Re: [PATCH] MIPS: zboot: Avoid endless loop in clear BSS.

From: Jiaxun Yang
Date: Tue Jan 05 2021 - 21:06:17 EST




On Wed, Jan 6, 2021, at 8:47 AM, Jinyang He wrote:
> Commit 2ee1503e546f ("MIPS: zboot: head.S clean up").
>
> After .noreorder removed, clear BSS fall into endless loop. The bne
> instruction will add nop to the delay slot at compile time. So a0
> register will not increment by 4. Fix it and clear BSS from _edata
> to (_end - 1).

Oops, my fault.
My QEMU based local test setup somehow never really tested zboot.

Reviewed-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>

Thanks!

- Jiaxun

>
> Signed-off-by: Jinyang He <hejinyang@xxxxxxxxxxx>
> ---
> arch/mips/boot/compressed/head.S | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/mips/boot/compressed/head.S b/arch/mips/boot/compressed/head.S
> index 070b2fb..5795d0a 100644
> --- a/arch/mips/boot/compressed/head.S
> +++ b/arch/mips/boot/compressed/head.S
> @@ -26,8 +26,8 @@
> PTR_LA a0, _edata
> PTR_LA a2, _end
> 1: sw zero, 0(a0)
> + addiu a0, a0, 4
> bne a2, a0, 1b
> - addiu a0, a0, 4
>
> PTR_LA a0, (.heap) /* heap address */
> PTR_LA sp, (.stack + 8192) /* stack address */
> --
> 2.1.0
>
>

--
- Jiaxun