[PATCH 0/9] Nokia RX-51: Small cleanups and UBI boot test case

[Tony Dinh]

Thanks Damiel!

On Sun, Sep 4, 2022 at 3:10 PM Pali Rohár <pali at kernel.org> wrote:
>
> On Sunday 04 September 2022 22:58:19 Daniel Golle wrote:
> > On Sun, Sep 04, 2022 at 12:28:24PM -0700, Tony Dinh wrote:
> > > Hi Pali,
> > >
> > > On Sun, Sep 4, 2022 at 2:37 AM Pali Rohár <pali at kernel.org> wrote:
> > > >
> > > > On Saturday 03 September 2022 20:01:45 Tony Dinh wrote:
> > > > > Hi Pali,
> > > > >
> > > > > On Sat, Sep 3, 2022 at 6:29 PM Pali Rohár <pali at kernel.org> wrote:
> > > > > >
> > > > > > Do various small fixup/cleanups and extend test script to boot kernel
> > > > > > image from UBI volume. This test verifies that U-Boot UBI implementation
> > > > > > is working and U-Boot can read volume with bootable kernel code
> > > > > > correctly. And therefore CI prevents UBI breakage.
> > > > > >
> > > > > > Note that U-Boot UBIFS code on ARM is currently somehow broken and
> > > > > > trying to mount UBIFS from UBI volume fails :-( I have already tried to
> > > > > > debug this issue but I have no idea why it is failing.
> > > > >
> > > > > I've recently implemented UBI distro boot on a pair of Kirkwood boards
> > > > > (Pogo V4 and NSA310s) successfully. I created the UBI partition and
> > > > > formatted it in Debian 11.x, Linux kernel 5.19.x. I could let the
> > > > > u-boot distro boot scan the UBI partition to find the boot script
> > > > > boot.scr. And also mount it manually to look at the file system.
> > > >
> > > > Hello! I think you mean UBIFS on UBI, right?
> > >
> > > Yes. UBIFS on UBI.
> > >
> > > >
> > > > > An observation: I cannot mount OpenWrt rootfs in u-boot, since it is
> > > > > an UBIFS volume overlay on squashfs. But creating my own UBIFS volume
> > > > > allowed me to mount it in the u-boot command line. I think squashfs is
> > > > > incomplete in u-boot, at the moment.
> > > >
> > > > UBIFS on squashfs? This looks strange. AFAIK UBIFS (also on linux) works
> > > > only on UBI. I guess you could have squashfs on UBI, but on linux this
> > > > requires mtdblock, hence it is squashfs on mtdblock on UBI.
> > >
> > > I meant that (the rootfs) is a squashfs inside an UBIFS volume. And
> > > the system running with another UBIFS volume overlaid on top of that.
> >
> > Just to clarify: OpenWrt uses squashfs in UBI volumes for the compressed
> > rootfs. In Linux, ubiblock is used to mount them.
>
> That is what I thought. squashfs on ubiblock. IIRC U-Boot does not
> implement neither mtdblock (block device on mtd) nor ubiblock (block
> device on top of ubi volume). So mounting squashfs (which is block based
> filesystem) from ubi volume does not work in u-boot.
>
> I think implementation should not be such hard, this sounds like and
> interesting exercise.
>
> But I'm more interested to figure out why UBIFS does not want to work on
> ARM Omap3 Nokia N900, but works fine on PowerPC Freescale P2020....
>
> > We also usually don't store the kernel in a filesystem but just use a
> > bare UBI volume to directly store the uImage.FIT to be booted, for both
> > simplicity and robustness reasons.
> > On devices with recent enough U-Boot we can use a 'filesystem'-type
> > sub-image of a uImage.FIT for squashfs and mount that in Linux.
> >
> > >
> > > Best,
> > > Tony
> > >
> > > >
> > > > > Best,
> > > > > Tony
> > > > >
> > > > >
> > > > > >  Function
> > > > > > check_lpt_crc in unpack_ltab is failing. Volume is for sure correct and
> > > > > > valid because Linux kernel can successfully mount it. And to make it
> > > > > > more suspicious, U-Boot UBIFS is working fine on big endian powerpc
> > > > > > platform. So UBIFS issue is probably endian or arch specific.
> > > > > > (This is UBIFS related, not UBI related.)
> > > > > >
> > > > > > Pali Rohár (9):
> > > > > >   Nokia RX-51: Remove label copy_kernel_start from lowlevel_init.S
> > > > > >   Nokia RX-51: Do not clear unknown memory in lowlevel_init.S
> > > > > >   Nokia RX-51: Set default SYS_LOAD_ADDR to 0x80008000
> > > > > >   Nokia RX-51: Change UBIFS volume size to 1870 LEBs in test script
> > > > > >   Nokia RX-51: Call bootm in test script only when image is valid
> > > > > >   Nokia RX-51: Fix documentation how to enable UBI support
> > > > > >   Nokia RX-51: Do not set useless ARCH= in test script
> > > > > >   Nokia RX-51: Add comment describing kernel image type into test script
> > > > > >   Nokia RX-51: Add booting from UBI into test script
> > > > > >
> > > > > >  board/nokia/rx51/lowlevel_init.S |  7 +--
> > > > > >  configs/nokia_rx51_defconfig     |  2 +-
> > > > > >  doc/board/nokia/rx51.rst         |  3 +-
> > > > > >  test/nokia_rx51_test.sh          | 97 +++++++++++++++++++++++++-------
> > > > > >  4 files changed, 82 insertions(+), 27 deletions(-)
> > > > > >
> > > > > > --
> > > > > > 2.20.1
> > > > > >