diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..3550a30
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use flake
diff --git a/.gitignore b/.gitignore
index 66bf841..a8e6767 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,6 @@ fox32.html
 fox32.wasm
 fox32.js
 fox32.data
+
+**/result
+.direnv/
diff --git a/Makefile b/Makefile
index 8d171be..218a602 100644
--- a/Makefile
+++ b/Makefile
@@ -1,27 +1,9 @@
-TARGET = linux
-ifeq ($(TARGET),linux)
-# default is used for CC
-SDL2_CONFIG = sdl2-config
+SDL2_CONFIG ?= sdl2-config
+FOX32ROM_IN ?= fox32.rom
+
+FOX32ROM_OUT = fox32rom.h
 CFLAGS += -g -Ofast -std=c99 -Wall -Wextra `$(SDL2_CONFIG) --cflags`
 LDFLAGS += `$(SDL2_CONFIG) --libs`
-else
-ifeq ($(TARGET),mingw)
-CC = x86_64-w64-mingw32-gcc
-CFLAGS += -g -Ofast -std=c99 -Wall -Wextra -DWINDOWS
-LDFLAGS += -lmingw32 -lSDL2main -lSDL2
-TARGET_FILE_EXTENSION = .exe
-else
-ifeq ($(TARGET),wasm)
-CC = emcc
-CFLAGS += -O3 -std=c99 -Wall -Wextra
-LDFLAGS += -s TOTAL_MEMORY=70057984 -sALLOW_MEMORY_GROWTH=1 -sUSE_SDL=2 --preload-file fox32os.img
-TARGET_EXTRADEPS = fox32os.img
-TARGET_FILE_EXTENSION = .html
-else
-$(error unknown TARGET)
-endif
-endif
-endif
 
 CFILES = src/main.c \
 		src/bus.c \
@@ -37,20 +19,19 @@ CFILES = src/main.c \
 OBJS = $(addsuffix .o, $(basename $(CFILES)))
 
 .PHONY: all
-all: fox32$(TARGET_FILE_EXTENSION)
-
-FOX32ROM_IN = fox32.rom
-FOX32ROM_OUT = fox32rom.h
+all: fox32
 
 $(FOX32ROM_OUT): $(FOX32ROM_IN)
-	xxd -i $(FOX32ROM_IN) $(FOX32ROM_OUT)
+	cp $(FOX32ROM_IN) fox32.rom
+	xxd -i fox32.rom $(FOX32ROM_OUT)
+	rm -f fox32.rom
 	sed -i -e 's/fox32_rom/fox32rom/' $(FOX32ROM_OUT)
 
-fox32$(TARGET_FILE_EXTENSION): $(TARGET_EXTRADEPS) $(OBJS)
+fox32: $(OBJS)
 	$(CC) -o $@ $(OBJS) $(LDFLAGS)
 
 %.o: %.c $(FOX32ROM_OUT)
 	$(CC) -o $@ -c $< $(CFLAGS)
 
 clean:
-	rm -rf fox32 fox32.exe fox32.wasm fox32.html fox32.data fox32.js fox32rom.h $(OBJS)
+	rm -rf fox32 $(FOX32ROM_OUT) $(OBJS)
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..a10594e
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,528 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_2": {
+      "inputs": {
+        "systems": "systems_2"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_3": {
+      "inputs": {
+        "systems": "systems_3"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_4": {
+      "inputs": {
+        "systems": "systems_4"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_5": {
+      "inputs": {
+        "systems": "systems_5"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_6": {
+      "inputs": {
+        "systems": "systems_6"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_7": {
+      "inputs": {
+        "systems": "systems_7"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_8": {
+      "inputs": {
+        "systems": "systems_8"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "fox32asm": {
+      "inputs": {
+        "flake-utils": "flake-utils_3",
+        "nixpkgs": "nixpkgs"
+      },
+      "locked": {
+        "lastModified": 1707042298,
+        "narHash": "sha256-3sAOFd6y7Qrd/FTO/w+G4VfZeaScAoZFKY4IiVd8cqo=",
+        "ref": "refs/heads/main",
+        "rev": "4d8d3d1c48852f35031de2a37bc32766da2833f4",
+        "revCount": 68,
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox32asm"
+      },
+      "original": {
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox32asm"
+      }
+    },
+    "fox32asm_2": {
+      "inputs": {
+        "flake-utils": "flake-utils_5",
+        "nixpkgs": "nixpkgs_2"
+      },
+      "locked": {
+        "lastModified": 1707042298,
+        "narHash": "sha256-3sAOFd6y7Qrd/FTO/w+G4VfZeaScAoZFKY4IiVd8cqo=",
+        "ref": "refs/heads/main",
+        "rev": "4d8d3d1c48852f35031de2a37bc32766da2833f4",
+        "revCount": 68,
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox32asm"
+      },
+      "original": {
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox32asm"
+      }
+    },
+    "fox32asm_3": {
+      "inputs": {
+        "flake-utils": "flake-utils_8",
+        "nixpkgs": "nixpkgs_6"
+      },
+      "locked": {
+        "lastModified": 1707042298,
+        "narHash": "sha256-3sAOFd6y7Qrd/FTO/w+G4VfZeaScAoZFKY4IiVd8cqo=",
+        "ref": "refs/heads/main",
+        "rev": "4d8d3d1c48852f35031de2a37bc32766da2833f4",
+        "revCount": 68,
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox32asm"
+      },
+      "original": {
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox32asm"
+      }
+    },
+    "fox32os": {
+      "inputs": {
+        "flake-utils": "flake-utils_2",
+        "fox32asm": "fox32asm",
+        "fox32rom": "fox32rom",
+        "foxtools": "foxtools",
+        "nixpkgs": "nixpkgs_5"
+      },
+      "locked": {
+        "lastModified": 1707047316,
+        "narHash": "sha256-bLXyUp8d1mOO5fa9ubjcP7fItfe+9PNPOATJ5nDAhrg=",
+        "ref": "refs/heads/main",
+        "rev": "1a89d1e48e22fa95d85c6575853b4f88f64e26aa",
+        "revCount": 211,
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox32os"
+      },
+      "original": {
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox32os"
+      }
+    },
+    "fox32rom": {
+      "inputs": {
+        "flake-utils": "flake-utils_4",
+        "fox32asm": "fox32asm_2",
+        "nixpkgs": "nixpkgs_3"
+      },
+      "locked": {
+        "lastModified": 1706972604,
+        "narHash": "sha256-r5R3aoFtrctpPoQIE3ynLet9L34WUFlj2PRSKRgQAYg=",
+        "ref": "refs/heads/main",
+        "rev": "f4a7e18b2803ff65eb4182a248028bef6cda7546",
+        "revCount": 181,
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox32rom"
+      },
+      "original": {
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox32rom"
+      }
+    },
+    "fox32rom_2": {
+      "inputs": {
+        "flake-utils": "flake-utils_7",
+        "fox32asm": "fox32asm_3",
+        "nixpkgs": "nixpkgs_7"
+      },
+      "locked": {
+        "lastModified": 1706972604,
+        "narHash": "sha256-r5R3aoFtrctpPoQIE3ynLet9L34WUFlj2PRSKRgQAYg=",
+        "ref": "refs/heads/main",
+        "rev": "f4a7e18b2803ff65eb4182a248028bef6cda7546",
+        "revCount": 181,
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox32rom"
+      },
+      "original": {
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox32rom"
+      }
+    },
+    "foxtools": {
+      "inputs": {
+        "flake-utils": "flake-utils_6",
+        "nixpkgs": "nixpkgs_4"
+      },
+      "locked": {
+        "lastModified": 1707042981,
+        "narHash": "sha256-RJwtT0BUBM0XlpzUymrwvI5JAsP1drjggIjDJcnWq8o=",
+        "ref": "refs/heads/main",
+        "rev": "f690eb07c46d59c9430bc004f72f6fba271e2415",
+        "revCount": 43,
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox-tools"
+      },
+      "original": {
+        "type": "git",
+        "url": "https://githug.xyz/xenia/fox-tools"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1697009197,
+        "narHash": "sha256-viVRhBTFT8fPJTb1N3brQIpFZnttmwo3JVKNuWRVc3s=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "01441e14af5e29c9d27ace398e6dd0b293e25a54",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1697009197,
+        "narHash": "sha256-viVRhBTFT8fPJTb1N3brQIpFZnttmwo3JVKNuWRVc3s=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "01441e14af5e29c9d27ace398e6dd0b293e25a54",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs_3": {
+      "locked": {
+        "lastModified": 1697009197,
+        "narHash": "sha256-viVRhBTFT8fPJTb1N3brQIpFZnttmwo3JVKNuWRVc3s=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "01441e14af5e29c9d27ace398e6dd0b293e25a54",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs_4": {
+      "locked": {
+        "lastModified": 1697009197,
+        "narHash": "sha256-viVRhBTFT8fPJTb1N3brQIpFZnttmwo3JVKNuWRVc3s=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "01441e14af5e29c9d27ace398e6dd0b293e25a54",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs_5": {
+      "locked": {
+        "lastModified": 1697009197,
+        "narHash": "sha256-viVRhBTFT8fPJTb1N3brQIpFZnttmwo3JVKNuWRVc3s=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "01441e14af5e29c9d27ace398e6dd0b293e25a54",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs_6": {
+      "locked": {
+        "lastModified": 1697009197,
+        "narHash": "sha256-viVRhBTFT8fPJTb1N3brQIpFZnttmwo3JVKNuWRVc3s=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "01441e14af5e29c9d27ace398e6dd0b293e25a54",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs_7": {
+      "locked": {
+        "lastModified": 1697009197,
+        "narHash": "sha256-viVRhBTFT8fPJTb1N3brQIpFZnttmwo3JVKNuWRVc3s=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "01441e14af5e29c9d27ace398e6dd0b293e25a54",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs_8": {
+      "locked": {
+        "lastModified": 1697009197,
+        "narHash": "sha256-viVRhBTFT8fPJTb1N3brQIpFZnttmwo3JVKNuWRVc3s=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "01441e14af5e29c9d27ace398e6dd0b293e25a54",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "fox32os": "fox32os",
+        "fox32rom": "fox32rom_2",
+        "nixpkgs": "nixpkgs_8"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_2": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_3": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_4": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_5": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_6": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_7": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_8": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..6e170fb
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,44 @@
+{
+  description = "fox32 emulator";
+
+  inputs = {
+    fox32rom.url = "git+https://githug.xyz/xenia/fox32rom";
+    fox32os.url = "git+https://githug.xyz/xenia/fox32os";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, fox32rom, fox32os, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (sys:
+      let pkgs = import nixpkgs { system = sys; };
+          rom = fox32rom.packages.${sys}.fox32rom;
+          deps = [ pkgs.SDL2.dev pkgs.xxd ];
+          os = fox32os.packages.${sys}.fox32os;
+
+          fox32 = pkgs.stdenv.mkDerivation {
+            name = "fox32";
+            src = ./.;
+            buildInputs = deps;
+
+            FOX32ROM_IN = "${rom}/bin/fox32.rom";
+            installPhase = ''
+              mkdir -p $out/bin
+              cp fox32 $out/bin/fox32
+            '';
+          };
+
+          fox32-with-os = pkgs.writeScriptBin "fox32-with-os" ''cp ${os}/bin/fox32os.img /tmp/fox32os.img && chmod u+w /tmp/fox32os.img && ${fox32}/bin/fox32 --disk /tmp/fox32os.img'';
+
+      in rec {
+        packages.fox32 = fox32;
+        packages.fox32-with-os = fox32-with-os;
+        packages.default = fox32;
+
+        devShells.default = pkgs.mkShell {
+          packages = deps;
+          shellHook = ''
+            export FOX32ROM_IN="${rom}/bin/fox32.rom"
+          '';
+        };
+      }
+    );
+}