====== Spike ======

Spike is the canonical RISC-V ISA simulator. It supports several ISA extensions, including some that are not yet ratified. See the [[https://github.com/riscv/riscv-isa-sim|README]] on %%GitHub%% for more information.

It is available from ports as [[http://www.freshports.org/emulators/riscv-isa-sim|emulators/riscv-isa-sim]].

==== Building From Source ====

<code>
setenv PREFIX $HOME/riscv

git clone https://github.com/freebsd-riscv/riscv-isa-sim
cd riscv-isa-sim
mkdir build && cd build
setenv CPPFLAGS -DRISCV_ENABLE_DIRTY=1
../configure --prefix=$PREFIX
gmake install
</code>

==== Build a small rootfs for Spike to be used as mdroot (memory disk) ====

Spike has no network or disk controller, so the only way to get a root filesystem is to embed one in the kernel.

Build a memory disk with a basic set of files:

<code>
fetch https://raw.githubusercontent.com/bukinr/riscv-tools/master/image/basic.files
tools/tools/makeroot/makeroot.sh -s 32m -f basic.files mdroot.img $DESTDIR
</code>

Add the following to your kernel config to include the memory disk:

<code>
options         MD_ROOT
options         MD_ROOT_SIZE=32768      # 32MB ram disk
makeoptions     MFS_IMAGE=/path/to/mdroot.img
options         ROOTDEVNAME=\"ufs:/dev/md0\"
</code>

==== Run Spike ====

<code>
spike -m2048 -p2 /path/to/bbl
</code>