Re: [Xen-devel] [PATCH 2/4] xen/arm64: do not clobber callee saved register in early_putch

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Mon, 13 May 2013, Ian Campbell wrote:
> x23 is callee saved in the ARM 64 bit calling convention. Use x15 instead
> which is a temporary register which need not be preserved.
> 
> Fixes a random crash during boot.
> 
> Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>

Acked-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>


>  xen/arch/arm/arm64/debug.S |    6 +++---
>  1 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/xen/arch/arm/arm64/debug.S b/xen/arch/arm/arm64/debug.S
> index f0c7761..38b7c74 100644
> --- a/xen/arch/arm/arm64/debug.S
> +++ b/xen/arch/arm/arm64/debug.S
> @@ -27,9 +27,9 @@
>  /* Print a character on the UART - this function is called by C
>   * x0: character to print */
>  early_putch:
> -        ldr   x23, =FIXMAP_ADDR(FIXMAP_CONSOLE)
> -        early_uart_ready x23, 1
> -        early_uart_transmit x23, w0
> +        ldr   x15, =FIXMAP_ADDR(FIXMAP_CONSOLE)
> +        early_uart_ready x15, 1
> +        early_uart_transmit x15, w0
>          ret
>  
>  /*
> -- 
> 1.7.2.5
> 

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel