1 A plan for Fedora/RISC-V
2 ----------------------------------------------------------------------
3 by Richard W.M. Jones (rjones@redhat.com)
5 Project home page: https://fedoraproject.org/wiki/Architectures/RISC-V
11 Stuck getting QEMU to work. See:
12 https://groups.google.com/a/groups.riscv.org/forum/#!topic/sw-dev/fdbhLufxezA
14 Will likely wait until September when we may see a working QEMU that
15 is compatible with the latest RISC-V software.
18 The aim of the project
19 ----------------------
21 Get Fedora running on the RISC-V architecture! This will just be an
22 initial pass, which we're calling an "experimental architecture". It
23 won't even be a secondary architecture for perhaps 1 to 3 years.
25 About Fedora: https://getfedora.org/
26 About RISC-V: https://riscv.org/
27 https://en.wikipedia.org/wiki/RISC-V
28 lowRISC: http://www.lowrisc.org/
31 How do we expect people to consume Fedora/RISC-V?
32 -------------------------------------------------
34 Most users will download binaries. Of course source will be available
35 for [almost*] everything, buildable from source RPMS.
37 Currently no hardware is available, so you either have to run RISC-V
38 on an FPGA, or use QEMU emulation.
40 For the FPGA option, you will need a Nexys 4 DDR development kit
41 costing around US$341, plus an ordinary micro SD card (8+ GB), plus a
42 host Fedora/x86-64 computer.
44 - Maximum system RAM is 128 MB (1 GB is available if you use the
45 other far more expensive FPGA development kit)
47 - There is a 115200 bps 8n1 serial port.
49 - There is no ethernet and no display.
51 For the QEMU emulation option, see below.
53 - QEMU has unlimited system RAM.
55 - Network access is available.
58 [*] Some CPU peripherals use proprietary IP. The aim is to replace
59 these with open equivalents eventually. Building the FPGA bitstream
60 will require proprietary tools, although the source itself is free
64 What parts of Fedora are we aiming to build?
65 --------------------------------------------
67 The @Core packages (as RPMs), rpmbuild, gcc, and a bootable binary
70 Only 64 bit RISC-V will be targeted.
72 Once those are done, we can declare victory.
75 What parts of Fedora are we *not* aiming to build?
76 --------------------------------------------------
78 Nothing outside @Core except for specific compilers and build tools.
82 Not Koji (at least, not at first).
84 Not Grub nor EDK2. We will initially use the Berkeley bootloader
85 (bbl), but aim for a standard bootloader later.
88 Where will we build it?
89 -----------------------
91 The packages which are run on the host (x86-64) computer will be built
92 in COPR (https://copr.fedorainfracloud.org/).
94 However the majority of packages will be built on RISC-V itself.
95 Since there are no RISC-V builders, and we cannot really provide them,
96 initially developers will be building them on their own FPGAs / QEMUs
99 Getting build infrastructure would be a more long-term aim.
104 [See also: https://fedoraproject.org/wiki/Architectures/AArch64/Bootstrap]
108 (1a) riscv-qemu.x86_64: QEMU + RISC-V system emulation
110 Not upstream, fork of qemu 2.5.0.
111 https://github.com/riscv/riscv-qemu
112 Status: done http://copr-fe.cloud.fedoraproject.org/coprs/rjones/riscv
114 Note this package runs on x86-64 hosts, and is intended for people who
115 want to run Fedora/RISC-V but who do not have FPGA/hardware.
119 Various sources, see:
120 http://www.lowrisc.org/docs/untether-v0.2/fpga-demo/
124 (2a) GNU cross-compiler toolchain.
126 https://github.com/lowRISC/riscv-gnu-toolchain
127 Status: done http://copr-fe.cloud.fedoraproject.org/coprs/rjones/riscv
129 (2b) Berkley Bootloader (bbl)
131 https://github.com/lowrisc/riscv-pk.git
132 Status: done http://copr-fe.cloud.fedoraproject.org/coprs/rjones/riscv
134 Used to boot the kernel and mount the root filesystem on FPGAs and
139 (3a) kernel.riscv64: The Linux kernel, cross-compiled.
141 Current status: Not upstream, fork of Linux 4.6.
142 https://github.com/lowrisc/riscv-linux
144 (3b) "Just enough userspace"
146 The following packages, cross-compiled from x86-64 host to riscv64
147 target filesystem. The aim is to have a filesystem (not RPMs) that
148 can be booted on RISC-V hardware or under QEMU, which will be
149 sufficient to use to compile RPMs.
158 filesystem.riscv64 (?)
166 We will also need to add the following noarch packages (these do not
167 need to be compiled, they can just be copied from another Fedora
171 ca-certificates.noarch
172 crypto-policies.noarch
173 emacs-filesystem.noarch
174 fedora-release.noarch
179 ==== At this point, Fedora on RISC-V will be self-hosting ====
183 (4a) kernel.riscv64: The Linux kernel, compiled as an RPM on RISC-V.
187 (See the above list of packages, but built from SRPMs)
189 (4c) Recreate the filesystem from RPMs.
191 Distribute an initial bootable binary disk image which is completely
192 built from RPMs (but note, not created by Anaconda).
194 (4d) Continue compiling all other RPMs from @Core.
196 As more packages are compiled, distribute them as RPMs and distribute
197 updated bootable binary disk image.
199 (4e) Declare victory and celebrate!
205 What architecture string to use (eg. in RPM package names)? There are
206 32, 64 and (in theory) 128 bit variants of RISC-V. GNU uses "riscv64".