4 ms·
It's easier to switch from one fab to another than from x86 to another cpu architecture.
by legulere 6y ago
It's easier to switch from one fab to another than from x86 to another cpu architecture.
- Koshkin 6y agoLinux has done it.
- ragebol 6y agoLinux is not tied to a single architecture. Not sure if it ever has been, really.
- pedrocr 6y agoFrom the original announcement email by Linus: > It is NOT protable (uses 386 task switching etc), and it probably never will support anything other than AT-harddisks, as that's all I have :-(. And he meant it too, as later in the thread when someone says they don't believe him about the non-portability: > Simply, I'd say that porting is impossible. It's mostly in C, but most people wouldn't call what I write C. It uses every conceivable feature of the 386 I could find, as it was also a project to teach me about the 386. As already mentioned, it uses a MMU, for both paging (not to disk yet) and segmentation. It's the segmentation that makes it REALLY 386 dependent (every task has a 64Mb segment for code & data - max 64 tasks in 4Gb. Anybody who needs more than 64Mb/task - tough cookies). This is a historical curiosity of course. The Linux kernel supports more architectures than anything else.
- close04 6y ago> This is a historical curiosity of course. Mostly because of the slow adoption which allowed a lot of flexibility. It's much easier to move around when you don't have the baggage of millions of users and applications to consider. Even Windows ran on plenty of non-x86 architectures usually because they got in on the ground floor before there was baggage to migrate. And even now you can run it on ARM but without much traction because people hate losing functionality.
- Macha 6y agoWas there a effort to make it cross platform, or just the tech that looked 386 only at the time like a MMU becoming more widespread (I remember a fail0verflow talk on ps4 linux a while back where they mentioned a MMU and clock as requirements to port Linux to an architecture)?
- monocasa 6y agoMMU is less of a requirement these days, since the uclinux patches were upstreamed. And it was ported to Alpha early on to be ported to a very 'not 386' style architecture. Before that it was very x86 specific.
- Koshkin 6y agoAmazingly enough, it only took 4 years from its birth for Linux to get ported to DEC Alpha and Sun SPARC. Talk about going viral!
- close04 6y agoLinux has supported a lot of CPU architectures pretty much from childhood but never had any legacy to carry over. Legacy is the real killer when talking about such migrations and the bigger the footprint with consumers, the bigger the legacy. Linux never had a significant footprint in any long existing segment at the time they migrated from one architecture to another, especially not in a consumer one. Take Apple and their move from 68K to PPC to x86 to ARM.
- throwaway8941 6y agoYet another reason to use FOSS as much as physically possible.
- deleted 6y ago[deleted]
- deleted 6y ago[deleted]
- Koshkin 6y agoAt the hardware level, I wonder why, though - don't the modern x86 CPUs have a completely different internal architecture anyway?
- amelius 6y agoBecause to change to another fab you "just" have to get a single transistor (or a few devices) working (and duplicate that a billion times). Changing to another ISA requires a lot of redesign.