.I tried to boot the kernel in linux ubuntu via TFTP.But, after kernel booted the kernel booting process starts once again(that means reset automatically). I thought that may be the problem in SDRAM and NAND FLASH initialazation or RESET circuit.So,I have checked them but no problem in that. I am not able to recognize what is the problem is actually.can anyone help me please.I attached the SNAPSHOT of kernel booting process.May be that helpful for you people to find out the problem......plea

[lpcware]

Content originally posted in LPCWare by MOHAMMAD BIYABANI on Thu Feb 07 00:01:39 MST 2013
i disable the watchdog timer in kernel hacking section then also i faced same problem(reset problem). should we have to enable or disable some other options which are not set default for kernel booting?
what are settings are used for SDRAM initialization?if you know please post... 

[lpcware]

Content originally posted in LPCWare by wellsk on Wed Feb 06 10:02:00 MST 2013
If you didn't specifically add the watchdog support in u-boot, it's probably not there.

>CONFIG_DEBUG_ALL option in kernel or u-boot
This is a kernel build option in the 'kernel hacking' section. It enables early and low-level kernel messages via the UART port before the console starts. You have to rebuild the kernel to enable this option, but first you need to configure the kernel first.

Another thing to look at are your u-boot environment variables via the u-boot command printenv. You can dump them here.

[lpcware]

Content originally posted in LPCWare by MOHAMMAD BIYABANI on Wed Feb 06 05:31:34 MST 2013
Thanks for reply...I disabled the watchdog timer support in device drivers in kernel but got the same problem...There is short delay between the "booting the kernel" message and the restart of u-boot...I have doubt you told that disable the watchdog timer in U-boot,do you have any idea about how do disable the watchdog timer in U-boot and where i find this CONFIG_DEBUG_ALL option in kernel or u-boot? ...I am new to linux and lpc3250 board...I dont know how to make that...please reply me if u know...i am waiting for your reply...thanks once again....

[lpcware]

Content originally posted in LPCWare by wellsk on Tue Feb 05 09:19:00 MST 2013
this could be anything, but I'd start by enabling low level DEBUG messages for the kernel first and hope for more boot information..I believe the options was CONFIG_DEBUG_LL

Are you using the watchdog timer in u-boot or the kernel? Make sure it's disabled

is there a long or short delay between the "booting the kernel" message and the restart of u-boot?