[U-Boot] Got u-boot-2012.10 running on at91sam9200 - but why does it work?

[Jens Scharsig]

Hello Arvid,
Am 2013-10-09 21:23, schrieb Arvid Brodin:
> Hi,
> 
> I managed to get u-boot-2012.10 to boot from NOR flash on a custom 
> at91rm9200 board by doing this:
> 
> 
> Signed-off-by: Arvid Brodin <arvid.brodin at xdin.com>
> ---
>  arch/arm/cpu/arm920t/start.S   | 8 +++-----
>  2 files changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/arm/cpu/arm920t/start.S b/arch/arm/cpu/arm920t/start.S
> index 14c9156..efc4ea3 100644
> --- a/arch/arm/cpu/arm920t/start.S
> +++ b/arch/arm/cpu/arm920t/start.S
> @@ -294,9 +294,7 @@ clbss_e:
>  _nand_boot_ofs:
>  	.word nand_boot
>  #else
> -	ldr	r0, _board_init_r_ofs
> -	adr	r1, _start
> -	add	lr, r0, r1
> +	ldr	lr, _board_init_r
>  	add	lr, lr, r9
>  	/* setup parameters for board_init_r */
>  	mov	r0, r5		/* gd_t */
> @@ -304,8 +302,8 @@ _nand_boot_ofs:
>  	/* jump to it ... */
>  	mov	pc, lr
>  
> -_board_init_r_ofs:
> -	.word board_init_r - _start
> +_board_init_r:
> +	.word board_init_r
>  #endif
>  
>  _rel_dyn_start_ofs:
> 

you don't need change start.s to boot from NOR.
If shold set the  #define CONFIG_SYS_TEXT_BASE  0x00000000

Please see the configuration for eb_cpux9k2 board. This board does boot
from NOR with u-boot 2012.10.

BTW
The release 2012.10 is out of date. You should upadte to the current one (2013.10-rc4)

Best regards

Jens