[PATCH] configs: layerscape: Disable the EFI_LOADER feature

Mon Jul 26 14:28:36 CEST 2021

On Mon, Jul 26, 2021 at 07:37:53AM +0000, Z.Q. Hou wrote:
> Hi Micheal,
> 
> > -----Original Message-----
> > From: Michael Walle <michael at walle.cc>
> > Sent: 2021年7月26日 15:13
> > To: Z.Q. Hou <zhiqiang.hou at nxp.com>
> > Cc: Tom Rini <trini at konsulko.com>; Heinrich Schuchardt
> > <xypron.glpk at gmx.de>; u-boot at lists.denx.de; Priyanka Jain
> > <priyanka.jain at 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 at walle.cc>
> > >> Sent: 2021年7月23日 1:01
> > >> To: Tom Rini <trini at konsulko.com>
> > >> Cc: Z.Q. Hou <zhiqiang.hou at nxp.com>; Heinrich Schuchardt
> > >> <xypron.glpk at gmx.de>; u-boot at lists.denx.de; Priyanka Jain
> > >> <priyanka.jain at 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 at 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 at 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.  

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

Sorry, which is the SError?

-- 
Tom
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