RE: [PATCH v2 01/10] xen/arm: Print a 64-bit number in hex from early uart

[Jiamei Xie <Jiamei.Xie@xxxxxxx>]

Hi Wei,

> -----Original Message-----
> From: Xen-devel <xen-devel-bounces@xxxxxxxxxxxxxxxxxxxx> On Behalf Of
> Wei Chen
> Sent: 2022年4月18日 17:07
> To: --to=xen-devel@xxxxxxxxxxxxxxxxxxxx; xen-devel@xxxxxxxxxxxxxxxxxxxx
> Cc: nd <nd@xxxxxxx>; Wei Chen <Wei.Chen@xxxxxxx>; Stefano Stabellini
> <sstabellini@xxxxxxxxxx>; Julien Grall <julien@xxxxxxx>; Bertrand Marquis
> <Bertrand.Marquis@xxxxxxx>; Volodymyr Babchuk
> <Volodymyr_Babchuk@xxxxxxxx>; Julien Grall <jgrall@xxxxxxxxxx>
> Subject: [PATCH v2 01/10] xen/arm: Print a 64-bit number in hex from early
> uart
> 
> Current putn function that is using for early print
> only can print low 32-bit of AArch64 register. This
> will lose some important messages while debugging
> with early console. For example:
> (XEN) Bringing up CPU5
> - CPU 0000000100000100 booting -
> Will be truncated to
> (XEN) Bringing up CPU5
> - CPU 00000100 booting -
> 
> In this patch, we increased the print loops and shift
> bits to make putn print 64-bit number.
> 
> Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
> Acked-by: Julien Grall <jgrall@xxxxxxxxxx>
> ---
>  xen/arch/arm/arm64/head.S | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S
> index e62c48ec1c..2bb7906f69 100644
> --- a/xen/arch/arm/arm64/head.S
> +++ b/xen/arch/arm/arm64/head.S
> @@ -866,17 +866,19 @@ puts:
>          ret
>  ENDPROC(puts)
> 
> -/* Print a 32-bit number in hex.  Specific to the PL011 UART.
> +/*
> + * Print a 64-bit number in hex.
>   * x0: Number to print.
>   * x23: Early UART base address
> - * Clobbers x0-x3 */
> + * Clobbers x0-x3
> + */
>  putn:
>          adr   x1, hex
> -        mov   x3, #8
> +        mov   x3, #16
>  1:
>          early_uart_ready x23, 2
> -        and   x2, x0, #0xf0000000    /* Mask off the top nybble */
> -        lsr   x2, x2, #28
> +        and   x2, x0, #(0xf<<60)     /* Mask off the top nybble */
> +        lsr   x2, x2, #60
>          ldrb  w2, [x1, x2]           /* Convert to a char */
>          early_uart_transmit x23, w2
>          lsl   x0, x0, #4             /* Roll it through one nybble at a time 
> */
> --
> 2.25.1
> 

I have tested the whole patch series on Armv8A(config without NUMA) and 
X86(config with NUMA), both can enter Dom0 successfully and the X86 NUMA works 
normally.

Tested-by: Jiamei Xie <jiamei.xie@xxxxxxx> 

Regards,
Jiamei Xie