Re: [U-Boot] Is it possible to boot the U-boot from the another U-boot from the flash area

2012-06-29 Thread Schneider, Kolja
Dear Ishwar Saunshi,
 
  I have gone through the FAQ section, this FAQ only talks about the
  condition where the other Uboot is in RAM but what I am thinking is to
 boot
  the Uboot from the flash location by another running Uboot.
 
 This doesn't make any difference.  Read more carefully, and read to
 the end.  Pay special attention to the part here:
 
   U-Boot expects to see a virgin CPU, i. e. the CPU state must
   match what you see if the processor starts executing the first
   instructions when it comes out of reset. If you want to start
   U-Boot from another boot loader, you must disable a lot of
   code ...
 

This is really highly CPU-dependent. We are using something like that to 
implement a fallback u-boot image in case someone manages to kill
the standard image, it was quite easy to do for e.g. mpc512x, but quite some 
coding effort for mpc85XX. The corresponding code always looks 
slightly insane. If you feel like diving in deep into the innards of
your CPU, go for it. If you don't really need it, skip it.

:-) Kolja

 
 Best regards,
 
 Wolfgang Denk
 
 --
 DENX Software Engineering GmbH, MD: Wolfgang Denk  Detlev Zundel
 HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
 Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de
 You don't have to stay up nights to succeed; you have to  stay  awake
 days.
 ___
 U-Boot mailing list
 U-Boot@lists.denx.de
 http://lists.denx.de/mailman/listinfo/u-boot
___
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot


Re: [U-Boot] Is it possible to boot the U-boot from the another U-boot from the flash area

2012-06-28 Thread Ishwar Saunshi
Thanks Wolfgang,

I have gone through the FAQ section, this FAQ only talks about the
condition where the other Uboot is in RAM but what I am thinking is to boot
the Uboot from the flash location by another running Uboot.

for example if my board flash starts from 0xC000_ to 0xCFFF_ and
the first Uboot-1 is programmed @ 0xC800_ and second Uboot-2 is
programmed @0xC500_ on reset Uboot-1 starts from flash and load it self
to RAM and boots up and from there is it possible to boot Uboot-2 by using *
go* cmd or in any other way.


Regards,
ISHWAR


On Wed, Jun 27, 2012 at 7:19 PM, Wolfgang Denk w...@denx.de wrote:

 Dear Ishwar Saunshi,

 In message 
 cakd3hysshg8+xnx1yqnvddlyqupgajc-lmg1qz32cy5ebm6...@mail.gmail.com you
 wrote:
 
  I am really curiuos to see if U-boot can boot another version or another
  Uboot burnt in flash ?
  Its like having 2 images of U-boot which can boot each other if it is
  possible can any one of you hint me how I can achive this. I tried to
  relocate the Uboot and burned on to the flash in 2 different loacation
  however when I try to do go U-boot effective address it ends up in
 TLB
  error in early stage of flash execution.

 In general, this is not possible.  This topic is covered in the FAQ
 here:

 http://www.denx.de/wiki/view/DULG/CanUBootBeConfiguredSuchThatItCanBeStartedInRAM


 Best regards,

 Wolfgang Denk

 --
 DENX Software Engineering GmbH, MD: Wolfgang Denk  Detlev Zundel
 HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
 Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de
 Out of register space (ugh)
 - vi

___
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot


[U-Boot] Is it possible to boot the U-boot from the another U-boot from the flash area

2012-06-27 Thread Ishwar Saunshi
Hi All,

I am really curiuos to see if U-boot can boot another version or another
Uboot burnt in flash ?
Its like having 2 images of U-boot which can boot each other if it is
possible can any one of you hint me how I can achive this. I tried to
relocate the Uboot and burned on to the flash in 2 different loacation
however when I try to do go U-boot effective address it ends up in TLB
error in early stage of flash execution.


Thanks for the Help.
Ish
___
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot


Re: [U-Boot] Is it possible to boot the U-boot from the another U-boot from the flash area

2012-06-27 Thread Wolfgang Denk
Dear Ishwar Saunshi,

In message cakd3hysshg8+xnx1yqnvddlyqupgajc-lmg1qz32cy5ebm6...@mail.gmail.com 
you wrote:
 
 I am really curiuos to see if U-boot can boot another version or another
 Uboot burnt in flash ?
 Its like having 2 images of U-boot which can boot each other if it is
 possible can any one of you hint me how I can achive this. I tried to
 relocate the Uboot and burned on to the flash in 2 different loacation
 however when I try to do go U-boot effective address it ends up in TLB
 error in early stage of flash execution.

In general, this is not possible.  This topic is covered in the FAQ
here:
http://www.denx.de/wiki/view/DULG/CanUBootBeConfiguredSuchThatItCanBeStartedInRAM


Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH, MD: Wolfgang Denk  Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de
Out of register space (ugh)
- vi
___
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot