[PATCH] firmware: Minor optimization in _scratch_init()

[Xiang W]

在 2021-07-08星期四的 21:35 +0800，Bin Meng写道：
> Before entering _scratch_init(), register t3 already holds a copy
> of the firmware end address, hence there is no need to calculate
> it again. This reduces 3 instructions in each _scratch_init() loop.
> 
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
Reviewed-by: Xiang W <wxjstz at 126.com>
> ---
> 
>  firmware/fw_base.S | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/firmware/fw_base.S b/firmware/fw_base.S
> index a5ce946..e35f18e 100644
> --- a/firmware/fw_base.S
> +++ b/firmware/fw_base.S
> @@ -287,10 +287,7 @@ _scratch_init:
>         /* Initialize scratch space */
>         /* Store fw_start and fw_size in scratch space */
>         lla     a4, _fw_start
> -       lla     a5, _fw_end
> -       mul     t0, s7, s8
> -       add     a5, a5, t0
> -       sub     a5, a5, a4
> +       sub     a5, t3, a4
>         REG_S   a4, SBI_SCRATCH_FW_START_OFFSET(tp)
>         REG_S   a5, SBI_SCRATCH_FW_SIZE_OFFSET(tp)
>         /* Store next arg1 in scratch space */
> -- 
> 2.25.1
> 
>