dinuxbg / gnuprumcu Goto Github PK

Port or reimplement nolibc for PRU. Add device specs to allow users to choose between the newlib+libglocc and prunolibc. Compare whether there are code size savings for real world firmware projects.

Newlib is standards-compliant proper C library, meant for embedded devices. This is invaluable during regression testing the toolchain. It's also valuable for complex embedded firmware. But for ultra low-resource CPU core meant to be programmed in Assembly, some of its features might be a bit too large. See picolibc for a low-size newlib fork, but it also might be a bit too large for PRU.

For example, in Newlib itoa takes an argument for radix, which dramatically increases the code size if one decides to simply convert an integer to a string. Whereas in nolibc the radix is pragmatically assumed to be 10, thus simplifying complexity and reducing overall code size.

Note that prunolibc would be an optional alternative, not a replacement for newlib. Users should be able to choose between:

• A standards-compliant C library (newlib).
• Not-a-C-library (prunolibc).
• No libraries at all ( -nostdlib -nodefaultlibs toolchain options).