4 ms·

Well, wasn't the 601 a bit different than the 603/604 in instruction sets? I seem to remember there were some difference from the more refined, later chips.

Zenst 6y ago
Yes, some of the ISA was still be standardised so wasn't until the later chips that got ratified, so some nuances, though at hand none I can recall. https://en.wikipedia.org/wiki/PowerPC_600#PowerPC_601 https://en.wikipedia.org/wiki/PowerPC_600#PowerPC_601 covers this aspect at least. Also does seem that 32bit support is on the way out, slowly but surely. Though 32bit will be around for a while in some flavour or another, much like IPv4, it just hangs in there working away.
- monocasa 6y ago
  > Also does seem that 32bit support is on the way out, slowly but surely. I would be very, very surprised if 32bit support was on it's way out any time soon. E500 cores are basically 603e, and they don't really seem to be going anywhere. Killing off the early non standard core that no one has used in decades anymore is one thing, but 32bit PowerPC support in general sounds like crazy town to me.
  - happycube 6y ago
    e500mc is. e500v1 and v2 aren't even user-space compatible because Ruiz-era Motorola was cheap and wanted SMD w/o Altivec, so they replaced the FPU...
    - monocasa 6y ago
      They're not user space compatible, but they're very, very similar uarchs as you can tell from the supervisor SPRs.
    - cbmuser 6y ago
      > e500v1 and v2 aren't even user-space compatible because Ruiz-era Motorola was cheap and wanted SMD w/o Altivec, so they replaced the FPU... Both run the standard Debian powerpc port with a kernel with FPU emulation enabled. There used to be a powerpcspe in Debian which I maintained where even Rust worked after I added target support to the Rust compiler (and one very talented FreeBSD developer improved the LLVM backend). However, GCC upstream decided to kill off the powerpcspe port for GCC 9, so we had to drop it in Debian.
- jeffbee 6y ago
  32-bit hardware is still widely produced and deployed. Some desktop-focused distros have dropped 32-bit x86 support but I'm sure the kernel and toolchain will support 32-bit platforms for the foreseeable future. Certainly 32-bit ARM hasn't gone anywhere, and you can't swing a patch cable without hitting a SuperH.
  - Teknoman117 6y ago
    You also have the kernel recently adopting both 32 and 64 bit RISC-V.
- cbmuser 6y ago
  > Also does seem that 32bit support is on the way out, slowly but surely. Nah, we're currently even adding LLVM/Rust support for m68k, so don't worry, 32-bit support isn't going anywhere soon.
  - rbanffy 6y ago
    Compiling Rust on a m68k machine would demand some patience.
    - monocasa 6y ago
      I imagine most would be using it as a cross compiler.
      - rbanffy 6y ago
        Hopefully.
      - kjs3 6y ago
        That's what I'm counting on (looks at his 68030 homebrew board fondly).
theduncan 6y ago
from the article. "The PowerPC 601 code also requires special handling from the rest of the PowerPC 6xx support still within the kernel, thus it's a maintenance burden." so yes some differences.
mrpippy 6y ago
The 601 had support for some POWER instructions that weren’t part of the PPC ISA and weren’t supported by later chips, I know Apple’s developer notes for these machines mentioned that you had to avoid those.

Zenst 6y ago

Yes, some of the ISA was still be standardised so wasn't until the later chips that got ratified, so some nuances, though at hand none I can recall. https://en.wikipedia.org/wiki/PowerPC_600#PowerPC_601 https://en.wikipedia.org/wiki/PowerPC_600#PowerPC_601 covers this aspect at least. Also does seem that 32bit support is on the way out, slowly but surely. Though 32bit will be around for a while in some flavour or another, much like IPv4, it just hangs in there working away.

monocasa 6y ago
> Also does seem that 32bit support is on the way out, slowly but surely. I would be very, very surprised if 32bit support was on it's way out any time soon. E500 cores are basically 603e, and they don't really seem to be going anywhere. Killing off the early non standard core that no one has used in decades anymore is one thing, but 32bit PowerPC support in general sounds like crazy town to me.
- happycube 6y ago
  e500mc is. e500v1 and v2 aren't even user-space compatible because Ruiz-era Motorola was cheap and wanted SMD w/o Altivec, so they replaced the FPU...
  - monocasa 6y ago
    They're not user space compatible, but they're very, very similar uarchs as you can tell from the supervisor SPRs.
  - cbmuser 6y ago
    > e500v1 and v2 aren't even user-space compatible because Ruiz-era Motorola was cheap and wanted SMD w/o Altivec, so they replaced the FPU... Both run the standard Debian powerpc port with a kernel with FPU emulation enabled. There used to be a powerpcspe in Debian which I maintained where even Rust worked after I added target support to the Rust compiler (and one very talented FreeBSD developer improved the LLVM backend). However, GCC upstream decided to kill off the powerpcspe port for GCC 9, so we had to drop it in Debian.
jeffbee 6y ago
32-bit hardware is still widely produced and deployed. Some desktop-focused distros have dropped 32-bit x86 support but I'm sure the kernel and toolchain will support 32-bit platforms for the foreseeable future. Certainly 32-bit ARM hasn't gone anywhere, and you can't swing a patch cable without hitting a SuperH.
- Teknoman117 6y ago
  You also have the kernel recently adopting both 32 and 64 bit RISC-V.
cbmuser 6y ago
> Also does seem that 32bit support is on the way out, slowly but surely. Nah, we're currently even adding LLVM/Rust support for m68k, so don't worry, 32-bit support isn't going anywhere soon.
- rbanffy 6y ago
  Compiling Rust on a m68k machine would demand some patience.
  - monocasa 6y ago
    I imagine most would be using it as a cross compiler.
    - rbanffy 6y ago
      Hopefully.
    - kjs3 6y ago
      That's what I'm counting on (looks at his 68030 homebrew board fondly).

theduncan 6y ago

from the article. "The PowerPC 601 code also requires special handling from the rest of the PowerPC 6xx support still within the kernel, thus it's a maintenance burden." so yes some differences.

mrpippy 6y ago

The 601 had support for some POWER instructions that weren’t part of the PPC ISA and weren’t supported by later chips, I know Apple’s developer notes for these machines mentioned that you had to avoid those.