[PATCH 1/1] spl: add FIT support to semihosting boot method

[Sean Anderson]

On 7/22/23 15:27, Heinrich Schuchardt wrote:
> Allow loading a FIT image via semihosting in SPL.

I had previously attempted this in [1], which is a more general
approach. I put together a v4 earlier this year but I got sidetracked
before I sent it out. I'll see if I can finish it up this week.

--Sean

[1] https://lore.kernel.org/u-boot/20220505201655.645692-1-sean.anderson@seco.com/

> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> ---
>  common/spl/spl_semihosting.c | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
> 
> diff --git a/common/spl/spl_semihosting.c b/common/spl/spl_semihosting.c
> index 5b5e842a11..f7dd289286 100644
> --- a/common/spl/spl_semihosting.c
> +++ b/common/spl/spl_semihosting.c
> @@ -21,6 +21,23 @@ static int smh_read_full(long fd, void *memp, size_t len)
>  	return 0;
>  }
>  
> +static ulong smh_fit_read(struct spl_load_info *load, ulong file_offset,
> +			  ulong size, void *buf)
> +{
> +	long fd;
> +	ulong ret;
> +
> +	fd = smh_open(load->filename, MODE_READ | MODE_BINARY);
> +	if (fd < 0) {
> +		log_debug("could not open %s: %ld\n", load->filename, fd);
> +		return 0;
> +	}
> +	ret = smh_read(fd, buf, size);
> +	smh_close(fd);
> +
> +	return ret;
> +}
> +
>  static int spl_smh_load_image(struct spl_image_info *spl_image,
>  			      struct spl_boot_device *bootdev)
>  {
> @@ -49,6 +66,20 @@ static int spl_smh_load_image(struct spl_image_info *spl_image,
>  		goto out;
>  	}
>  
> +	if (IS_ENABLED(CONFIG_SPL_LOAD_FIT) &&
> +	    image_get_magic(header) == FDT_MAGIC) {
> +		struct spl_load_info load;
> +
> +		debug("Found FIT\n");
> +		load.read = smh_fit_read;
> +		load.bl_len = 1;
> +		load.filename = filename;
> +		load.priv = NULL;
> +		smh_close(fd);
> +
> +		return spl_load_simple_fit(spl_image, &load, 0, header);
> +	}
> +
>  	ret = spl_parse_image_header(spl_image, bootdev, header);
>  	if (ret) {
>  		log_debug("failed to parse image header: %d\n", ret);