Re: Informations about mem and proc environment between bootloader and kernel

Hello Fabien,

you should download the U-boot sources from sourceforge.net. There is a=

README file there where you can read about porting U-boot.
The porting to a custom board of U-boot is easier when your cpu is incl=
ude,
like in your case (mpc8xx). Basically you have to create a new entry in=

board directory. There you have to insert the initialization code for y=
our
flash, sdram and other devices. You also have to make a file as the one=
s in
/include/configs/ with your configuration board.

It is essential to have correct environment variables when Linux takes =
the
control.
If you use the u-boot command "bootm" in order to boot Linux, the file
where U-Boot transfer the control to Linux is /common/cmd_bootm.c.

Moreover I would recommend you a book which explains many things regard=
ing
porting Linux (and U-boot):
Embedded Linux Primer: A practical, real-world  approach.

Cheers,

Ra=FAl Moreno



Ra=FAl Moreno Beltr=E1n
Telvent Energ=EDa, S. A.
Divisi=F3n de Tecnolog=EDa. Desarrollo Software
Tlfo: 954935670



"fabien boucher" [off-list ref]
"fabien boucher"
Enviado por:
linuxppc-embedded-bounces+raul.moreno=3Dtelvent.abengoa.com@ozlabs.org
13/09/2007 16:05
                                                                       =
                                                
 Para:   linuxppc-embedded@ozlabs.org                                  =
                                                
                                                                       =
                                                
 cc:                                                                   =
                                                
                                                                       =
                                                
 Asunto: Informations about mem and proc environment between bootloader=
 and     kernel                                 
                                                                       =
                                                





And I need some help for my project (I'm in internship) to port linux o=
n a
custom board.
This board has been developped by the company where i'm doing the inter=
ship
and it's
based on a MPC875 with RAM and Flash chips and several other devices.
Currently the board run with a BSP developped
by the company's developpers, the BSP launch Psos.
This BSP is able to decompress an image and load it in RAM.
I plan to use U-boot to be more able to boot a kernel but as it's not a=

common
board so it's not initialy supported by U-boot. So I have two choices f=
irst
use the BSP with some changes to adapt it for loading the Linux kernel =
or
using U-boot.
I'm looking for informations about the memory and processor environment=

needed by linux to
boot properly for evaluate whether the use of a customize BSP is the
easiest way against
the port of a new board under U-boot. So if someone know where i can fo=
und
those informations
concerning the step between where the boot program have control of the =
cpu
and where Linux
take control.

Thank you,
Fabien
_______________________________________________
Linuxppc-embedded mailing list
Linuxppc-embedded@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-embedded=