[U-Boot-Users] [PATCH] PPC4xx: Minimal changes to add vxWorks support

[Jerry Van Baren]

Niklaus Giger wrote:
> Hi
> 
> I have to support vxWorks on our boards. In order to avoid changing the TLB
> in all PPC440x based boards  I need this small patch. Can it go into the
> git repository or do I have to maintain it out of the tree forever?
> 
> Best regards
> 
> Signed-off-by: Niklaus Giger <niklaus.giger at netstal.com>
> ---
>  cpu/ppc4xx/start.S |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/cpu/ppc4xx/start.S b/cpu/ppc4xx/start.S
> index 9626b65..8f19444 100644
> --- a/cpu/ppc4xx/start.S
> +++ b/cpu/ppc4xx/start.S
> @@ -1432,7 +1432,10 @@ relocate_code:
>  	dccci	0,0			/* Invalidate data cache, now no longer our stack */
>  	sync
>  	isync
> -	addi	r1,r0,0x0000		/* TLB entry #0 */
> +#ifndef CFG_TLB_FOR_BOOT_FLASH
> +#define CFG_TLB_FOR_BOOT_FLASH 0
> +#endif
> +	addi	r1,r0,CFG_TLB_FOR_BOOT_FLASH	/* TLB entry (default #0) */
>  	tlbre	r0,r1,0x0002		/* Read contents */
>  	ori	r0,r0,0x0c00		/* Or in the inhibit, write through bit */
>  	tlbwe	r0,r1,0x0002		/* Save it out */

Hi Niklaus,

I don't know the answer to your question, but the following alternate 
construct is cleaner (and cleaner may help get acceptance ;-):

#ifdef CFG_TLB_FOR_BOOT_FLASH
	addi	r1,r0,CFG_TLB_FOR_BOOT_FLASH	/* Use defined TLB */
#else
	addi	r1,r0,0x0000		/* Default TLB entry is #0 */
#endif

Best regards,
gvb