[U-Boot-Users] address question in lib_ppc/board.c

[wyu hotmail]

Hi, 

Thanks first.
In my first email, "_led is 0xfffaca58" should be "_end is 0xfffaca58", 
It's my mistake.
I can't understand that why reloc_off can be < 0, but after reading Masao's 
mail, I got it.
Thanks,

yuwp

>From: Wolfgang Denk <wd at denx.de>
>To: "wyu hotmail" <santerash at hotmail.com>
>CC: u-boot-users at lists.sourceforge.net
>Subject: Re: [U-Boot-Users] address question in lib_ppc/board.c 
>Date: Wed, 02 Jun 2004 15:37:10 +0200
>
>In message <Sea2-F14V7nOh9KvpvD000014b0 at hotmail.com> you wrote:
> >
> > I'm porting my custom PPC405EP board from bubinga405ep board, now I 
have a
> > question about macro CFG_MONITOR_BASE:
> > In include/configs/BUBINGA405EP.h, CFG_MONITOR_BASE was defined as
> > 0xFFF80000, base address of FLASH.
>
>Correct.
>
> > in function board_init_f:
> > 	len = (ulong)&_end - CFG_MONITOR_BASE;
> > Here, _led is 0xfffaca58
>
>What's "_led" here?
>
> > But in function board_init_r:
> >            gd->reloc_off = dest_addr - CFG_MONITOR_BASE;
> > Here, dest_addr is an address in SDRAM, in my board, dest_addr = 
0x1fd3000,
>
>Looks good to me.
>
> > that is, dest_addr < CFG_MONITOR_BASE. How to understand this?
>
>Well, we're going to relocate the code  to  RAM.  RAM  is  mapped  at
>0x0000,  so  all  RAM  addresses  will  always  be smaller then flash
>addresses.
>
>What exactly is your problem?
>
>Best regards,
>
>Wolfgang Denk
>
>--
>Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
>Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
>EMACS belongs in <sys/errno.h>: Editor too big!