[U-Boot-Users] Help required to bring up kernel from U-Boot

[batsayan.das at tcs.com]

1. Doing the changes in Linux tree suggested in 
http://www.denx.de/wiki/view/DULG/LinuxHangsAfterUncompressingKernel 
yields the same result. We already did those changes. 

2. Here is the procedure how I got the o/p of printk even if I do not get 
anything at console.

Run u-boot from Trace32
bootm <addr>  //  Now in our case Linux hangs after giving the o/p "## 
Transferring control to Linux (at address 00000000) ..."
stop u-boot //Do not hard reset the target
Again run U-Boot from Trace32
md <addrss of log_buf>  // search for "log_buf" in System.map in Linux 
tree. You will get this address.

Batsayan Das
Tata Consultancy Services Limited
Mailto: batsayan.das at tcs.com
Website: http://www.tcs.com



Wolfgang Denk <wd at denx.de> 
Sent by: wd at denx.de
12/16/2005 03:41 PM

To
batsayan.das at tcs.com
cc
u-boot-users at lists.sourceforge.net, linuxppc-embedded at ozlabs.org
Subject
Re: [U-Boot-Users] Help required to bring up kernel from U-Boot






In message 
<OFB8CF31AB.E132BC0B-ON652570D9.001789DD-652570D9.001A8A99 at tcs.com> you 
wrote:
>
> I copied uImage to location 0x04000000 and  the Load Address=0x00000000 
> and Entry point=0x00000000.  The bootm 0x04000000 gives the o/p 
> "Transferring Control to Linux" and then nothing comes. Where is the 
> wrong?

This is a FAQ. Please see http://www.denx.de/wiki/DULG/Faq

> 1. What are the minimum information Linux needs from U-Boot to come up 
> properly?  In the Linux source tree we have put some printk statement 
and 
> found that base address of SDRAM, size, etc are passed correctly to 
Linux 
> by U-Boot. 

Be careful with printk() at inappropieate places (i.e. too early).

But tell me - how where you  able  to  see  anthing  with  printk  if
"nothing comes" as you write above ???

> 2. Is the info passed from U-Boot is sufficient enough to make the 
kernel 
> up?

Yes, of course. It works on thousands of systems.

> 3. If not, where should I concentrate in Linux tree?

On your changes.

And please keep this off the U-Boot list. It is off topic here.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
CONSUMER NOTICE:  Because  of  the  "Uncertainty  Principle,"  It  Is
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