On Thu, Jan 20, 2022 at 01:47:41PM -0700, Simon Glass wrote:
Hi Tom,
On Thu, 20 Jan 2022 at 13:08, Tom Rini trini@konsulko.com wrote:
On Thu, Jan 20, 2022 at 12:56:55PM -0700, Simon Glass wrote:
Hi Tom,
On Thu, 20 Jan 2022 at 11:30, Tom Rini trini@konsulko.com wrote:
On Thu, Jan 20, 2022 at 11:16:35AM -0700, Simon Glass wrote:
Hi Mark,
On Thu, 20 Jan 2022 at 03:29, Mark Kettenis mark.kettenis@xs4all.nl wrote:
> From: Michael Walle michael@walle.cc > Date: Thu, 20 Jan 2022 09:35:44 +0100 > > > The bootdevs have a natural priority, based on the assumed speed of > > the device, so the board would only need to intervene (with an env var > > or a devicetree property) when that is wrong. > > Does this make sense in general? The default boot order for a > board should depend on what is available on board (or on the > carrier board) and what is pluggable. I doubt there can be a sane > default, so almost all boards will have to define its own > boot order anyway.
Please can you be more specific about what you the problem is here? If the board does not have a device then it will not exist in driver model (or will not probe) and it won't have a bootdev (or it won't probe). That seems to be equivalent to me.
So, I'm not sure how much of a problem it is, since the board can still define the default probe order via environment. But pick any random SoC with more than 1 SD/MMC set of lines on the chip. Youboard may put the first as SD slot and second as eMMC and Myboard may do the opposite and both are going to probe in the same order since it's the same chip.
That's what I think Mark is getting at with it not really making sense to just rely on probe order as what to try.
Doesn't the 'non-removable' flag describe this feature of the hardware?
If you don't want to rely on the normal ordering, you can set the boot_targets variable. I'd just like to avoid that being required for 'normal' boards and situations.
I think setting things via the environment to have correct defaults is a must. I mean, yes, OK, if there's some device tree binding that we can use that describes this, sure, that's choice A. But choice B would probably be environment strings. Probe and hope is choice C, or more like last resort, imho.
Well the boot_targets var is implemented in this series.
The question is whether we force platforms to define it, or have a way to handle things gracefully by default.
I think we need to force it to be defined until / unless there's some agreed on standard to provide that information at run time.