[Gta04-owner] QtMoko v49

[Dr. H. Nikolaus Schaller]

Hi Neil,

Am 19.11.2012 um 21:54 schrieb Neil Jerram:

> "Dr. H. Nikolaus Schaller" <hns at goldelico.com> writes:
> 
>> But I think others should also state their opinions if they need the gta04-init
>> features as part of QtMoko or a separate tool and how it should work.
> 
> I'd just say that I don't like any solution that involves having to
> press AUX within certain precise time ranges without any explicit
> prompting about that on the screen.

There is no specific timing.

Just press AUX before the power button and leave it pressed until
you see the graphical u-boot menu. Then, release the button (or leave
it pressed as long as you like :)

> 
> It sounds to me like Nikolaus's and Radek's schemes both have important
> merits, so I hope we can get the best of both of them!  In particular:
> 
> 1. it's very much desirable - for the sanity of this mailing list - if
>   GTA04s can be set up with an initial system that is almost impossible
>   to mess up

I think the current u-boot system has reached this goal.

> 
> 2. it will be a really nice feature to have multiple distributions
>   installed and to boot easily between them.
> 
> For (2), the current gta04-init scheme is nice but I'm not sure it's
> what people would expect.  Probably people are more familiar with
> selecting the OS that they want when they boot up, as that is what
> happens on laptops and desktops.  Also it is QtMoko-specific, and so
> analogous work would be needed in all other distributions, if that was
> our preferred booting design.  Whereas surely a bootloader-based
> solution would only need implementing once?

Yes, this is why I have implemented the new u-boot loader.

> 
> What seems natural to me would be:
> 
> - Always use the bootloader in NAND.  (Except for whatever we might need
>  for recovery from that becoming corrupt.)

Yes, done.

It is used unless you have one on SD (e.g. for recovery, upgrades etc.) but this
is a special case.

> 
> - Choice 1: NAND kernel + NAND rootfs.

Yes, this is button "NAND" in AUX menu.

And, it is the default if no SD card is installed. Or no kernel found on SD card
(it may be desirable to have a "data only" SD).

> 
> - Choice 2..N: Each partition on the SD card that has /boot/uImage* and
>  a recognised rootfs type.

Yes, is what the u-boot boot.scr does if you choose SD:1 to SD:4. It scans for
/boot/uImage and /boot/bootargs.scr (or in root of a FAT partition).

> 
> - Bootloader should present those choices in a menu and use AUX/Power to

These choices are presented in the AUX menu and you just tap the button of
your preferred choice.

No need to cycle through choices.

>  cycle through them.  Boots if no movement for 5s.  Remembers and
>  defaults to whichever choice was booted last time.

Yes, is remembered.

> 
> - Bonus: Allow each partition to specify its title and icon by files in /boot.

Hm. This requires a GUI system for the boot loader. U-boot can't display text.

> 
> (I can't see that NAND kernel + SD rootfs would ever make sense.)

There is a rare exception if there is a different display connected to the
GTA04 and only the NAND kernel knows the right driver. But this option
comes for free by the logic of the latest boot.scr and does not need to be used...

> 
> (OK, I guess that wasn't "just" after all...)

The new boot.scr system is set up in a way that you don't even need to
know about the AUX menu unless you want to switch between different distros
on a single SD card.

If you have them on different cards, just swap them and they will boot.
If you have none, NAND will boot. Without any further setup. Is there
a simpler scheme?

Maybe the main problem is that the new boot system is lacking a complete
and easily understandable description.

There are already some words in the latest GTA04A4 manual.

BR,
Nikolaus