[mkgmap-dev] EU map too big?

Fri May 15 11:02:28 BST 2015

Hi Minko,

I don't know much about the reason for this 16MB limit. I found this in
imgformat-1.0.pdf:
"This definition implies that an IMG file can never have more than 65,535
blocks, but
the use of large block sizes (2048, 4096, etc…) allow the IMG file to hold
several gigabytes of
data. The only practical limit on IMG file size seems to be the use of
32-bit integers for file
offsets, which imposes a hard limit of 4 GB.
Large sub-files, those with more than 240 blocks of data, are spanned across
multiple FAT
blocks with each sub-file part numbered in a 32-bit integer at offset 0x10.
File size is only
present in the first of these (part 0x0000)."

65535 * 256 ~ 16BG, so I assume that this is the reason. I see files which
use a different
blocksize, so maybe this limit makes no more sense.

@Steve: Can you have a look at this, please?

Gerd

ligfietser wrote
> Thanks Gerd, 
> I have now updated and uploaded the Europe map in case you'll make another
> bike trip ;-) 
> http://www.openfietsmap.nl/downloads/europe 
> 
> BTW Is 16 Mb still the limit for the overview map? 
> 
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