[PATCH 1/2] xilinx: board: Update the kaslr-seed property

[Michal Simek]

On 1/12/24 07:10, Venkatesh Yadav Abbarapu wrote:
> Create a ft_board_setup() api that gets called as part
> of bootm/booti before jumping to kernel. In this
> ft_board_setup() callback that will inspect the DTB
> and insert the device tree blob with the "kaslr-seed" property.
> 
> Signed-off-by: Michal Simek <michal.simek at amd.com>
> Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu at amd.com>
> ---
>   board/xilinx/common/board.c | 59 +++++++++++++++++++++++++++++++++++++
>   1 file changed, 59 insertions(+)
> 
> diff --git a/board/xilinx/common/board.c b/board/xilinx/common/board.c
> index 12a877c715..985a3825e6 100644
> --- a/board/xilinx/common/board.c
> +++ b/board/xilinx/common/board.c
> @@ -682,3 +682,62 @@ phys_addr_t board_get_usable_ram_top(phys_size_t total_size)
>   	return reg + size;
>   }
>   #endif
> +
> +#ifdef CONFIG_OF_BOARD_SETUP
> +int ft_board_setup(void *blob, struct bd_info *bd)
> +{
> +	size_t n = 0x8;

this is pretty much macro not variable.

> +	struct udevice *dev;
> +	u64 *buf;
> +	int nodeoffset;
> +	int ret;

put it on the same line.

> +
> +	if (uclass_get_device(UCLASS_RNG, 0, &dev) || !dev) {
> +		debug("No RNG device\n");
> +		return 0;
> +	}
> +
> +	buf = malloc(n);
> +	if (!buf) {
> +		debug("Out of memory\n");
> +		return 0;
> +	}

Does it really make sense to call malloc and complicate error part just for 8bytes?
You can simply create array/variable on stack for it instead and it would be 
simpler and faster.



> +
> +	if (dm_rng_read(dev, buf, n)) {
> +		debug("Reading RNG failed\n");
> +		ret = 0;
> +		goto end;
> +	}
> +
> +	if (!blob) {
> +		debug("No FDT memory address configured. Please configure\n"
> +		      "the FDT address via \"fdt addr <address>\" command.\n"
> +		      "Aborting!\n");
> +		ret = 0;
> +		goto end;
> +	}
> +
> +	ret = fdt_check_header(blob);
> +	if (ret < 0) {
> +		printf("fdt_chosen: %s\n", fdt_strerror(ret));

this error is weird. Can you make it more understandable?

> +		goto end;
> +	}
> +
> +	nodeoffset = fdt_find_or_add_subnode(blob, 0, "chosen");
> +	if (nodeoffset < 0) {
> +		printf("Reading chosen node failed\n");

here too. You get this error in boot and you have no idea where this is coming 
from.

There is going to be error printed from code like
"ERROR: board-specific fdt fixup failed"

Maybe it should be enough to simply move all these messages under debug just in 
case and let code which calls this function to handle it.

> +		ret = -EINVAL;
> +		goto end;
> +	}
> +
> +	ret = fdt_setprop(blob, nodeoffset, "kaslr-seed", buf, sizeof(buf));
> +	if (ret < 0) {
> +		printf("Unable to set kaslr-seed on chosen node: %s\n", fdt_strerror(ret));
> +		goto end;
> +	}
> +end:
> +	free(buf);
> +
> +	return ret;
> +}
> +#endif

M