Re: [PATCH 3/5] arm: mvebu: turris_omnia: Always enable MMC, SCSI and USB boot targets

Pali Rohár
2022-04-08T09:00:38Z

On Wednesday 06 April 2022 21:31:18 Marek Behún wrote:
> On Wed, 6 Apr 2022 11:39:34 +0200
> Pali Rohár <pali@kernel.org> wrote:
>
> > U-Boot for Turris Omnia is always compiled with MMC, SCSI and USB support,
> > so always enable macros for booting from these devices.
>
> This is not true. Attaching config where scsi is disabled.
>
> If we want to enforce MMC, SCSI and USB, we should add
> select MMC
> and others to Kconfig under TURRIS_OMNIA. But do we want to enfore
> these?
>
> Marek

IIRC macro BOOT_TARGET_DEVICES just defines default values for ENV. So
in default ENV would be macros for booting from SCSI, MMC and USB
targets. Which means that if you call saveenv on U-Boot compiled with
all these options and then replace U-Boot with the one without e.g. MMC
support, it does not replace env variables for MMC booting.

Anyway, does not defining e.g. SCSI booting env variables on U-Boot
without SCSI support result in the same state as defining SCSI booting
env variables on U-Boot with SCSI support with disconnected SCSI
controllers or disks? In both cases there would be no SCSI suitable boot
device.