Hi,

I am using a linux kernel 2.6.36 using mips architecture. I have succesfully booted the machine through Flash memory, but it is not booting through nfs. It is getting stuck at the stage where the image starts loading. In short the vmlinux.img file is being copied properly to nfsroot but the image is not loading.

It sound like you may not understand the concept of an NFS root filesystem. By the time an NFS root filesystem (or any root filesystem, for that matter) is required, the kernel must already have been loaded into memory, and invoked. Putting the kernel image on the NFS root filesystem will contribute nothing to the boot.
Perhaps you should give us the details of what you are trying to accomplish, and what you have tried so far.
--- rod.

U-Boot 1.3.3 (Jan 5 2011 - 17:24:10)

Board: DbAu1250
CPU: Au1250, id: 0x02, rev: 0x02
DRAM: 128 MB
Flash: 128 MB
copy env 87f80008 bfc80000 65536
In: serial
Out: serial
Err: serial
Running on battery, insuring vbat > 125...
VBAT is 167, OK
ethaddr=00:0E:BD:05:ff:e5
Hit Ctrl-C to stop autoboot: 0
## Executing script at bfca0000
Protected 4 sectors

## Checking Image at bfcc0000 ...
Legacy image found
Image Name: dev start script
Created: 2009-12-14 13:55:38 UTC
Image Type: PowerPC Linux Script (uncompressed)
Data Size: 842 Bytes = 0.8 kB
Load Address: 00000000
Entry Point: 00000000
Contents:
Image 0: 834 Bytes = 0.8 kB
Verifying Checksum ... OK
halfword at 0xa2800000 (0xf3cf) != halfword at 0xb600000e (0xffff)
Total of 0 halfwords were the same
not pressing N
halfword at 0xa2800000 (0xd7d7) != halfword at 0xb600000e (0xffff)
Total of 0 halfwords were the same
not pressing F
Total of 1 halfword were the same
NFSROOT mode selected
## Executing script at bfcc0000
i am the nfsrootScript!!!
lan9118: eth_halt
DRIVER_VERSION : 100, DATECODE : 092706
LAN9x18 (0x115a0000) detected.
PWR_MGMT 1
PWR_MGMT 1
start Auto negotiation... (take ~2sec)
Auto negotiation complete, 100BaseTX, full duplex
File transfer via NFS from server 172.31.77.137; our IP address is 172.31.77.149
Filename '/home/csc/tmp/nfsroot/vmlinux.img'.
Load address: 0x81000000
Loading: #

Booting through nfs hangs at this stage

Okay, so both the bootloader and kernel are using NFS? The bootloader to load the kernel and the kernel to provide a root filesystem? I have never used U-Boot, but from the messages, it looks like it is trying to load the kernel from an NFS server. Is there a working NFS server at the specified address? When you boot to U-Boot, do you see any messages in the NFS server log files about the attempted connection? Can you mount the exported filesystem from some other host (like a fully booted Linux host)?

It isn't yet discernible that the kernel will try to mount an NFS root filesystem, but if it needs to, it will have to have NFS root capability built in to it, and may require kernel arguments to specify the nature of the NFS root filesystem. I would have expected the bootloader to display such arguments, but I don't see anything except the message 'NFSROOT mode selected'. Just from the context, this seems to apply only to the bootloader itself.

So far, this seems to be an issue of U-Boot being able to mount an NFS share. Focus on making sure the NFS server is working.

--- rod.

NFS is loaded at that address. The device boots properly through NFS when using kernel 2.6.33.2. I would like to know if I need to make any change in settings in NFS or configuration of 2.6.36 or any other settings to boot it using kernel 2.6.36. I have already applied changes required to my driver files,interrupts etc.