[U-Boot] [PATCH 1/4] mpc83xx: Make start.S true PIC

[Wolfgang Denk]

Dear Joakim Tjernlund,

In message <1292838435-14958-1-git-send-email-Joakim.Tjernlund at transmode.se> you wrote:
> Remove dependencies on link address. Use GOT and
> add an new function to calculate the actual address.
> 
> Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund at transmode.se>
> ---
>  arch/powerpc/cpu/mpc83xx/start.S |   35 +++++++++++++++++++++++++++--------
>  1 files changed, 27 insertions(+), 8 deletions(-)

It seems this code introduces some subtle changes.

> -	lis r4, (CONFIG_SYS_MONITOR_BASE)@h
> -	ori r4, r4, (CONFIG_SYS_MONITOR_BASE)@l
> -	addi r5, r4, in_flash - _start + EXC_OFF_SYS_RESET
> -	mtlr r5

The original code references CONFIG_SYS_MONITOR_BASE.

> +	bl	add_flash_base
...
> +add_flash_base:
> +	/* Check if already inside flash address space. */
> +	/* if so, do not add CONFIG_SYS_FLASH_BASE */
> +	lis	r4, (CONFIG_SYS_FLASH_BASE)@h
> +	ori	r4, r4, (CONFIG_SYS_FLASH_BASE)@l
> +	cmplw	cr0, r3, r4
> +	ble	cr0, 2f /* r3 < r4 ? */
> +	lis	r6, (CONFIG_SYS_FLASH_BASE+(CONFIG_SYS_FLASH_SIZE*1024*1024-1))@h
> +	ori	r6, r6, (CONFIG_SYS_FLASH_BASE+(CONFIG_SYS_FLASH_SIZE*1024*1024-1))@l
> +	cmplw	cr0, r3, r6
> +	blelr	cr0	 /* r3 < r6 ? */
> +2:	add	r3,r3,r4
> +	blr

But your new code does not reference CONFIG_SYS_MONITOR_BASE at all,
but uses CONFIG_SYS_FLASH_BASE instead.


On which boards has this been tested?

Best regards,

Wolfgang Denk

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