3 ms·
Custom extensions go into custom space. RISC-V cares about its trademarks; a non-compliant core would not be allowed to use them.
by snvzz 3y ago
Custom extensions go into custom space.
RISC-V cares about its trademarks; a non-compliant core would not be allowed to use them.
- saagarjha 3y agoThat's not what I mean. I'm saying that if someone makes a program that uses custom extensions, they might label it as "RISC-V" but it doesn't actually work on my machine. Of course other ISAs also have extensions, but they are standard and programs typically check for them before using them. Does RISC-V have a way of looking for which extensions are available? Especially if there are a lot of entities that can implement them?
- snvzz 3y agoThe ISA spec does indeed have a sane, easy to understand method. The rest is a software problem. I know that e.g. Linux exposes the required information about the CPU's ISA via a dedicated syscall. I do not know whether there's some ELF header or the like.
- camel-cdr 3y agoIt does? Isn't it read the device tree isa string, the csr bits for the most common things, or catch the trap on illegal instruction?