Creating a configuration for my custom MPC875 board

Creating a configuration for my custom MPC875 board

[Peter Asemann]

Some days ago I was told on this mailinglist I needed to create a custom 
configuration in order to get linux running on my custom hardware.

So I did as I was told and created an own <name>_defconfig and entries 
in the menu via editing arch/ppc/config.in and so on.

Well, every board seems to include it's custom header file from 
platforms/<NAME>.h in the include/asm/mpc8xx.h header file.
Now I'm curious if I also need to include something?

It seems there usually isn't much stuff in the <name>.h file, only an 
IMAP_ADDR define and the definition of struct bd_info.

Do I need this stuff - or how do I find out?

Best regards,

Peter Asemann

Re: Creating a configuration for my custom MPC875 board

[Bryan O'Donoghue]

Peter Asemann wrote:
> Some days ago I was told on this mailinglist I needed to create a custom 
> configuration in order to get linux running on my custom hardware.
> 
> So I did as I was told and created an own <name>_defconfig and entries 
> in the menu via editing arch/ppc/config.in and so on.
> 
> Well, every board seems to include it's custom header file from 
> platforms/<NAME>.h in the include/asm/mpc8xx.h header file.
> Now I'm curious if I also need to include something?
> 
> It seems there usually isn't much stuff in the <name>.h file, only an 
> IMAP_ADDR define and the definition of struct bd_info.
> 
> Do I need this stuff - or how do I find out?
> 
> Best regards,
> 
> Peter Asemann


You'll definately need to find out what _your_ IMAP_ADDR is, that is 
something which is almost certainly going to be unique to your own PCB.

Aside from that depending on what bootloader you are using, you may or 
may not have to do things to enumerate a bd structure.

In the case of Redboot, you would probably have to take the board 
descriptor given by redboot and parse it, else, with u-boot, I think you 
have _less_ maintenance on that front.

Do you have a working bootloader for your board, something that will try 
to execute a *image ? If you do, then getting Linux booting should be 
relatively trivial.

Bod

Re: Creating a configuration for my custom MPC875 board

[Wolfgang Denk]

In message <42079D4D.9090904@eircom.net> Bryan O'Donoghue wrote:
>
> You'll definately need to find out what _your_ IMAP_ADDR is, that is 
> something which is almost certainly going to be unique to your own PCB.

Actually the location of the IMMR area i just a part of the  system's
memory  map, which you just make up yourself - i. e. you can chose it
pretty freely, and in many cases you just copy  te  mapping  of  some
existing, similar board.

Of course you have to understand what you  are  doing,  but  this  is
always the case, isn't it?

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
To understand a program you must become  both  the  machine  and  the
program.