[PATCH v2 1/2] xilinx: board: Update the kaslr-seed property

[Michal Simek]

On 1/16/24 05:50, 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 | 50 +++++++++++++++++++++++++++++++++++++
>   1 file changed, 50 insertions(+)
> 
> diff --git a/board/xilinx/common/board.c b/board/xilinx/common/board.c
> index 12a877c715..2796d45351 100644
> --- a/board/xilinx/common/board.c
> +++ b/board/xilinx/common/board.c
> @@ -25,6 +25,7 @@
>   #include <i2c_eeprom.h>
>   #include <net.h>
>   #include <generated/dt.h>
> +#include <rng.h>
>   #include <slre.h>
>   #include <soc.h>
>   #include <linux/ctype.h>
> @@ -682,3 +683,52 @@ phys_addr_t board_get_usable_ram_top(phys_size_t total_size)
>   	return reg + size;
>   }
>   #endif
> +
> +#ifdef CONFIG_OF_BOARD_SETUP
> +#define MAX_RAND_SIZE 8
> +int ft_board_setup(void *blob, struct bd_info *bd)
> +{
> +	size_t n = MAX_RAND_SIZE;
> +	struct udevice *dev;
> +	u8 buf[MAX_RAND_SIZE];
> +	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 -EINVAL;

Why did you changed it from 0?

Pretty much this change breaks all current SOMs with saved variables because 
most of them doesn't really start TPM.

I would say return 0 here.


> +	}
> +
> +	if (dm_rng_read(dev, buf, n)) {
> +		debug("Reading RNG failed\n");
> +		return -EINVAL;

return 0 here.

> +	}
> +
> +	if (!blob) {
> +		debug("No FDT memory address configured. Please configure\n"
> +		      "the FDT address via \"fdt addr <address>\" command.\n"
> +		      "Aborting!\n");
> +		return -EINVAL;

return 0

> +	}
> +
> +	ret = fdt_check_header(blob);
> +	if (ret < 0) {
> +		debug("fdt_chosen: %s\n", fdt_strerror(ret));
> +		return -EINVAL;

no reason to make own return code

return ret;

> +	}
> +
> +	nodeoffset = fdt_find_or_add_subnode(blob, 0, "chosen");
> +	if (nodeoffset < 0) {
> +		debug("Reading chosen node failed\n");
> +		return -EINVAL;

return ret;

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

return ret;

> +	}
> +
> +	return ret;

return 0;

> +}
> +#endif

M