[U-Boot] fit image: boot gzipped ramdisk does not work anymore

Heiko Schocher hs at denx.de
Thu Aug 1 14:38:51 UTC 2019

Hello Simon,

Am 01.08.2019 um 14:33 schrieb Simon Goldschmidt:
> Am 01.08.2019 um 10:06 schrieb Heiko Schocher:
>> Hello Julius,
>> since your commit (just gone into mainline):
>> b1307f884a91 ("fit: Support compression for non-kernel components (e.g. FDT)")
>> I see on an imx6ull based board when booting (FIT image with kernel, dtb
>> and initramdisk), fit image source created from yocto, see [1]:
>> ## Loading kernel from FIT Image at 84000000 ...
>>      Using 'conf at imx6ull-k30rf.dtb' configuration
>>      Trying 'kernel at 1' kernel subimage
>>        Description:  Linux kernel
>>        Type:         Kernel Image
>>        Compression:  uncompressed
>>        Data Start:   0x840000e8
>>        Data Size:    5154568 Bytes = 4.9 MiB
>>        Architecture: ARM
>>        OS:           Linux
>>        Load Address: 0x82000000
>>        Entry Point:  0x82000000
>>        Hash algo:    sha1
>>        Hash value:   a3ba8a09b197c0d1acab834c69c5aea677d4a092
>>      Verifying Hash Integrity ... sha1+ OK
>> ## Loading ramdisk from FIT Image at 84000000 ...
>>      Using 'conf at imx6ull-k30rf.dtb' configuration
>>      Trying 'ramdisk at 1' ramdisk subimage
>>        Description:  k30rf-image-initramfs
>>        Type:         RAMDisk Image
>>        Compression:  gzip compressed
>>        Data Start:   0x844f0cf8
>>        Data Size:    6769496 Bytes = 6.5 MiB
>>        Architecture: ARM
>>        OS:           Linux
>>        Load Address: unavailable
>>        Entry Point:  unavailable
>>        Hash algo:    sha1
>>        Hash value:   507d8b20b18f9bca0e9178c48f634df5da720f65
>>      Verifying Hash Integrity ... sha1+ OK
>>      Uncompressing RAMDisk Image
>> Error: Bad gzipped data
>> Error decompressing ramdisk
>> Ramdisk image is corrupt or invalid
>> =>
>> I found your commit with "git bisect":
>> hs at xmglap:u-boot  [(kein Branch, binäre Suche begonnen bei master)] $ git bisect good
>> b1307f884a913f52a201491053b6d221c4204f60 is the first bad commit
>> commit b1307f884a913f52a201491053b6d221c4204f60
>> Author: Julius Werner <jwerner at chromium.org>
>> Date:   Wed Jul 24 19:37:55 2019 -0700
>>       fit: Support compression for non-kernel components (e.g. FDT)
>>       This patch adds support for compressing non-kernel image nodes in a FIT
>>       image (kernel nodes could already be compressed previously). This can
>>       reduce the size of FIT images and therefore improve boot times
>>       (especially when an image bundles many different kernel FDTs). The
>>       images will automatically be decompressed on load.
>>       This patch does not support extracting compatible strings from
>>       compressed FDTs, so it's not very helpful in conjunction with
>>       CONFIG_FIT_BEST_MATCH yet, but it can already be used in environments
>>       that select the configuration to load explicitly.
>>       Signed-off-by: Julius Werner <jwerner at chromium.org>
>>       Reviewed-by: Simon Glass <sjg at chromium.org>
>>       Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>
>> :040000 040000 6280a41241c1c25a28845fa526c5c958e448e347 e3f8ed43853541f868676f077924e7ab242d4da6 M
>>      common
>> :040000 040000 406b0c50c03633bad9d4a576d5662f4fa483fc6f 601624cee600c1c06640858519d93188cc312544 M
>>      test
>> hs at xmglap:u-boot  [(kein Branch, binäre Suche begonnen bei master)] $ git bisect log
>> git bisect start
>> # bad: [bbaf56eda0e63d6d28fbccae0f112ef88203eb4d] Merge tag 'u-boot-amlogic-20190731' of
>> https://gitlab.denx.de/u-boot/custodians/u-boot-amlogic
>> git bisect bad bbaf56eda0e63d6d28fbccae0f112ef88203eb4d
>> # good: [a9aa4c5700c68c070d63a391b51ea8d341b6e8a6] Merge branch '2019-07-24-master-imports'
>> git bisect good a9aa4c5700c68c070d63a391b51ea8d341b6e8a6
>> # good: [75551c8bfc9545e31ec2ce238cac3857904007b8] Merge branch '2019-07-26-ti-imports'
>> git bisect good 75551c8bfc9545e31ec2ce238cac3857904007b8
>> # bad: [333755ef7b6f824366eed37ae068c20a4f25a123] Merge branch '2019-07-29-ti-imports'
>> git bisect bad 333755ef7b6f824366eed37ae068c20a4f25a123
>> # good: [26008cd42b590dc71ee9c1ca667a218542aab342] rockchip: rv1108: Migrate to use common board file
>> git bisect good 26008cd42b590dc71ee9c1ca667a218542aab342
>> # good: [92430b8fc8aac3b4ab92e9ca8a09d83c4788c609] Merge
>> https://gitlab.denx.de/u-boot/custodians/u-boot-socfpga
>> git bisect good 92430b8fc8aac3b4ab92e9ca8a09d83c4788c609
>> # bad: [2d64a0f7e952f54375702fb2b854461e402ded9d] Merge branch '2019-07-29-master-imports'
>> git bisect bad 2d64a0f7e952f54375702fb2b854461e402ded9d
>> # bad: [49b10cb4926285b856b207c1f5bb40c75487f08b] gpio: fixes for gpio-hog support
>> git bisect bad 49b10cb4926285b856b207c1f5bb40c75487f08b
>> # bad: [e35d533c79c75e9ad68a2e78da52c8ce58e6ce0d] tools/logos: remove black background of U-Boot logo
>> git bisect bad e35d533c79c75e9ad68a2e78da52c8ce58e6ce0d
>> # bad: [b1307f884a913f52a201491053b6d221c4204f60] fit: Support compression for non-kernel components
>> (e.g. FDT)
>> git bisect bad b1307f884a913f52a201491053b6d221c4204f60
>> # good: [2090854cd2f228bab546f2718ccdbe1664830d3c] common: Move bootm_decomp_image() to image.c (as
>> image_decomp())
>> git bisect good 2090854cd2f228bab546f2718ccdbe1664830d3c
>> # first bad commit: [b1307f884a913f52a201491053b6d221c4204f60] fit: Support compression for
>> non-kernel components (e.g. FDT)
>> hs at xmglap:u-boot  [(kein Branch, binäre Suche begonnen bei master)] $
>> base was current master:
>> *   bbaf56eda0 - Merge tag 'u-boot-amlogic-20190731' of
>> https://gitlab.denx.de/u-boot/custodians/u-boot-amlogic
>> I am currently not in my office to dig deeper into it ... may you have an idea?
>> Thanks!
>> bye,
>> Heiko
>> [1] fit image source (created from yocto)
>> /dts-v1/;
>> / {
>>           description = "U-Boot fitImage for Poky (Yocto Project Reference Distro)/4.19.59/k30rf";
>>           #address-cells = <1>;
>>           images {
>> [...]
>>                   ramdisk at 1 {
>>                           description = "k30rf-image-initramfs";
>>                           data =
>> /incbin/("/work/hs/tbot2go/k30rf/repo/k30rf/build_k30rf/tmp/deploy/images/k30rf/k30rf-image-initramfs-k30rf.cpio.gz"); 
>>                           type = "ramdisk";
>>                           arch = "arm";
>>                           os = "linux";
>>                           compression = "gzip";
> Back last year, when I started what Julius succeeded with this pach, we came to the conclusion that 
> this "compression = " tag in the FIT image wasn't about the actual content but about what U-Boot 
> should do with the content. I.e. in your case it means "U-Boot, please uncompress this!", while the 
> old code just did not care about compression and left uncompression to the Kernel.


> To retain this behaviour, it should be enough to delete the "compression = " line from your its. 
> That way, U-Boot doesn't uncompress the ramdisk and the Kernel should do it like always.

Ah ... okay ... Hmm.. the its file gets created from yocto recipe:


I never checked :-(

So this commit breaks now yocto builded FIT images (for boards which use
FIT image with an compressed ramdisk)

Added Marek, as he introduced "Add basic fitImage support" in yocto.

Hmm... thinking while writting ... this breaks also boards which only
do an U-Boot update, and want to boot "old" FIT images from a storage
device... Do we really want this?

Your arguments are correct, and the commit also, but we perhaps break
some boards, so U-Boot should be able to handle the old (wrong) way?

The "compression = " line in the generated its file is added in
kernel-fitimage.class from commit:

commit 4aa6644f92975ded908ef99cf313466e0845e071
Author: Rick Altherr <raltherr at google.com>
Date:   Fri Jan 20 11:28:53 2017 -0800

     kernel-fitimage: Use compressed ramdisks in FIT images if available

     kernel-fitimage:fitimage_assemble() was calling copy_initramfs from
     kernel.bbclass which decompresses the initramfs cpio.  Assume that if
     INITRAMFS_FSTYPES includes a compressed cpio, that is what it desired in
     the FIT image.

     (From OE-Core rev: 842ad404b36e00c89f615a3f7db4a2d30062effa)

     Signed-off-by: Rick Altherr <raltherr at google.com>
     Signed-off-by: Ross Burton <ross.burton at intel.com>
     Signed-off-by: Richard Purdie <richard.purdie at linuxfoundation.org>

So more than 2 years in, so for sure boards out, which we break now ...

Added Rick, Ross and Richard to cc too, may they have an idea, what we
should do.

I think we should do:

- U-Boot Kconfig option: to set U-Boot into old (wrong) way
   or at least, ignore compressed line in ramdisk section. Last idea
   seems the best option for me, may we do this always?

- correct yocto class, to not set "compressed =" line in its file.


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