error running litex_vexriscv_linux.resc

[pdp7]

I installed renode_1.8.2_amd64.deb and I am trying to run LiteX on Linux-VexRiscV with renode.

I saw @mateusz-holenko comment in this PR: litex-hub/linux-on-litex-vexriscv#33 (comment)

You can simulate it by starting Renode and typing in monitor:
start @scripts/single-node/litex_vexriscv_linux.resc

I ran this in the monitor:

start @scripts/single-node/litex_vexriscv_linux.resc

but i got an error:

Object reference not set to an instance of an object
  at System.Collections.Generic.LargeArrayBuilder`1[T].GetBuffer (System.Int32 index) [0x00022] in <13c0993ff82548209b09f271bd5e6a78>:0 
  at System.Collections.Generic.LargeArrayBuilder`1[T].CopyTo (System.Collections.Generic.CopyPosition position, T[] array, System.Int32 arrayIndex, System.Int32 count) [0x00041] in <13c0993ff82548209b09f271bd5e6a78>:0 
  at System.Collections.Generic.SparseArrayBuilder`1[T].CopyTo (T[] array, System.Int32 arrayIndex, System.Int32 count) [0x0009a] in <13c0993ff82548209b09f271bd5e6a78>:0 
  at System.Collections.Generic.SparseArrayBuilder`1[T].ToArray () [0x00028] in <13c0993ff82548209b09f271bd5e6a78>:0 
  at System.Linq.Enumerable+Concat2Iterator`1[TSource].ToArray () [0x00024] in <13c0993ff82548209b09f271bd5e6a78>:0 
  at System.Linq.Enumerable.ToArray[TSource] (System.Collections.Generic.IEnumerable`1[T] source) [0x00021] in <13c0993ff82548209b09f271bd5e6a78>:0 
  at Antmicro.Renode.UserInterface.Monitor.RunCommand (AntShell.Commands.ICommandInteraction writer, Antmicro.Renode.UserInterface.Commands.Command command, System.Collections.Generic.IList`1[T] parameters) [0x00406] in <d47614c6567449c69a4ac1c1bdcf6d28>:0 
  at Antmicro.Renode.UserInterface.Monitor.ExecuteCommand (Antmicro.Renode.UserInterface.Tokenizer.Token[] com, AntShell.Commands.ICommandInteraction writer) [0x00133] in <d47614c6567449c69a4ac1c1bdcf6d28>:0 
  at Antmicro.Renode.UserInterface.Monitor.ParseTokens (System.Collections.Generic.IEnumerable`1[T] tokensToParse, AntShell.Commands.ICommandInteraction writer) [0x001d5] in <d47614c6567449c69a4ac1c1bdcf6d28>:0 
  at Antmicro.Renode.UserInterface.Monitor.Parse (System.String cmd, AntShell.Commands.ICommandInteraction writer) [0x001a7] in <d47614c6567449c69a4ac1c1bdcf6d28>:0 
  at Antmicro.Renode.UserInterface.Monitor.ProcessCommand (System.String command, AntShell.Commands.ICommandInteraction writer) [0x00000] in <d47614c6567449c69a4ac1c1bdcf6d28>:0 
  at Antmicro.Renode.UserInterface.Monitor.HandleCommand (System.String cmd, AntShell.Commands.ICommandInteraction ci) [0x00000] in <d47614c6567449c69a4ac1c1bdcf6d28>:0 
  at AntShell.Shell.HandleCommand (System.String cmd, AntShell.Commands.ICommandInteraction ic) [0x000bd] in <892b95394fdf4e18974bb957344bb8b5>:0 
  at AntShell.CommandLine.HandleControlSequence (AntShell.Helpers.ControlSequence seq) [0x00a45] in <892b95394fdf4e18974bb957344bb8b5>:0 
  at AntShell.Terminal.NavigableTerminalEmulator.HandleInput (System.Object input) [0x0002e] in <892b95394fdf4e18974bb957344bb8b5>:0 
  at AntShell.Terminal.NavigableTerminalEmulator.Run (System.Boolean stopOnError) [0x00017] in <892b95394fdf4e18974bb957344bb8b5>:0 
  at AntShell.Shell.Start (System.Boolean stopOnError) [0x000f9] in <892b95394fdf4e18974bb957344bb8b5>:0 
  at Antmicro.Renode.UI.CommandLineInterface+<>c__DisplayClass0_1.<Run>b__3 (System.Object x) [0x00000] in <cbc535240d924f9182150dcd1bce9341>:0 
  at System.Threading.ThreadHelper.ThreadStart_Context (System.Object state) [0x0002c] in <d0e12f672b88444ab4b6d9b2ecf20142>:0 
  at System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) [0x0008d] in <d0e12f672b88444ab4b6d9b2ecf20142>:0 
  at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) [0x00000] in <d0e12f672b88444ab4b6d9b2ecf20142>:0 
  at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state) [0x00031] in <d0e12f672b88444ab4b6d9b2ecf20142>:0 
  at System.Threading.ThreadHelper.ThreadStart (System.Object obj) [0x00012] in <d0e12f672b88444ab4b6d9b2ecf20142>:0 

Any idea how I could troubleshoot?

Thanks!

[pdp7]

It appears that Ubuntu 19.10 has too old of a version of mono.

I installed the latest Stable Mono release is: 6.8.0 Stable (6.8.0.96):
https://www.mono-project.com/download/stable/

with:

Mono JIT compiler version 6.8.0.96 (tarball Wed Jan 15 10:08:18 UTC 2020)

Litex on Linux runs ok with Renode!

cc @mithro

[mithro]

Can renode check the Mono version and return a useful error message in some way?

[mateusz-holenko]

@pdp7 - Good to hear it works!

Ubuntu 19.10 comes by default with mono 5.18, whereas Renode requires at least 5.20. The deb package, however, have correct dependencies so installing it in your system should automatically update mono. I'll take a look into this.

I'll also add a check in the startup script that verifies Renode is run on a correct version of mono as @mithro suggested.

[pgielda]

Btw can't we somehow gracefully detect this error somehow at start and if we detect that mono version is wrong just inform the user about it in a nice(r) way?

[PiotrZierhoffer]

This is already in progress.

An interesting fact - when you install Renode with dpkg on an older mono, it warns you, but does not fail.