RE: [PATCH] configs: layerscape: Disable the EFI_LOADER feature

["Z.Q. Hou" <zhiqiang.hou@nxp.com>]

Hi Tom,

> -----Original Message-----
> From: Tom Rini <trini@konsulko.com>
> Sent: 2021年7月26日 20:29
> To: Z.Q. Hou <zhiqiang.hou@nxp.com>
> Cc: Michael Walle <michael@walle.cc>; Heinrich Schuchardt
> <xypron.glpk@gmx.de>; u-boot@lists.denx.de; Priyanka Jain
> <priyanka.jain@nxp.com>
> Subject: Re: [PATCH] configs: layerscape: Disable the EFI_LOADER feature
> 
> On Mon, Jul 26, 2021 at 07:37:53AM +0000, Z.Q. Hou wrote:
> > Hi Micheal,
> >
> > > -----Original Message-----
> > > From: Michael Walle <michael@walle.cc>
> > > Sent: 2021年7月26日 15:13
> > > To: Z.Q. Hou <zhiqiang.hou@nxp.com>
> > > Cc: Tom Rini <trini@konsulko.com>; Heinrich Schuchardt
> > > <xypron.glpk@gmx.de>; u-boot@lists.denx.de; Priyanka Jain
> > > <priyanka.jain@nxp.com>
> > > Subject: Re: [PATCH] configs: layerscape: Disable the EFI_LOADER
> > > feature
> > >
> > > Am 2021-07-26 09:01, schrieb Z.Q. Hou:
> > > > Hi Michael,
> > > >
> > > >> -----Original Message-----
> > > >> From: Michael Walle <michael@walle.cc>
> > > >> Sent: 2021年7月23日 1:01
> > > >> To: Tom Rini <trini@konsulko.com>
> > > >> Cc: Z.Q. Hou <zhiqiang.hou@nxp.com>; Heinrich Schuchardt
> > > >> <xypron.glpk@gmx.de>; u-boot@lists.denx.de; Priyanka Jain
> > > >> <priyanka.jain@nxp.com>
> > > >> Subject: Re: [PATCH] configs: layerscape: Disable the EFI_LOADER
> > > >> feature
> > > >>
> > > >> Am 2021-07-22 17:26, schrieb Tom Rini:
> > > >> > On Thu, Jul 22, 2021 at 02:25:59PM +0800, Zhiqiang Hou wrote:
> > > >> >
> > > >> >> From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
> > > >> >>
> > > >> >> The feature BOOTENV_SHARED_EFI is not supported on layerscape
> > > >> boards,
> > > >> >> it didn't result kernel boot crash previously since there
> > > >> >> isn't the efi/boot/"BOOTEFI_NAME" and it skip calling of
> 'boot_efi_binary'.
> > > >> >>
> > > >> >> But since the commit f3866909e350 ("distro_bootcmd: call EFI
> > > >> >> bootmgr even without having /EFI/boot"), it will cause kernel
> > > >> >> boot crash as there isn't a valid fdt_addr and it finially
> > > >> >> uses the device tree blob of U-Boot and further cause errors.
> > > >> >>
> > > >> >> As this feature is enabled by default for armv7 and armv8, so
> > > >> >> disable it explicitly to avoid calling the 'scan_dev_for_efi'.
> > > >> >
> > > >> > I'm not thrilled with this.  Why isn't the solution to get and
> > > >> > keep in sync the device trees, so that the tree U-Boot has is
> > > >> > valid for the kernel?  I'm also open to discussing f3866909e350
> > > >> > more.  But I'm really opposed to disabling EFI_LOADER on modern
> > > >> > platforms as that will make adoption of U-Boot in device harder I
> feel.
> > > >>
> > > >> I don't know whats going on with the NXP boards, but the sl28 is
> > > >> a layerscape board it is working pretty well with EFI boot.
> > > >
> > > > Do you mean the EFI boot work well on sl28?
> > > This, for example, I can boot the debian installer out-of-the-box,
> > > given that the fdtfile variable is set correctly.
> >
> > Oh, we are talking on different case.
> >
> > >
> > > > Or the EFI boot doesn't break other boot ways?
> > > >
> > > > In my case, there are 4 MMC partitions and a boot script with boot
> > > > images in the 2nd partition, while nothing in the 1st partition.
> > > > So the expected boot flow is the 'bootcmd_mmc0' scan the 1st
> > > > partition and find it's not bootable and then the 2nd partition
> > > > and boot with the script. But actually the 'scan_dev_for_efi' got
> > > > problem when scan the 1st partition, as the u-boot DTB is used in
> > > > 'bootefi bootmgr' and result in some error related to the DTB.
> > >
> > > As mentioned in the other mail, I'm not sure why "bootefi bootmgr"
> > > does something at all, because AFAIK it needs the BootOrder/BootNext
> > > variables. Heinrich, please correct me if I'm wrong.
> >
> > I'm not familiar with EFI boot, In this case, the 'scan_dev_for_efi' calls 'run
> boot_efi_bootmgr' then 'bootefi bootmgr', seems it doesn't check if the
> needed components exist.
> > Is the cmd 'scan_dev_for_efi' wrong?
> 
> I'll let Heinrich comment on this part.
> 
> > > > Actually, if give a readable but invalid 'fdt_addr' in env, the
> > > > EFI boot can also be skipped during the scan of the 1st partition.
> > > > Actually on some Layerscape boards the provided env 'fdt_addr'
> > > > with a non-readable address, and on other boards a readable
> > > > 'fdt_addr'. Seems the patch author copy them from somewhere but
> > > > didn't cause issue that time. But this is just a workaround, the
> > > > EFI boot should not cause problem during the scan phase when there
> > > > isn't needed components in one of these partitions.
> > >
> > > What exactly is going wrong? Is linux booting at all? Or does the
> > > bootloader abort?
> >
> > Pasted the log below, the direct cause seems the u-boot DTB doesn't have
> /cpus node.
> >
> > => run bootcmd_mmc0
> > switch to partitions #0, OK
> > mmc0 is current device
> > Scanning mmc 0:1...
> > libfdt fdt_check_header(): FDT_ERR_BADMAGIC Scanning disk
> > esdhc@1560000.blk...
> > Found 5 disks
> > No EFI system partition
> > couldn't find /cpus
> > "Synchronous Abort" handler, esr 0x96000006
> > elr: 0000000082004a6c lr : 0000000082004a30 (reloc)
> > elr: 00000000fbd25a6c lr : 00000000fbd25a30
> > x0 : 0000000087f00a88 x1 : 000000001cfbfd5e
> > x2 : efbeaddeefbeadde x3 : 00000000efbeadde
> > x4 : 00000000fffffffc x5 : 0000000087f037d2
> > x6 : 0000000000000a58 x7 : 0000000000000003
> > x8 : 0000000087f00000 x9 : 0000000000000008
> > x10: 0000000000000a44 x11: 00000000fbc17c6c
> > x12: 00000000000009e4 x13: 0000000000000000
> > x14: 0000000087f00000 x15: 00000000fbc180d8
> > x16: 00000000fbd742d0 x17: 0000000000000000
> > x18: 00000000fbc1cdb0 x19: 00000000000009e4
> > x20: 0000000087f00000 x21: 00000000fbdb3404
> > x22: 00000000fbdb4a97 x23: 0000000000000018
> > x24: 00000000fbde5d44 x25: 0000000000000000
> > x26: 0000000000000000 x27: 0000000000000000
> > x28: 00000000fbc5ba60 x29: 00000000fbc17d30
> >
> > Code: a94153f3 a9425bf5 a8c47bfd d65f03c0 (b8617803) Resetting CPU ...
> >
> >
> > >
> > > And why don't you fix the fdt_addr then? Shouldn't it be unset if there is
> no
> > > actual device tree present in a ROM section? (I don't say there isn't
> another
> > > underlying problem when you use an invalid fdt_addr).
> >
> > The problem shown in above log is triggered when unset the fdt_addr.
> 
> OK, so that shows a problem to fix.  If there's not a valid device tree
> found, that error needs to be handled and not ignored.

Drop this patch if the problem can be fix.

> 
> > If it not unset, the SError is triggered when to check the magic of the fdt
> header.
> 
> Sorry, which is the SError?

I didn't paste that error log.

Thanks,
Zhiqiang

> 
> --
> Tom