3 - What precisely is offered by RISC-V?
5 - Bootstrapping Fedora.
7 - The state of RISC-V software development and the community.
9 - Are open source ISAs in Red Hat's future?
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15 fixed size 32 bit instructions
16 compressed instructions extension
17 32 general purpose registers
18 32 floating point registers (extension)
22 proven to be patent-free
26 Micro-architecture independent as far as possible
28 No register windows, branch delay slots etc
29 Royalty free, no licensing
34 Priv spec 1.7 -> 1.9/2.0
36 4 open source core designs, Rocket, BOOM and two others
37 Chisel generates Verilog
38 Includes cache hierarchy
39 Includes coherence between L2 caches
41 Targets C++ (simulation), FPGA or ASIC
42 Proprietary tools needed if you go FPGA or ASIC route
49 LowRISC = "RPi for grown-ups"
51 Many FPGA implementations
52 Lots of research groups
53 Lots of small dev groups
55 Some large companies looking: NVidia, Google, AMD, HPE, IBM, Mellanox,
56 Microsemi, Microsoft, WD, ...
60 any other sort of hardware, serial, ethernet, display, SATA, DDR, ...
61 PCI (SiFive have done some work)
62 much of this is filled in with proprietary "IP"
68 What else goes into a server?
70 standard boot environment (like SBBR on ARM)
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79 Current software is crap
82 Basically an embedded system
88 Four stage bootstrap process
89 Stage 3 is a "hack job" containing a mix of cross-compiled
90 packages built on the host, layered with "--nodeps"-installed RPMs on top.
92 Stage 4 is the clean image built entirely from RPMs, with all
93 dependencies satisfied and all files controlled by RPM.
95 The bootstrap process has generally speaking been quite easy (just
96 tedious and slow because it all happens under emulation).
98 All the complicated bits (ie. kernel, toolchain) were done already
99 upstream and there haven't been any packages that were difficult to
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104 RISC-V software development and the community
106 Lots of momentum. Considerably more realistic than previous
109 Friendly and helpful upstream community.
111 Far too many of non-upstream forks around.
113 Some concerns about changes/instability in the architecture, but
114 at least for userspace things seem pretty solid.
116 Really needs virtio support. Someone from the Fedora community
117 is looking into this.
119 Fedora community have been very active with packaging.
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123 What does this mean for Red Hat?
137 Summary and questions