[U-Boot-Users] bd_info vs. global_data

Wolfgang Denk wd at denx.de
Fri Nov 10 15:33:08 CET 2006

In message <4553E0C4.4010207 at freescale.com> you wrote:
> Is the bd located immediately after the gd in memory?

No, not at all. Actually we start with the gd, and space fopr the  bd
becomes only available after relocation to RAM.

> How about a rule that any function can write to bd_info (to initialize its 
> contents), but only the do_bootm_xxx functions can read from it, and only to 
> prepare it for passing to Linux.  This would eliminate code like this:
> #define OF_TBCLK		(bd->bi_busfreq / 4)

I don't see how such a rule would actually prevent such code...

> and hopefully stuff like this:

No, this is perfectly reasonable and necessary.

> In this case, I don't understand the clocks_in_mhz environment variable.  Is 


> this something that we really want to be run-time configurable?

Yes, of course we de. We certainly *do* want to be able to boot  both
old and new Linux kernels and to switch between their different
interfaces in runtime.

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
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