SmackerNews

Disambiguating Arm, Arm ARM, ARMv9, ARM9, ARM64, AArch64, A64, A78, ...

nickdesaulniers.github.io/blog/2023/03/10/disambiguating-arm

313 points · 87 comments · 3 years ago · matt_d

nickdesaulniers.github.io/blog

electroly3 years ago
So the ARM Architectural Reference Manual (the Arm ARM) defines the three architectural profiles: A, R, and M. I'm not even mad, that's amazing.
userbinator3 years ago
Apple platforms diverge from Arm’s ABI in specific ways.
...and so does Microsoft with its ARM64EC ABI:
https://learn.microsoft.com/en-us/cpp/build/arm64ec-windows-...
I've always thought it odd that a CPU manufacturer would specify an ABI, since that seems to imply preference towards certain programming languages and techniques which may or may not be ideal in all cases; Intel certainly didn't.
AdamH121133 years ago
Good old ARM naming schemes. I remember some amusement when I worked at TI and my team went from working on an ARM7-based microcontroller to an ARMv7-based microcontroller. (The ARM7 was an ARMv4 CPU, naturally.)
schemescape3 years ago
Timely, but not quite what I needed (unless I missed something in the article—pretty likely). I just spent a bunch of time setting up a Raspberry Pi 1 B with Alpine Linux, and it was surprisingly difficult to find the right strings of gibberish to get everything set up.
The Alpine packages are “armhf” and the last 2 letters I think mean it has hardware floating point support.
The kernel is armv6l and I still don’t know what the last letter is for.
Cross-compiling for it can be annoying, but I seem to be able to pass the CPU name directly (I don’t remember it off-hand, but it’s more easily Google-able) to get things to build properly.
I don’t really have a point, just venting…
drcongo3 years ago
I think I'm more confused now than I was before.
zeroimpl3 years ago
So when I run “uname -m” on Mac it says “arm64”, but running it in a docker container on the Mac it says “aarch64”. Doesn’t seem like everybody is in agreement.
ghotli3 years ago
This is useful context but seems incomplete without direct links to the gcc docs for both arm and aarch64.
For your perusal. :)
https://gcc.gnu.org/onlinedocs/gcc-12.2.0/gcc/ARM-Options.ht...
https://gcc.gnu.org/onlinedocs/gcc-12.2.0/gcc/AArch64-Option...
anonymousDan3 years ago
This has cleared up a lot of confusion for me!
Slightly tangential, but can people recommend a good site for finding hardware available to purchase for specific ARM versions? In particular, when hardware implementing a new ARM version (e.g. 8.5 or 9) becomes available, where should I be keeping an eye on?
Alternatively, what manufacturers are usually the first to produce new ARM hardware?
fl0ps3 years ago
Bookmarked (and appreciated!) solely to let me be lazy and send a link instead of repeating the same speech to other devs.
yakubin3 years ago
What’s an execution state? From my reading of this post, it doesn’t seem to be an architecture.
s-wilson-x10-63 years ago
don’t forget arm26
otabdeveloper43 years ago
Having read all that I am now even more confused and ambiguated.
Technical writing is hard.
orthoxerox3 years ago
And they say it's Microsoft that is bad at naming their products.
DeathArrow3 years ago
I though ARM is an acronym of ARM Rephrases Meanings.
askvictor3 years ago
Why would someone name it ARM64 when it looks so similar to AMD64. I'm sure that has caused some confusion or things to break (or will do so at some point). Naming things is a usability issue.

news.ycombinator.com/item?id=35100297

SmackerNews

A placeholder title for loading skeleton

example.com/path/to/article

000 points · username · 0 hours ago

example.com

SmackerNews

Disambiguating Arm, Arm ARM, ARMv9, ARM9, ARM64, AArch64, A64, A78, ...

nickdesaulniers.github.io/blog/2023/03/10/disambiguating-arm

313 points · 87 comments · 3 years ago · matt_d

nickdesaulniers.github.io/blog

electroly3 years ago
So the ARM Architectural Reference Manual (the Arm ARM) defines the three architectural profiles: A, R, and M. I'm not even mad, that's amazing.
userbinator3 years ago
Apple platforms diverge from Arm’s ABI in specific ways.
...and so does Microsoft with its ARM64EC ABI:
https://learn.microsoft.com/en-us/cpp/build/arm64ec-windows-...
I've always thought it odd that a CPU manufacturer would specify an ABI, since that seems to imply preference towards certain programming languages and techniques which may or may not be ideal in all cases; Intel certainly didn't.
AdamH121133 years ago
Good old ARM naming schemes. I remember some amusement when I worked at TI and my team went from working on an ARM7-based microcontroller to an ARMv7-based microcontroller. (The ARM7 was an ARMv4 CPU, naturally.)
schemescape3 years ago
Timely, but not quite what I needed (unless I missed something in the article—pretty likely). I just spent a bunch of time setting up a Raspberry Pi 1 B with Alpine Linux, and it was surprisingly difficult to find the right strings of gibberish to get everything set up.
The Alpine packages are “armhf” and the last 2 letters I think mean it has hardware floating point support.
The kernel is armv6l and I still don’t know what the last letter is for.
Cross-compiling for it can be annoying, but I seem to be able to pass the CPU name directly (I don’t remember it off-hand, but it’s more easily Google-able) to get things to build properly.
I don’t really have a point, just venting…
drcongo3 years ago
I think I'm more confused now than I was before.
zeroimpl3 years ago
So when I run “uname -m” on Mac it says “arm64”, but running it in a docker container on the Mac it says “aarch64”. Doesn’t seem like everybody is in agreement.
ghotli3 years ago
This is useful context but seems incomplete without direct links to the gcc docs for both arm and aarch64.
For your perusal. :)
https://gcc.gnu.org/onlinedocs/gcc-12.2.0/gcc/ARM-Options.ht...
https://gcc.gnu.org/onlinedocs/gcc-12.2.0/gcc/AArch64-Option...
anonymousDan3 years ago
This has cleared up a lot of confusion for me!
Slightly tangential, but can people recommend a good site for finding hardware available to purchase for specific ARM versions? In particular, when hardware implementing a new ARM version (e.g. 8.5 or 9) becomes available, where should I be keeping an eye on?
Alternatively, what manufacturers are usually the first to produce new ARM hardware?
fl0ps3 years ago
Bookmarked (and appreciated!) solely to let me be lazy and send a link instead of repeating the same speech to other devs.
yakubin3 years ago
What’s an execution state? From my reading of this post, it doesn’t seem to be an architecture.
s-wilson-x10-63 years ago
don’t forget arm26
otabdeveloper43 years ago
Having read all that I am now even more confused and ambiguated.
Technical writing is hard.
orthoxerox3 years ago
And they say it's Microsoft that is bad at naming their products.
DeathArrow3 years ago
I though ARM is an acronym of ARM Rephrases Meanings.
askvictor3 years ago
Why would someone name it ARM64 when it looks so similar to AMD64. I'm sure that has caused some confusion or things to break (or will do so at some point). Naming things is a usability issue.

news.ycombinator.com/item?id=35100297