[PATCH] configs: layerscape: Disable the EFI_LOADER feature

[Michael Walle]

Am 2021-07-22 19:02, schrieb Tom Rini:
> On Thu, Jul 22, 2021 at 07:00:31PM +0200, Michael Walle wrote:
>> 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.
>> 
>> So why don't you fix the root cause instead of disabling this
>> feature?
> 
> Having thought a bit more on this, if the U-Boot run-time DTB causes 
> the
> kernel to fail that would seem to be a rather big failing on the whole
> "DTB is ABI" thing, would it not?

The u-boot dtb isn't really compatible with the kernel dtb, is it? Eg.
the DSA binding is different, the USB binding (might be) is different, 
eg.
I tried to get the dwc3 driver to work on the LS1028A and it seems that
u-boot (intentionally) needs subnodes to the actual device node in the
DTB, just to load a usb peripheral or usb host mode driver for the
subnode. Thus even, that is an implementation detail which should have
never ended up in the DTB. The enetc binding is different AFAIK.

TBH, I'm suprised that the u-boot dtb is passed to linux if there is
no other available.

> I'm not saying that's not what's
> happening, rather I'm noting that it's not supposed to happen and old
> DTB + new kernel should work.

-michael