[U-Boot] UBoot NFS timeout

[Ben Warren]

Hi Christopher,

Please don't top-post.

Christopher McNamara wrote:
> It is a microblaze on a Xilinx Virtex 5. Not sure what the MAC is
> unless it is built into the VITESSE vsc8211 PHY...
>
>   
I've never used this configuration, but assume it's using some kind of 
Xilinx-provided soft MAC.  It probably doesn't matter much anyway.
> The only code on the machine at this time is the UBoot 1.2 image, no
> linux kernel.
>
> I was led to believe by the documentation that I could boot the whole
> image via nfs, I am faced with a situation where tftp is not allowed
> so I was thinking this could be the alternative. (I have a working
> linux image, I am just looking for an alternative route to get it to
> the board.)
>
> My command is
> nfs 0x80000000 xxx.xxx.50.21:/root/Desktop/susenfs/bootme4linux.bin
>
> For what you are saying with the rsize= parameter I wouldn't use this
> command but rather change the bootargs parameter like this...
>
> setenv bootargs root=?? rw
> nfsroot=177.174.50.21:/root/Desktop/susenfs/bootme4linux.bin,rsize=512,wsize=512,nolock
> ip=177.174.50.151
>
> and then do a
>
> loadb
>
> Without the kernel there what would my root= parameter be?
>
>   
No, I don't think this is what you want to do.  You want to use the 
'nfs' command.  I confess I've never used it so can only help by code 
inspection.  It appears that U-boot sets the read size to 1024, which is 
much smaller than the 4k or 8k block size that you'd run into using a 
regular NFS mount.

Anyway, something else to try is to throttle your network speed by 
forcing your PHY to 10/half.  You should be able to do that with the 
miiphy commands.  Your MAC will surely be able to keep up with it and 
this will tell you if the problem is really due to throughput.  The 
downside is that things will seem reeaaallllyy slllloooowwww.

regards,
Ben