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

[Daniel Golle]

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.

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
> > > >