[U-Boot] [PATCH] arm64: zynqmp: Create fdtfile from compatible string

[Alexander Graf]

On 14.02.19 13:18, Michal Simek wrote:
> distro boot expects that fdtfile name is setup for alternative DTB.
> Create this file based on the first platform compatible string.
> This should ensure that one rootfs can store multiple DTBs for different
> boards.
> 
> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
> ---
> 
> How good/bad idea is this?
> 
> ---
>  board/xilinx/zynqmp/zynqmp.c | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
> 
> diff --git a/board/xilinx/zynqmp/zynqmp.c b/board/xilinx/zynqmp/zynqmp.c
> index a49f2f3e9ebe..64800d869819 100644
> --- a/board/xilinx/zynqmp/zynqmp.c
> +++ b/board/xilinx/zynqmp/zynqmp.c
> @@ -514,6 +514,32 @@ static u32 reset_reason(void)
>  	return ret;
>  }
>  
> +static int set_fdtfile(void)
> +{
> +	char *compatible, *fdtfile;
> +
> +	if (env_get("fdtfile"))
> +		return 0;
> +
> +	compatible = (char *)fdt_getprop(gd->fdt_blob, 0, "compatible", NULL);
> +	if (compatible) {
> +		debug("Compatible: %s\n", compatible);
> +
> +		strsep(&compatible, ",");
> +
> +		fdtfile = calloc(1, strlen(compatible) + 4);
> +		if (!fdtfile)
> +			return -ENOMEM;
> +
> +		sprintf(fdtfile, "%s%s", compatible, ".dtb");

AArch64 dtbs are usually stored in a directory structure which you want
to match again. Is this the case for the compatible string? From a quick
glimpse, it looks like it - but please make sure that something is in
place to ensure it stays that way (upstream review for example).

So the only change I would make here is that this should be "xilinx/%s.dtb".

The idea itself seems sound to me.


Alex

> +
> +		env_set("fdtfile", fdtfile);
> +		free(fdtfile);
> +	}
> +
> +	return 0;
> +}
> +
>  int board_late_init(void)
>  {
>  	u32 reg = 0;
> @@ -536,6 +562,10 @@ int board_late_init(void)
>  		return 0;
>  	}
>  
> +	ret = set_fdtfile();
> +	if (ret)
> +		return ret;
> +
>  	ret = zynqmp_mmio_read((ulong)&crlapb_base->boot_mode, &reg);
>  	if (ret)
>  		return -EINVAL;
>