Panther - 2 Kernels?

Posted:
in macOS edited January 2014
If Panther is to add 64bit support for the 970, how will this work with G3s/G4s? Will Apple have to support 2 kernels (32bit and 64bit versions), or will they build a single 32bit kernel with optional 64bit extensions to support the new hardware?



Any thoughts?

Comments

  • Reply 1 of 8
    cubedudecubedude Posts: 1,556member
    I thought 64bit processors were backwards compatible with 32bit processors, so it shouldn't be any problem for Panther to support both 32 and 64bit processors.
  • Reply 2 of 8
    billybobskybillybobsky Posts: 1,914member
    Quote:

    Originally posted by CubeDude

    I thought 64bit processors were backwards compatible with 32bit processors, so it shouldn't be any problem for Panther to support both 32 and 64bit processors.



    at some point soon though the shit will hit the fan, and all 32 bit processors will not be supported...
  • Reply 3 of 8
    Well, We have already made that switch once with the 68k machines.



    On a side note no panther will not have two kernels
  • Reply 4 of 8
    cubedudecubedude Posts: 1,556member
    Quote:

    Originally posted by billybobsky

    at some point soon though the shit will hit the fan, and all 32 bit processors will not be supported...



    But that won't happen immediately, so Panther will not have 2 kernals. Later versions of OSX might.
  • Reply 5 of 8
    nguyenhm16nguyenhm16 Posts: 195member
    Quote:

    Originally posted by Mudd

    If Panther is to add 64bit support for the 970, how will this work with G3s/G4s? Will Apple have to support 2 kernels (32bit and 64bit versions), or will they build a single 32bit kernel with optional 64bit extensions to support the new hardware?



    Any thoughts?




    Probably the same way Solaris, HP-UX, IRIX, AIX do it, two kernels. {Free/Net}BSD also have 32 and 64 kernels compiled from the same source. The difference between 32 and 64 modes at the kernel level (size of integral types, pointers, etc.) are too great for there be mere 'extensions'. The 64 bit kernel will obviously support the same 32 bit ABI (application binary interface) as the 32 bit kernel, in addition to a new 64 bit ABI. Again, jsut like allt he other big UNIXes out there.



    Apple would probably port parts of the OS to 64 bit code on an as needed basis, since existing 32 bit code would still work. This is actually much easier than the 68k->PPC transition, since there is no binary translation needed.



    EDIT: In order for Panther to fully support 64 bit CPUs (e.g. > 4GB addressing, etc.) and not to merely RUN on a 64 bit CPU, it will need to have a specific 64 bit kernel. Obviously such a kernel would not run on 32bit hardware, so I think there will be two kernels (even if Apple bundles both of them together to look like one file). Just like in the PC world, you can run existing 32bit software and OSes unmodified on AMD64 hardware, but in order to take advantage of AMD64's 64bit mode, you need a kernel built especially for that mode.
  • Reply 6 of 8
    I don't claim to know much technical stuff about computer hardware, but I'm guessing since most of Apple's hardware is rather limited in upgradability (and, as I hear, it takes a printing press to get a 970 on any motherboard) I don't think they're about to off all pre64-bit processors just yet. Maybe in a few years but not soon, anyway. Eh, correct me if I'm wrong in thinking that?
  • Reply 7 of 8
    amorphamorph Posts: 7,112member
    Quote:

    Originally posted by Dog Almighty

    I don't claim to know much technical stuff about computer hardware, but I'm guessing since most of Apple's hardware is rather limited in upgradability (and, as I hear, it takes a printing press to get a 970 on any motherboard) I don't think they're about to off all pre64-bit processors just yet. Maybe in a few years but not soon, anyway. Eh, correct me if I'm wrong in thinking that?



    It's the POWER 4 MCM (that's a multi chip module with 4 POWER 4 CPUs on board - or it's 1,900) that requires 700 pounds of pressure to mount. The 970 shouldn't require more than any other CPU does.
  • Reply 8 of 8
    Quote:

    Originally posted by Amorph

    It's the POWER 4 MCM (that's a multi chip module with 4 POWER 4 CPUs on board - or it's 1,900) that requires 700 pounds of pressure to mount. The 970 shouldn't require more than any other CPU does.



    Ah. Now it's all clear.
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