[PATCH v5 8/8] ARM: defconfig: Add a zx29 defconfig file

[Arnd Bergmann]

On Tue, Apr 21, 2026, at 22:23, Stefan Dösinger wrote:
> This enables existing drivers that already are (UART) or will be (USB,
> GPIO) necessary to operate this board even if they aren't declared in
> the DTS yet.
>
> Signed-off-by: Stefan Dösinger <stefandoesinger at gmail.com>

I'll reply to Linus' comment as well, the defconfigs are generally
not in a great shape across many platforms, so we should come up
with some better policies there.

Either way, the patch description above should at least explain
why you think you need your own defconfig, as we don't normally
take those.

Some comments about the contents of this file:

> +++ b/arch/arm/configs/zx29_defconfig
> @@ -0,0 +1,89 @@
> +CONFIG_SYSVIPC=y
> +CONFIG_BLK_DEV_INITRD=y
> +# CONFIG_RD_BZIP2 is not set
> +# CONFIG_RD_LZMA is not set
> +# CONFIG_RD_XZ is not set
> +# CONFIG_RD_LZ4 is not set
> +CONFIG_EXPERT=y

What is the reason for CONFIG_EXPERT here? Can you avoid this?

> +CONFIG_CMDLINE="console=ttyAMA0 earlyprintk root=/dev/ram rw"

A definconfig should normall not rely on earlyprintk, just add
that when you actually need to debug the super-early boot
stages. With "earlycon" it should pick up the right console
from the stdout path and work almost as early.

> +CONFIG_BINFMT_FLAT=y

Are you actually using flat binaries? I wasn't aware that this
is still possible on MMU-enabled kernels.

> +CONFIG_BLK_DEV_RAM=y
> +CONFIG_BLK_DEV_RAM_COUNT=4

The old ramdisk boot is going away in the future, please use
initramfs instead. This should also save a good amount of RAM.

> +CONFIG_DEVTMPFS=y       # FIXME: This is specific to my initrd. Remove 
> before upstream

stale comment?

> +CONFIG_CONFIG_TMPFS=y

Typo?


       Arnd