[RFC PATCH 2/2] fpga: xilinx: allow loading authenticated images (DDR)

[Michal Simek]

On 10/5/21 1:13 PM, Jorge Ramirez-Ortiz wrote:
> Add new compatible string u-boot,zynqmp-fpga-ddrauth to handle this
> use case.
> 
> Signed-off-by: Jorge Ramirez-Ortiz <jorge at foundries.io>
> ---
>  drivers/fpga/xilinx.c   | 29 +++++++++++++++++++++++++----
>  drivers/fpga/zynqmppl.c |  4 ++--
>  include/xilinx.h        |  2 +-
>  3 files changed, 28 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/fpga/xilinx.c b/drivers/fpga/xilinx.c
> index cbebefb55f..c8035105e2 100644
> --- a/drivers/fpga/xilinx.c
> +++ b/drivers/fpga/xilinx.c
> @@ -135,23 +135,44 @@ int fpga_loadbitstream(int devnum, char *fpgadata, size_t size,
>  	dataptr += 4;
>  	printf("  bytes in bitstream = %d\n", swapsize);
>  
> -	return fpga_load(devnum, dataptr, swapsize, bstype);
> +	return fpga_load(devnum, dataptr, swapsize, bstype, NULL);
>  }
>  
>  int xilinx_load(xilinx_desc *desc, const void *buf, size_t bsize,
> -		bitstream_type bstype)
> +		bitstream_type bstype, const char *compatible)
>  {
> +	struct fpga_secure_info info = { 0 };
> +
>  	if (!xilinx_validate (desc, (char *)__FUNCTION__)) {
>  		printf ("%s: Invalid device descriptor\n", __FUNCTION__);
>  		return FPGA_FAIL;
>  	}
>  
> -	if (!desc->operations || !desc->operations->load) {
> +	if (!desc->operations) {
>  		printf("%s: Missing load operation\n", __func__);
>  		return FPGA_FAIL;
>  	}
>  
> -	return desc->operations->load(desc, buf, bsize, bstype);
> +	if (!compatible || !strcmp(compatible, "u-boot,fpga-legacy")) {
> +		if (!desc->operations->load) {
> +			printf("%s: Missing load operation\n", __func__);
> +			return FPGA_FAIL;
> +		}
> +		return desc->operations->load(desc, buf, bsize, bstype);
> +	}
> +
> +	if (!strcmp(compatible, "u-boot,zynqmp-fpga-ddrauth")) {
> +		if (!desc->operations->loads) {
> +			printf("%s: Missing load operation\n", __func__);
> +			return FPGA_FAIL;
> +		}
> +		/* DDR authentication */
> +		info.authflag = 1;
> +		return desc->operations->loads(desc, buf, bsize, &info);
> +	}

I am not sure about this solution. First of all it forces SPL to have
additional code which just extending size. It means there must be a way
to enable/disable it.

The next thing is that you have zynqmp string in generic xilinx file
which doesn't look right. It would be better to deal with image types
directly in driver which is capable to handle it.
It means record fit image compatible string in the driver with
hooks/flags and determined what should be called.

And the same style should work for SPL and also for U-Boot proper.

Thanks,
Michal