[U-Boot] Multiple device support - none at all?

[Detlev Zundel]

Hello ksi (so I'll leave it at that),

> First of all, there are several bootable devices on a motherboard itself.
> These days almost every motherboard has PATA and some kind of SATA RAID
> controller onboard. Then, it can usually boot off of USB while having USB
> keyboard/mouse. As for add-on devices, it usually CAN boot off of those
> devices. They have their own BIOS for that that gets attached to the
> motherboard's one when it initializes and those devices are added to the
> boot table.

It may come as a surprise to you, but I actually also use such system :)

What I wanted to say is that your blatant "it allows me to choose from
which device to boot from" does not coincide with my experiences in real
life.  Moreover what you call "to boot from" is in the BIOS world the
transfer of usually one block followed by a jump.  I have yet to see a
BIOS booting Linux in a flexible way.  This is hardly comparably to the
support (just think filesystems) that we have for ages in U-Boot.  

But actually I think that this is not news to most people on the ML so
I'll stop here.

>> As Jerry pointed out - booting embedded hardware used to be a comparably
>> simple operation ;)
>
> There is a whole world beyond that keyhole... Embedded devices yes, but
> there are other boards that don't fall in that category. My current MPC8548
> based board is not an embedded one, it is full-blown mATX motherboard with
> several USB controllers, PATA, SATA, Video Capture, VGA/LCD controller,
> PCI-X/PCI/PCIe connectors etc.

Yes, and again, you may notice that U-Boot was meant for "embedded
devices" so the "impedance mismatch" you now realize for "full-blown
motherboards" was kind of to be expected...

> ******************************************************************
> *  KSI at home    KOI8 Net  < >  The impossible we do immediately.  *
> *  Las Vegas   NV, USA   < >  Miracles require 24-hour notice.   *
> ******************************************************************

Miracles in 24 hours?  Ok, I'm looking forward to a device model
implementation tomorrow evening then ;)

Cheers
  Detlev

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