GPLv3 glibc

GPLv3 glibc

That's interesting, I hadn't realized that. For the benefit of others, the relevant clause:

If you convey an object code work under this section in, or with, or specifically for use in, a User Product, and the conveying occurs as part of a transaction in which the right of possession and use of the User Product is transferred to the recipient in perpetuity or for a fixed term (regardless of how the transaction is characterized), the Corresponding Source conveyed under this section must be accompanied by the Installation Information. But this requirement does not apply if neither you nor any third party retains the ability to install modified object code on the User Product (for example, the work has been installed in ROM).

Nowadays, Flash is cheaper than ROM for all but the smallest microcontrollers (like 8 bit
size). GlibC is huge, so it doesn't make sense to put it in ROM. If it's in flash, they're
going to leave themselves a way to write it (even if it's just thru JTAG). Therefore it's
unlikely anyone distributes a completely non-writable GlibC (or even Linux kernel for that
matter).