The RISC-V Proxy Kernel, pk, is a lightweight application execution
environment that can host statically-linked RISC-V ELF binaries. It is
designed to support tethered RISC-V implementations with limited I/O
capability and thus handles I/O-related system calls by proxying them to
a host computer.
This package also contains the Berkeley Boot Loader, bbl, which is a
supervisor execution environment for tethered RISC-V systems. It is
designed to host the RISC-V Linux port.
We assume that the RISCV environment variable is set to the RISC-V tools install path, and that the riscv-gnu-toolchain package is installed. Please note that building the binaries directly inside the source directory is not supported; you need to use a separate build directory.
$ mkdir build
$ cd build
$ ../configure --prefix=$RISCV --host=riscv64-unknown-elf
$ make
$ make install
Alternatively, the GNU/Linux toolchain may be used to build this package,
by setting --host=riscv64-unknown-linux-gnu.
By default, 64-bit (RV64) versions of pk and bbl are built. To
built 32-bit (RV32) versions, supply a --with-arch=rv32i_zicsr_zifencei flag to the
configure command.
To process RVC binaries, supply a --with-arch=rv32ic_zicsr_zifencei flag, because the
emulation code (floating point and miss-aligned load and store) is different in
the RVC case.
The install step installs 64-bit build products into a directory
matching your host (e.g. $RISCV/riscv64-unknown-elf). 32-bit versions
are installed into a directory matching a 32-bit version of your host (e.g.
$RISCV/riscv32-unknown-elf).
Install the riscv-gnu-toolchain, and follow generic build steps.
# pkg_add riscv-elf-binutils riscv-elf-gcc riscv-elf-newlib