Unverified Commit 26428e7d authored by Simon Glass's avatar Simon Glass Committed by Nathan Chancellor
Browse files

scripts/make_fit: Support an initial ramdisk 



FIT (Flat Image Tree) allows a ramdisk to be included in each
configuration. Add support for this to the script.

This feature is not available via 'make image.fit' since the ramdisk
likely needs to be built separately anyway, e.g. using modules from
the kernel build. Future work may provide support for doing that.

Note that the uncompressed size is not correct when a ramdisk is used,
since it is too expensive to decompress the ramdisk.

Signed-off-by: default avatarSimon Glass <sjg@chromium.org>
Reviewed-by: default avatarNicolas Schier <nsc@kernel.org>
Reviewed-by: default avatarAhmad Fatoum <a.fatoum@pengutronix.de>
Link: https://patch.msgid.link/20260106162738.2605574-3-sjg@chromium.org


Signed-off-by: default avatarNathan Chancellor <nathan@kernel.org>
parent 621fd65a

scripts/make_fit.py

+44 −8
Original line number Diff line number Diff line
@@ -10,10 +10,14 @@ 
Usage:

    make_fit.py -A arm64 -n 'Linux-6.6' -O linux

        -o arch/arm64/boot/image.fit -k /tmp/kern/arch/arm64/boot/image.itk

        @arch/arm64/boot/dts/dtbs-list -E -c gzip

        -r /boot/initrd.img-6.14.0-27-generic @arch/arm64/boot/dts/dtbs-list

        -E -c gzip



Creates a FIT containing the supplied kernel and a set of devicetree files,

either specified individually or listed in a file (with an '@' prefix).

Creates a FIT containing the supplied kernel, an optional ramdisk, and a set of

devicetree files, either specified individually or listed in a file (with an

'@' prefix).



Use -r to specify an existing ramdisk/initrd file.



Use -E to generate an external FIT (where the data is placed after the

FIT data structure). This allows parsing of the data without loading
@@ -29,8 +33,6 @@ looks at the .cmd files produced by the kernel build. 


The resulting FIT can be booted by bootloaders which support FIT, such

as U-Boot, Linuxboot, Tianocore, etc.



Note that this tool does not yet support adding a ramdisk / initrd.

"""



import argparse
@@ -81,6 +83,8 @@ def parse_args(): 
          help='Specifies the operating system')

    parser.add_argument('-k', '--kernel', type=str, required=True,

          help='Specifies the (uncompressed) kernel input file (.itk)')

    parser.add_argument('-r', '--ramdisk', type=str,

          help='Specifies the ramdisk/initrd input file')

    parser.add_argument('-v', '--verbose', action='store_true',

                        help='Enable verbose output')

    parser.add_argument('dtbs', type=str, nargs='*',
@@ -133,7 +137,28 @@ def write_kernel(fsw, data, args): 
        fsw.property_u32('entry', 0)





def finish_fit(fsw, entries):

def write_ramdisk(fsw, data, args):

    """Write out the ramdisk image



    Writes a ramdisk node along with the required properties



    Args:

        fsw (libfdt.FdtSw): Object to use for writing

        data (bytes): Data to write (possibly compressed)

        args (Namespace): Contains necessary strings:

            arch: FIT architecture, e.g. 'arm64'

            fit_os: Operating Systems, e.g. 'linux'

    """

    with fsw.add_node('ramdisk'):

        fsw.property_string('description', 'Ramdisk')

        fsw.property_string('type', 'ramdisk')

        fsw.property_string('arch', args.arch)

        fsw.property_string('compression', 'none')

        fsw.property_string('os', args.os)

        fsw.property('data', data)





def finish_fit(fsw, entries, has_ramdisk=False):

    """Finish the FIT ready for use



    Writes the /configurations node and subnodes
@@ -143,6 +168,7 @@ def finish_fit(fsw, entries): 
        entries (list of tuple): List of configurations:

            str: Description of model

            str: Compatible stringlist

        has_ramdisk (bool): True if a ramdisk is included in the FIT

    """

    fsw.end_node()

    seq = 0
@@ -154,6 +180,8 @@ def finish_fit(fsw, entries): 
                fsw.property_string('description', model)

                fsw.property('fdt', bytes(''.join(f'fdt-{x}\x00' for x in files), "ascii"))

                fsw.property_string('kernel', 'kernel')

                if has_ramdisk:

                    fsw.property_string('ramdisk', 'ramdisk')

    fsw.end_node()
@@ -274,6 +302,14 @@ def build_fit(args): 
    size += os.path.getsize(args.kernel)

    write_kernel(fsw, comp_data, args)



    # Handle the ramdisk if provided. Compression is not supported as it is

    # already compressed.

    if args.ramdisk:

        with open(args.ramdisk, 'rb') as inf:

            data = inf.read()

        size += len(data)

        write_ramdisk(fsw, data, args)



    for fname in args.dtbs:

        # Ignore non-DTB (*.dtb) files

        if os.path.splitext(fname)[1] != '.dtb':
@@ -296,12 +332,12 @@ def build_fit(args): 


        entries.append([model, compat, files_seq])



    finish_fit(fsw, entries)

    finish_fit(fsw, entries, bool(args.ramdisk))



    # Include the kernel itself in the returned file count

    fdt = fsw.as_fdt()

    fdt.pack()

    return fdt.as_bytearray(), seq + 1, size

    return fdt.as_bytearray(), seq + 1 + bool(args.ramdisk), size





def run_make_fit():