boots in qemu

4 files changed, 61 insertions, 1 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..fcfc4a1
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+result*
diff --git a/boot.asm b/boot.asm
new file mode 100644
index 0000000..ddef7eb
--- /dev/null
+++ b/boot.asm
@@ -0,0 +1,7 @@
+; yoinked from osdev.org
+hang:
+    jmp hang
+
+times 510-($-$$) db 0 ; 2 bytes less now
+db 0x55
+db 0xAA
diff --git a/flake.nix b/flake.nix
index 49d4e35..6f3484c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -6,6 +6,13 @@
     nixpkgs,
     self,
     ...
-  }: {
+  }: let
+    system = "x86_64-linux";
+    pkgs = nixpkgs.legacyPackages.${system};
+  in {
+    packages.${system}.default = pkgs.callPackage ./package.nix {};
+    devShells.${system}.default = pkgs.mkShell {
+      inputsFrom = [self.packages.${system}.default];
+    };
   };
 }
diff --git a/package.nix b/package.nix
new file mode 100644
index 0000000..150b46b
--- /dev/null
+++ b/package.nix
@@ -0,0 +1,45 @@
+{
+  stdenv,
+  nasm,
+  qemu,
+  ...
+}: let
+  bootImg = "boot";
+in
+  stdenv.mkDerivation {
+    pname = "bootler";
+    version = "0.1.0";
+    src = ./.;
+    buildPhase = ''
+      ${nasm}/bin/nasm boot.asm -o ${bootImg}
+    '';
+    installPhase = ''
+      mkdir -p $out/bin
+      cp ${bootImg} $out/bin
+
+      # create emulation binary
+      cat<<EOF>$out/bin/bootler
+      #!/usr/bin/env bash
+
+      # create temp dir
+      mkdir -p ./.bootler
+      cp $(echo $out)/bin/${bootImg} ./.bootler/${bootImg}
+      chmod a+w ./.bootler/${bootImg}
+
+      echo "press any key to continue. Qemu will clear the screen..."
+      read -s -n 1
+
+      # run image
+      ${qemu}/bin/qemu-system-x86_64 \
+        -nographic \
+        -hda ./.bootler/${bootImg}
+
+      # clean up
+      rm ./.bootler -r
+
+      EOF
+
+      chmod +x $out/bin/${bootImg}
+      chmod +x $out/bin/bootler
+    '';
+  }