"Canonical" way of changing the size of off_t, ino_t, ...

Stefan Heinzmann stefan_heinzmann@gmx.de
Sun Apr 27 16:27:46 GMT 2025


Hello list,

I am using the newlib build for arm-none-eabi from ArchLinux for 
simplicity, but I now need to change the size of some predefined POSIX 
types. I wasn't able to find clear instructions how to do this properly, 
hence my question here.

The default sizes of offs_t, ino_t, and possibly other types are too 
small for my use. Ideally I would like to customize the newlib build in 
a way that doesn't require the user builds to define anything, i.e. that 
the correct sizes are picked up from the newlib headers automatically. 
How do I do that? Are there configuration options I can use when 
building newlib? Do I have to patch the source, and if so, where?

I note that there is support for off64_t and the respective functions, 
but I would prefer to have off_t defined as 64-bit, in a way similar to 
_FILE_OFFSET_BITS=64 in glibc.

Similarly, how do I make ino_t larger? What about dev_t, and other POSIX 
types?

Thanks for your help!

Cheers
Stefan



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