Add spike devices

.gitmodules

@@ -142,3 +142,6 @@
 [submodule "tools/install-circt"]
 	path = tools/install-circt
 	url = https://github.com/circt/install-circt/
+[submodule "toolchains/riscv-tools/riscv-spike-devices"]
+	path = toolchains/riscv-tools/riscv-spike-devices
+	url = https://github.com/ucb-bar/spike-devices.git

docs/Software/Spike.rst

@@ -50,3 +50,24 @@ Spike-as-a-Tile can be configured with custom IPC, commit logging, and other beh
 * ``+spike-fast-clint``: Enables fast-forwarding through WFI stalls by generating fake timer interrupts
 * ``+spike-debug``: Enables debug Spike logging
 * ``+spike-verbose``: Enables Spike commit-log generation
+
+Adding a new spike device model
+-------------------------------
+
+Spike comes with a few functional device models such as UART, CLINT, and PLIC.
+However, you may want to add custom device models into Spike such as a block device.
+Example devices are in the ``toolchains/riscv-tools/riscv-spike-devices`` directory.
+These devices are compiled as a shared library that can be dynamically linked to Spike.
+
+To compile these plugins, run ``make`` inside ``toolchains/riscv-tools/riscv-spike-devices``. This will generate a ``libspikedevices.so``.
+
+To hook up a block device to spike and provide a default image to initialize the block device, run
+
+.. code-block:: shell
+
+   spike --extlib=libspikedevices.so --device="iceblk,img=<path to Linux image>" <path to kernel binary>
+
+.
+
+The ``--device`` option consists of the device name and arguments.
+In the above example ``iceblk`` is the device name and ``img=<path to Linux image>`` is the argument passed on to the plugin device.

generators/chipyard/src/main/resources/csrc/spiketile.cc

@@ -447,18 +447,6 @@ chipyard_simif_t::chipyard_simif_t(size_t icache_ways,
   use_stq(false),
   htif(nullptr),
   fast_clint(false),
-  cfg(std::make_pair(0, 0),
-      nullptr,
-      isastr,
-      "MSU",
-      "vlen:128,elen:64",
-      false,
-      endianness_little,
-      pmpregions,
-      std::vector<mem_cfg_t>(),
-      std::vector<size_t>(),
-      false,
-      0),
   accessed_tofrom_host(false),
   icache_ways(icache_ways),
   icache_sets(icache_sets),
@@ -470,6 +458,19 @@ chipyard_simif_t::chipyard_simif_t(size_t icache_ways,
   mmio_inflight(false)
 {
 
+  cfg.initrd_bounds = std::make_pair(0, 0);
+  cfg.bootargs = nullptr;
+  cfg.isa = isastr;
+  cfg.priv = "MSU";
+  cfg.varch = "vlen:128,elen:64";
+  cfg.misaligned = false;
+  cfg.endianness = endianness_little;
+  cfg.pmpregions = pmpregions;
+  cfg.mem_layout = std::vector<mem_cfg_t>();
+  cfg.hartids = std::vector<size_t>();
+  cfg.explicit_hartids = false;
+  cfg.trigger_count = 0;
+
   icache.resize(icache_ways);
   for (auto &w : icache) {
     w.resize(icache_sets);

scripts/build-toolchain-extra.sh

@@ -125,4 +125,10 @@ cd generators/testchipip/uart_tsi
 make
 cp uart_tsi $RISCV/bin
 
+echo '==>  Installing spike-devices'
+cd $RDIR
+git submodule update --init toolchains/riscv-tools/riscv-spike-devices
+cd toolchains/riscv-tools/riscv-spike-devices
+make install
+
 echo "Extra Toolchain Utilities/Tests Build Complete!"