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Subjectmmap() versus read() and embedded systems.
  Just my $0.02,

Even if you have memory mapped flash as a file system in an
embedded environment, with romfs, the main problem is the
executable loader: it has to modify (resolve address) of the code
you are executing, so this code has to be copyed first in RAM.
I am not sure that using static library (instead of ELF) solves
completely this problem...

> On Wed, 11 Mar 1998, Michael Lausch wrote:
> ...
> > But the problem is when you are using Linux on embedded systems
> > without any swap (disk) at all. The programs are stored in the FLASH
> > RAM so the cost of reading a page from the executable is almost zero,
> > but using a swap area is impossible (no, we don't have 20 Meg RAM for
> > a RAM swap disk)
>
> Is this paged flash or memory mapped flash? Ideally an embedded system
> would use memory-mapped flash with a filesystem like romfs (? - does it do
> this?) that would provide it's own mmap that just maps in the page, still
> in flash, into the process on nopage. This way your executables take up
> practically no ram under normal circumstances.
> ...
> -ben
----------- etienne.lorrain@ibm.net
-- hdc: irq timeout: status=0xd0 { Busy }
-- ide1: reset: success
----------> I like Linux !

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