[U-Boot] [PATCH] fit: Do not automatically decompress ramdisk images

[Simon Goldschmidt]

On Sat, Aug 3, 2019 at 12:52 AM Julius Werner <jwerner at chromium.org> wrote:
>
> The Linux ramdisk should always be decompressed by the kernel itself,
> not by U-Boot. Therefore, the 'compression' node in the FIT image should
> always be set to "none" for ramdisk images, since the only point of
> using that node is if you want U-Boot to do the decompression itself.
>
> Yet some systems populate the node to the compression algorithm used by
> the kernel instead. This used to be ignored, but now that we support
> decompression of all image types it becomes a problem. Since ramdisks
> should never be decompressed by U-Boot anyway, this patch adds a special
> exception for them to avoid these issues. Still, setting the
> 'compression' node like that is wrong in the first place, so we still
> want to print out a warning so that third-party distributions doing this
> can notice and fix it.
>
> Signed-off-by: Julius Werner <jwerner at chromium.org>

Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>

> ---
>  common/image-fit.c        | 13 +++++++++----
>  test/py/tests/test_fit.py | 10 +++++++++-
>  2 files changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/common/image-fit.c b/common/image-fit.c
> index e346fed550..5c63c769de 100644
> --- a/common/image-fit.c
> +++ b/common/image-fit.c
> @@ -1998,10 +1998,11 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
>         comp = IH_COMP_NONE;
>         loadbuf = buf;
>         /* Kernel images get decompressed later in bootm_load_os(). */
> -       if (!(image_type == IH_TYPE_KERNEL ||
> -             image_type == IH_TYPE_KERNEL_NOLOAD) &&
> -           !fit_image_get_comp(fit, noffset, &comp) &&
> -           comp != IH_COMP_NONE) {
> +       if (!fit_image_get_comp(fit, noffset, &comp) &&
> +           comp != IH_COMP_NONE &&
> +           !(image_type == IH_TYPE_KERNEL ||
> +             image_type == IH_TYPE_KERNEL_NOLOAD ||
> +             image_type == IH_TYPE_RAMDISK)) {
>                 ulong max_decomp_len = len * 20;
>                 if (load == data) {
>                         loadbuf = malloc(max_decomp_len);
> @@ -2021,6 +2022,10 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
>                 memcpy(loadbuf, buf, len);
>         }
>
> +       if (image_type == IH_TYPE_RAMDISK && comp != IH_COMP_NONE)
> +               puts("WARNING: 'compression' nodes for ramdisks are deprecated,"
> +                    " please fix your .its file!\n");
> +
>         /* verify that image data is a proper FDT blob */
>         if (image_type == IH_TYPE_FLATDT && fdt_check_header(loadbuf)) {
>                 puts("Subimage data is not a FDT");
> diff --git a/test/py/tests/test_fit.py b/test/py/tests/test_fit.py
> index 8009d2907b..e3210ed43f 100755
> --- a/test/py/tests/test_fit.py
> +++ b/test/py/tests/test_fit.py
> @@ -269,6 +269,11 @@ def test_fit(u_boot_console):
>      def check_equal(expected_fname, actual_fname, failure_msg):
>          """Check that a file matches its expected contents
>
> +        This is always used on out-buffers whose size is decided by the test
> +        script anyway, which in some cases may be larger than what we're
> +        actually looking for. So it's safe to truncate it to the size of the
> +        expected data.
> +
>          Args:
>              expected_fname: Filename containing expected contents
>              actual_fname: Filename containing actual contents
> @@ -276,6 +281,8 @@ def test_fit(u_boot_console):
>          """
>          expected_data = read_file(expected_fname)
>          actual_data = read_file(actual_fname)
> +        if len(expected_data) < len(actual_data):
> +            actual_data = actual_data[:len(expected_data)]
>          assert expected_data == actual_data, failure_msg
>
>      def check_not_equal(expected_fname, actual_fname, failure_msg):
> @@ -435,7 +442,8 @@ def test_fit(u_boot_console):
>              output = cons.run_command_list(cmd.splitlines())
>              check_equal(kernel, kernel_out, 'Kernel not loaded')
>              check_equal(control_dtb, fdt_out, 'FDT not loaded')
> -            check_equal(ramdisk, ramdisk_out, 'Ramdisk not loaded')
> +            check_not_equal(ramdisk, ramdisk_out, 'Ramdisk got decompressed?')
> +            check_equal(ramdisk + '.gz', ramdisk_out, 'Ramdist not loaded')
>
>
>      cons = u_boot_console
> --
> 2.20.1
>