Marco Colombo wrote:
>
> On Tue, 21 Mar 2000, Helge Hafting wrote:
> > Having enough RAM is fine for a pc. An embedded device running linux
> > will likely
> > be mass-produced with the minimum amount of RAM though.
>
> And no MMU and no swap space. They will never go OOS. No paging.
> No processes killer. And why processes? Why a scheduler?
>
> Besides that, why any embedded device should be optimized for high
> multitasking - multiuser - general purpose workloads? That's what
> "overcommitting" is for. That's what (vanilla) Linux is designed for.
> Many parts of it are not well suited for embedded systems. They are not
> designed for them.
Don't underestimate embedded devices, some of them have uses for mmu,
paging, and multiple processes.
A printer controller may use a disk drive for storing large print
jobs as well as repeat jobs such as standard forms and custom
fonts. I have seen office machines that combine telefax, scanner,
printer, copying and modem in one box. (Great idea, every part
has several uses) This is complex and can use a multiprocess
environment - you don't want fax reception or a dialup line
to stop just because some clerk copies a few letters for the
snail-mail archive.
A dedicated gaming machine will want to support today's
multithreaded games, and it need the ability
to run all kinds of games, not merely a particular one.
Both this and the advanced printer can use networking.
With networking and storage devices
you want the MMU to protect the os from app bugs.
And then there are various kinds of devices that used to be simple but
now they want to have a web interface. Linux + an open source webserver
is a cheap way to get that, and you probably want the core functionality
protected from the web stuff.
Helge Hafting
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This archive was generated by hypermail 2b29 : Thu Mar 23 2000 - 21:00:35 EST