This patch adds support for passing boot time information to the Linus kernel using ATAGS when booting on ARM based devices.
I implicitly mentioned this before, here it comes clear again:
Ah, this has been tried before? Sorry, I didn't know that.
I expolained it in my reply to your cover letter, i.e. in the message immediately preceeding the one you replied to here.
So you're telling me off for sending a patch which doesn't agree with something you've said, despite you saying it _after_ I sent the patch?
Sounds sensible. :)
I dislike the idea of adding such infrastructure in an archittecture dependent way, knowing from day one that we cannot use this as is for other architectures, and that the mechanism being used is even going to go away for this architecutre, too.
Please come up with a solution that works for all architectures instead.
So I guess Device Tree it is then.
No. The device tree is for passing hardware information to U-Boot and the kernel. It is NOT intended for carrying things like debug or timing logs. It is not a good idea to misuse such services for things they were not made for nor where they fit.
Okay, got it.
Please use a standard facility, and one designed for such purposes like the Linux log buffer for this purpose. As explained, this has the added benefit that you don't need to change any Linux code. And you can build on the (also existing) show_boot_progress() support in U-Boot, so the extesions should actually be really small and pretty clear.
When you say log buffer, do you mean __log_buf? Doesn't this contain logs used for dmesg; thus won't all this crud end up in a user's dmesg kernel log? Unless there is another log which is used only for the kernel.
Also, wouldn't I then have to write a text parser to process this information? Sounds horrendous. Hopefully, I have missed something and it's actually easier than what I've mentioned.