[Vm-dev] oops to zero
bert at freudenbergs.de
Fri Oct 5 07:52:16 UTC 2007
On Oct 5, 2007, at 5:05 , Keith Hodges wrote:
> John M McIntosh wrote:
>> (a) The OLPC actually uses a compressed file system already,
>> because of that Published Sophie Books for the OLPC use a zipped
>> file with no compression. The zipped file will live in the journal
>> at some point.
>> (b) Does setting oops values back to start of zero actually make
>> it more compressable, versus say a start value of 0x00004000?
> We are not actually setting the oops back to zero, but back
> relative-to-zero, They are just numbers, just different numbers. I
> would not imagine that this has any effect upon the compressibility
> of any single image. However diff algorithms working with two or
> more images are more likely to see that much of a saved image is
> the same as the last time it was saved. From the little I know it
> seems that the OLPC file system (as well as mercurial binary
> storage) is designed with this in mind.
> Indeed you make a good point, if we can pick a good number that
> runtimes can use without traversing the image then great. What
> number should it be?
I don't think any OS (except for DOS maybe) would guarantee you a
specific start address.
> Since OLPC applications have a virtual linux box to themselves can
> we just pick a number that suits us/them?
I wouldn't think so ... but it is an interesting idea. I will ask the
- Bert -
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