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yes - ARM ISA is copyrighted. To implement it, you need an ISA license. ARM typically makes this license cost almost the same as the license for an already impl
by writepub 8y ago
yes - ARM ISA is copyrighted. To implement it, you need an ISA license. ARM typically makes this license cost almost the same as the license for an already implemented core, which is why most vendors drag-and-drop ARM cores into their designs
- FPGAhacker 8y agoBut does this cover software emulation?
- wmf 8y agoQEMU exists so I guess they're OK with software emulation but Arm seems to go on the attack at the slightest whiff of an unlicensed hardware implementation.
- mcbits 8y agoAre they really OK with it or are they just legally powerless to stop it? That is the question.
- bluejekyll 8y agoIt may not be in their interest to stop it, as those are generally used for testing and building software to target ARM, which helps with their potential market share. Similarly, MS offers free VMs to developers for Windows so that you can build and test against Windows without cost.
- est31 8y agoDo you have a link to those VMs?
- ninjaoxygen 8y agohttps://developer.microsoft.com/en-us/windows/downloads/virtual-machines https://developer.microsoft.com/en-us/windows/downloads/virt...
- est31 8y agoThat's very cool. Thank you!
- ohazi 8y agoQemu is used to by software developers to build better software/infrastructure/tooling for the chips that arm gets royalties from. It would be stupid for them to put up a roadblock here.
- monocasa 8y agoThat's grey area. Intel has publicly asserted that their patents apply to emulation, but is hasn't hit the courts AFAIK. https://arstechnica.com/information-technology/2017/06/intel-fires-warning-shots-at-microsoft-claims-x86-emulation-is-a-patent-minefield/ https://arstechnica.com/information-technology/2017/06/intel...
- kevin_thibedeau 8y agoTheir implementation is copyrighted. What prevents royalty-free clones is patents. MIPS was similar with certain key patents preventing clones until their recent pivot. You can clone legacy ARM architectures that aren't patent encumbered.
- tachyonbeam 8y agoI think most posters in this thread are forgetting this point. RISV-V will have a key advantage because not only will it be free, but you’ll have access to high quality free implementations you can redistribute and remix without copyright issues.
- pjc50 8y agoPeople seem to forget that manufacturing and distribution of hardware is the expensive bit. "You" is never going to be an ordinary member of the public.
- sitkack 8y agoMaking ones own small batch riscv run is in the the price range of a good used Nissan Leaf to a new 3 Series. That is for delivered silicon. Fpga implementations start at $5. Individuals “waste” both of those amounts of money all the time.