Re: [PATCH 3/3] xen/arm: Add i.MX8QM platform support

[Julien Grall <julien@xen.org>]

Hi Peng,

On 28/02/2022 01:07, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>   xen/arch/arm/Kconfig.debug      |  3 +++
>   xen/arch/arm/platforms/Makefile |  1 +
>   xen/arch/arm/platforms/imx8qm.c | 44 +++++++++++++++++++++++++++++++++
>   3 files changed, 48 insertions(+)
>   create mode 100644 xen/arch/arm/platforms/imx8qm.c
> 
> diff --git a/xen/arch/arm/Kconfig.debug b/xen/arch/arm/Kconfig.debug
> index 9ecb446b3a..43ccd8fe62 100644
> --- a/xen/arch/arm/Kconfig.debug
> +++ b/xen/arch/arm/Kconfig.debug
> @@ -143,6 +143,9 @@ choice
>   	config EARLY_PRINTK_HIKEY960
>   		bool "Early printk with pl011 with Hikey 960"
>   		select EARLY_UART_PL011
> +	config EARLY_PRINTK_IMX8QM
> +		bool "Early printk with i.MX LPUART with i.MX8QM"
> +		select EARLY_UART_IMX_LPUART

The goal of platform specific early printk is to select to UART address 
(see EARLY_UART_BASE_ADDRESS).

However, we have deprecated them. So we should avoid adding new ones.

>   	config EARLY_PRINTK_JUNO
>   		bool "Early printk with pl011 on Juno platform"
>   		select EARLY_UART_PL011
> diff --git a/xen/arch/arm/platforms/Makefile b/xen/arch/arm/platforms/Makefile
> index 8632f4115f..bec6e55d1f 100644
> --- a/xen/arch/arm/platforms/Makefile
> +++ b/xen/arch/arm/platforms/Makefile
> @@ -9,5 +9,6 @@ obj-$(CONFIG_ALL_PLAT)   += sunxi.o
>   obj-$(CONFIG_ALL64_PLAT) += thunderx.o
>   obj-$(CONFIG_ALL64_PLAT) += xgene-storm.o
>   obj-$(CONFIG_ALL64_PLAT) += brcm-raspberry-pi.o
> +obj-$(CONFIG_ALL64_PLAT) += imx8qm.o
>   obj-$(CONFIG_MPSOC_PLATFORM)  += xilinx-zynqmp.o
>   obj-$(CONFIG_MPSOC_PLATFORM)  += xilinx-zynqmp-eemi.o
> diff --git a/xen/arch/arm/platforms/imx8qm.c b/xen/arch/arm/platforms/imx8qm.c
> new file mode 100644
> index 0000000000..289c18e5f9
> --- /dev/null
> +++ b/xen/arch/arm/platforms/imx8qm.c
> @@ -0,0 +1,44 @@
> +/*
> + * xen/arch/arm/platforms/imx8qm.c
> + *
> + * i.MX 8QM setup
> + *
> + * Copyright 2022 NXP
> + *
> + * Peng Fan <peng.fan@nxp.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <xen/delay.h>
> +#include <xen/mm.h>
> +#include <xen/vmap.h>
> +#include <asm/io.h>
> +#include <asm/platform.h>
> +
> +static const char * const imx8qm_dt_compat[] __initconst =
> +{
> +    "fsl,imx8qm",
> +    NULL
> +};
> +
> +PLATFORM_START(imx8qm, "i.MX 8")
> +    .compatible = imx8qm_dt_compat,
> +PLATFORM_END

We are only adding new platform definition when quirks are necessary. Do 
you need specific quirks for the i.MX8QM?

A somewhat related question, is this series enough to boot Xen upstream 
on the board?

Cheers,

-- 
Julien Grall