From 6b2063c6abd1b42fe51a711c32c891ead15f502a Mon Sep 17 00:00:00 2001
From: Toby Jaffey <toby@ringtailsoftware.co.uk>
Date: Thu, 11 Dec 2025 11:53:23 +0000
Subject: [PATCH] Build arduino code (for AVR) and allow test in qemu

---
 Dockerfile            | 14 ++++++++++++--
 README.md             |  4 ++--
 host-arduino/Makefile | 12 +++++++++---
 host-arduino/config.h |  2 +-
 4 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 78f15cd..7b0d8d2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,6 +3,11 @@ ENV LANG C.UTF-8
 ENV LC_ALL C.UTF-8
 RUN apt-get -y update
 
+# tzdata
+ARG DEBIAN_FRONTEND=noninteractive
+ENV TZ=Etc/UTC
+RUN apt-get install -y tzdata
+
 # for unity test
 RUN apt-get install -y ruby xxd
 
@@ -13,8 +18,8 @@ RUN apt-get install -y gcc-riscv64-unknown-elf build-essential
 RUN apt-get install -y curl
 RUN curl https://raw.githubusercontent.com/tristanisham/zvm/master/install.sh | bash
 ENV ZVM_INSTALL /root/.zvm/self
-ENV PATH="$PATH:/root/.zvm/bin:/root/.zvm/self"
-ENV export PATH="$/.zvm/bin"
+ENV PATH "$PATH:/root/.zvm/bin:/root/.zvm/self"
+ENV PATH "$PATH:/root/.zvm/bin"
 RUN zvm i 0.15.2
 
 # rust
@@ -22,3 +27,8 @@ RUN apt-get install -y rustup libclang1
 RUN rustup default stable
 RUN rustup target add riscv32im-unknown-none-elf
 RUN apt-get install -y libclang1
+
+# arduino
+RUN curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | sh
+RUN arduino-cli core install arduino:avr
+RUN apt-get install -y qemu-system-misc
diff --git a/README.md b/README.md
index 1d9b777..a01812a 100644
--- a/README.md
+++ b/README.md
@@ -86,7 +86,7 @@ int main(int argc, char *argv[]) {
  * [host](host) vm host which loads a binary and runs to completion, handling multiple syscall types
  * [host-mini](host-mini) minimal vm host (shown above), with baked in bytecode
  * [host-parallel](host-parallel) parallel vm host running multiple vm instances concurrently, with baked in bytecode
- * [host-arduino](host-arduino) vm host as Arduino sketch (tested on Arduino Uno ATmega328P, uses 9950 bytes of flash/1254 bytes RAM)
+ * [host-arduino](host-arduino) vm host as Arduino sketch (`make test` to run AVR code in qemu)
  * [apps/helloworld](apps/helloworld) C hello world program
  * [apps/conio](apps/conio) C console IO demo
  * [apps/lissajous](apps/lissajous) C console lissajous curve (showing softfp, floating point)
@@ -112,7 +112,7 @@ Then, from inside the docker shell
 
 ## Native build
 
-The example VM hosts should all build with any C compiler. To build all of the examples in `apps`, you will need a RISC-V cross compiler, Zig 0.15.2 and Rust (stable).
+The example VM hosts should all build with any C compiler. To build all of the examples in `apps`, you will need a RISC-V cross compiler, Zig 0.15.2 and Rust (stable). To build the example `host-arduino` you will need `arduino-cli`.
 
 ## Quickstart API
 
diff --git a/host-arduino/Makefile b/host-arduino/Makefile
index ab12a93..58804ad 100644
--- a/host-arduino/Makefile
+++ b/host-arduino/Makefile
@@ -1,8 +1,10 @@
-# The purpose of this Makefile is to auto-generate the Arduino example
+# Auto-generate the Arduino example
 # Arduino cannot set -DUVM32_MEMORY_SIZE, so add a config file
 # Arduino expects .cpp files
 
-make:
+# make test, runs in qemu
+
+all:
 	echo '#include "config.h"' > uvm32.cpp
 	cat ../uvm32/uvm32.c >> uvm32.cpp
 	cp ../uvm32/uvm32.h uvm32.h
@@ -10,6 +12,10 @@ make:
 	cp ../common/uvm32_common_custom.h uvm32_common_custom.h
 	cp ../common/uvm32_sys.h uvm32_sys.h
 	xxd -i ../precompiled/mandel.bin | sed -e "s/unsigned char/const unsigned char/" > mandel.h
+	arduino-cli compile -b arduino:avr:uno -e
+
+test: all
+	qemu-system-avr -machine uno -bios build/arduino.avr.uno/host-arduino.ino.elf -nographic -serial mon:stdio
 
 clean:
-	rm -f uvm32.cpp uvm32.h mini-rv32ima.h uvm32_common_custom.h uvm32_sys.h mandel.h
+	rm -rf uvm32.cpp uvm32.h mini-rv32ima.h uvm32_common_custom.h uvm32_sys.h mandel.h build
diff --git a/host-arduino/config.h b/host-arduino/config.h
index 5952a70..53db8d9 100644
--- a/host-arduino/config.h
+++ b/host-arduino/config.h
@@ -1,2 +1,2 @@
 // Arduino cannot do -DUVM32_MEMORY_SIZE, so set this explicitly
-#define UVM32_MEMORY_SIZE 1024
+#define UVM32_MEMORY_SIZE 512