From 5adfb0230f7a3b42b29c53af52b54080d8514ddf Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Tue, 5 Dec 2023 23:16:53 +0000
Subject: [PATCH] WIP generate bootable disk image with partition table

---
 modules/ext4fs.nix                     |  2 +-
 modules/outputs/diskimage.nix          | 52 ++++++++++++++++++++++++++
 modules/outputs/extlinux.nix           | 13 ++++---
 overlay.nix                            |  2 +
 pkgs/run-liminix-vm/run-liminix-vm.fnl | 16 +++++---
 5 files changed, 73 insertions(+), 12 deletions(-)
 create mode 100644 modules/outputs/diskimage.nix

diff --git a/modules/ext4fs.nix b/modules/ext4fs.nix
index e31dcceb..db3fd0f4 100644
--- a/modules/ext4fs.nix
+++ b/modules/ext4fs.nix
@@ -30,7 +30,7 @@ in
         } ''
           cp -a ${o.rootfsFiles} tmp
           ${if config.boot.loader.extlinux.enable
-            then "(cd tmp && ln -s ${o.extlinux} boot)"
+            then "(cd tmp && chmod -R +w . && rmdir boot && cp -a ${o.extlinux} boot)"
             else ""
           }
           size=$(du -s --apparent-size --block-size 1024 tmp |cut -f1)
diff --git a/modules/outputs/diskimage.nix b/modules/outputs/diskimage.nix
new file mode 100644
index 00000000..a29db929
--- /dev/null
+++ b/modules/outputs/diskimage.nix
@@ -0,0 +1,52 @@
+{
+  config
+, pkgs
+, lib
+, ...
+}:
+let
+  inherit (lib) mkOption types concatStringsSep;
+  o = config.system.outputs;
+  phram_address = lib.toHexString (config.hardware.ram.startAddress + 256 * 1024 * 1024);
+in {
+#  imports = [ ./flashimage.nix ];
+  options.system.outputs = {
+    diskimage = mkOption {
+      type = types.package;
+      description = ''
+        diskimage
+        *********
+
+        This creates a disk image file with a partition table containing
+        the contents of ``outputs.rootfs`` as its only partition.
+      '';
+    };
+    vmdisk = mkOption {  type = types.package; };
+  };
+
+  config = {
+    system.outputs = {
+      diskimage =
+        let
+          o = config.system.outputs;
+        in pkgs.runCommand "diskimage" {
+          depsBuildBuild = [ pkgs.pkgsBuildBuild.util-linux ];
+        } ''
+          # leave 4 sectors at start for partition table
+          # and alignment to 2048 bytes (does that help?)
+          dd if=${o.rootfs} of=$out bs=512 seek=4 conv=sync
+          echo '4,-,L,*' | sfdisk $out
+        '';
+      vmdisk = pkgs.runCommand "vmdisk" {} ''
+        mkdir $out
+        cd $out
+        ln -s ${o.diskimage} ./diskimage
+        cat > run.sh <<EOF
+        #!${pkgs.runtimeShell}
+        ${pkgs.pkgsBuildBuild.run-liminix-vm}/bin/run-liminix-vm  --arch ${pkgs.stdenv.hostPlatform.qemuArch} --u-boot ${pkgs.ubootQemuArm}/u-boot.bin --phram-address 0x${phram_address} --disk-image ${o.diskimage} /dev/null /dev/null
+        EOF
+        chmod +x run.sh
+      '';
+    };
+  };
+}
diff --git a/modules/outputs/extlinux.nix b/modules/outputs/extlinux.nix
index c8db8be3..a4d3516d 100644
--- a/modules/outputs/extlinux.nix
+++ b/modules/outputs/extlinux.nix
@@ -20,17 +20,18 @@ in {
     system.outputs.extlinux = pkgs.runCommand "extlinux" {} ''
       mkdir $out
       cd $out
-      ln -s ${o.dtb} dtb
-      ln -s ${o.initramfs} initramfs
+      # cp {o.dtb} dtb
+      cp ${o.initramfs} initramfs
       gzip -9f < ${o.kernel} > kernel.gz
-      cat > extlinux.conf << _EOF
+      mkdir extlinux
+      cat > extlinux/extlinux.conf << _EOF
       menu title Liminix
       timeout 100
       label Liminix
-        kernel kernel.gz
-        initrd initramfs
-        fdt dtb
+        kernel /boot/kernel.gz
+        initrd /boot/initramfs
         append ${cmdline}
+        # fdt /boot/dtb
       _EOF
     '';
   };
diff --git a/overlay.nix b/overlay.nix
index 8a890712..4bea4acd 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -210,6 +210,8 @@ extraPkgs // {
     extraConfig = ''
       CONFIG_CMD_UBI=y
       CONFIG_CMD_UBIFS=y
+      CONFIG_BOOTSTD=y
+      CONFIG_BOOTMETH_DISTRO=y
     '';
   };
 }
diff --git a/pkgs/run-liminix-vm/run-liminix-vm.fnl b/pkgs/run-liminix-vm/run-liminix-vm.fnl
index 50be2301..9d059cf4 100644
--- a/pkgs/run-liminix-vm/run-liminix-vm.fnl
+++ b/pkgs/run-liminix-vm/run-liminix-vm.fnl
@@ -36,7 +36,9 @@
   (match args
     ["--background" dir & rest] (assoc (parse-args rest) :background dir)
     ["--u-boot" bin & rest]
-    (assoc (parse-args rest) :u-boot (pad-file bin (* 4 1024) "\xff"))
+    (assoc (parse-args rest) :u-boot (pad-file bin (* 64 1024) "\xff"))
+    ["--disk-image" image & rest ] (assoc (parse-args rest)
+                                          :disk-image (pad-file image 1024))
     ["--arch" arch & rest] (assoc (parse-args rest) :arch arch)
     ["--phram-address" addr & rest] (assoc (parse-args rest) :phram-address addr)
     ["--lan" spec & rest] (assoc (parse-args rest) :lan spec)
@@ -73,9 +75,12 @@
    ])
 
 
-(fn bootable [cmdline uboot]
+(fn bootable [cmdline uboot disk]
   (if uboot
-      ["-drive" (.. "if=pflash,format=raw,file=" uboot )]
+      ["-drive" (.. "if=pflash,format=raw,file=" uboot )
+       "-drive" (.. "if=none,format=raw,id=hd0,file=" disk)
+       "-device" "virtio-blk-device,drive=hd0"
+       ]
       (let [cmdline (.. cmdline " mem=256M liminix mtdparts=phram0:16M(rootfs) phram.phram=phram0," options.phram-address ",16Mi,65536 root=/dev/mtdblock0")]
         ["-kernel" options.kernel "-append" cmdline])))
 
@@ -94,13 +99,13 @@
                      "-echr" "16"
                      "-device"
                      (.. "loader,file=" options.rootfs ",addr=" options.phram-address)
-
                      ])
            (appendm
             (if options.background
                 (background options.background)
                 ["-serial" "mon:stdio"]))
-           (appendm (bootable (or options.command-line "") options.u-boot))
+           (appendm (bootable (or options.command-line "")
+                              options.u-boot options.disk-image))
            (appendm (access-net))
            (appendm (local-net options.lan))
            (appendm ["-display" "none"])))
@@ -113,3 +118,4 @@
 
 (if options.rootfs (unlink options.rootfs))
 (if options.u-boot (unlink options.u-boot))
+(if options.disk-image (unlink options.disk-image))