Help required to bring up kernel from U-Boot

Help required to bring up kernel from U-Boot

[batsayan.das]

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Hello,

I am using MPC8260ADS based customs board. I have configured the memory 
map in U-Boot as follows

SDRAM : 0x00000000  (size=128 MB)
FLASH   :  0x30000000 (size= 1MB)
SRAM : 0xFFF00000 (size 4MB)

There are also other components in the board, like  FRAMER , DSP, etc. I 
have not initialized the memory map of those components in U-Boot. 
I am able to get the U-Boot prompt when run by TRACE23.  I have build a 
default MPC8260ADS kernel, the only changes I have made is in the variable 
IMAP_ADDR , BCSR_ADDR in  arch/ppc/platforms/ads8260.h. I have put those 
values from the already running U-Boot code. 

Our TEXT_BASE=0xFFF00000
HRCW value= "0E A2 82 05" 

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?

My question is
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. 
2. Is the info passed from U-Boot is sufficient enough to make the kernel 
up?
3. If not, where should I concentrate in Linux tree?

Pls help.

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

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

[Wolfgang Denk]

In message <OFB8CF31AB.E132BC0B-ON652570D9.001789DD-652570D9.001A8A99@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@denx.de
CONSUMER NOTICE:  Because  of  the  "Uncertainty  Principle,"  It  Is
Impossible  for  the  Consumer  to  Find  Out  at  the Same Time Both
Precisely Where This Product Is and How Fast It Is Moving.

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

[batsayan.das]

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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@tcs.com
Website: http://www.tcs.com



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

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






In message 
<OFB8CF31AB.E132BC0B-ON652570D9.001789DD-652570D9.001A8A99@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@denx.de
CONSUMER NOTICE:  Because  of  the  "Uncertainty  Principle,"  It  Is
Impossible  for  the  Consumer  to  Find  Out  at  the Same Time Both
Precisely Where This Product Is and How Fast It Is Moving.

ForwardSourceID:NT000081B2 


Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information.   If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited.   If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments.  Thank you

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