[aarch64-port-dev ] Review Request JDK-8175819: OS name and arch in JMOD files should match the values as in the bundle name (original) (raw)

Bob Vandette bob.vandette at oracle.com
Tue Apr 4 16:47:50 UTC 2017

On Apr 4, 2017, at 12:35 PM, mark.reinhold at oracle.com wrote:

2017/4/4 8:22:50 -0700, aph at redhat.com: On 04/04/17 16:12, mark.reinhold at oracle.com wrote:

The trouble here is that "arm64" and "aarch64" are effectively synonyms for the ISA, but in the JDK we've wound up using them as the names of two different ports.

A JMOD file built for the 64-bit ARM architecture will (one hopes) run equally well on either port. Which name should we use in JMOD files, "arm64" or "aarch64"? My sense is that "arm64" is more immediately understood by developers at large even if "aarch64" is more correct in the eyes of ARM Holdings plc, but I could be wrong. I think that you are wrong. For what it's worth, the Linux distros aren't consistent: Debian-based distros use "arm64", while Red Hat / Fedora seem to prefer "aarch64". The name of the processor architecture is "AArch64". The name of the Linux kernel architecture is "arm64"; the name of all of userspace is "aarch64", on all distros. The kernel is out of step here, for no better reason than Linus Torvalds didn't like "aarch64". Thanks for the background -- I wasn't aware of that. Given that "os.arch" is "aarch64" for both ports, as Bob points out, then we should use "aarch64" in JMOD files as well. This does raise another question, though: Should we use "aarch32" instead of "arm32" for the 32-bit ARM architecture?

32 bit ARM is a bit more challenging since OS vendors sometime encode the architecture version (armv5, armv6, armv7) and endianess into the uname -p output.

aarch32 has special meaning (it’s the arch for running 32-bit arm instructions on an armv8 processor.) and I haven’t seen any use of arm32.

I suggest we stick with arm.

Bob.

- Mark

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