[links] DirectFB font rendering

[Mikulas Patocka]

> > I run Links on embedded linux without swap, and the memory on board is 
> > only about 58MB. :(
> 
> 114MB shouldn't go into the semiconductor memory, but into the virtual 
> memory. It's like several GB. Mikulas, can you comment on this?

If you have CPU with paging, it should be demand-paged --- i.e. it loads 
only those pages that it requires and releases them if free memory goes 
low.

If you have CPU without paging (*-nommu Linux kernels), it will load the 
whole binary, there is no help for it.

You can change in font_include.c unsigned char font_data and struct letter 
letter_data to const unsigned char font_data and const struct letter 
letter_data to see if it helps (with some weird dynamic loaders it may 
help), but if your CPU has no paging, there is no improvement possible.

Mikulas