From 629914f65e7f9e8f0251b401a0966340557da91e Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Mon, 16 Oct 2023 19:55:17 +0100
Subject: [PATCH] initial support for ubifs

---
 devices/belkin-rt3200/default.nix | 15 ++++----
 modules/base.nix                  |  2 +-
 modules/standard.nix              |  1 +
 modules/ubifs.nix                 | 59 +++++++++++++++++++++++++++++++
 pkgs/systemconfig/default.nix     |  2 +-
 5 files changed, 71 insertions(+), 8 deletions(-)
 create mode 100644 modules/ubifs.nix

diff --git a/devices/belkin-rt3200/default.nix b/devices/belkin-rt3200/default.nix
index 7dd0f17a..248464ff 100644
--- a/devices/belkin-rt3200/default.nix
+++ b/devices/belkin-rt3200/default.nix
@@ -102,10 +102,7 @@
         MTD_SPI_NOR= "y";
         MTD_SPLIT_FIRMWARE= "y";
         MTD_SPLIT_FIT_FW= "y";
-        MTD_UBI="y";
-        MTD_UBI_BEB_LIMIT="20";
-        MTD_UBI_BLOCK="y";
-        MTD_UBI_WL_THRESHOLD="4096";
+
 
         MMC = "y";
         MMC_BLOCK = "y";
@@ -158,6 +155,12 @@
           klibBuild = config.system.outputs.kernel.modulesupport;
         };
       in {
+        ubi = {
+          minIOSize = "2048";
+          eraseBlockSize = "126976";
+          maxLEBcount = "1024"; # guessing
+        };
+
         defaultOutput = "flashimage";
         # the kernel expects this to be on a 2MB boundary. U-Boot
         # (I don't know why) has a default of 0x41080000, which isn't.
@@ -166,7 +169,7 @@
         # RAM unless the kernel is able to reuse it later. Oh well
         loadAddress = "0x42000000";
         entryPoint  = "0x42000000";
-        rootDevice = "/dev/mtdblock0";
+        rootDevice = "ubi0:liminix";
         dts = {
           src = "${openwrt.src}/target/linux/mediatek/dts/mt7622-linksys-e8450-ubi.dts";
           includes =  [
@@ -175,7 +178,7 @@
           ];
         };
 
-        flash.eraseBlockSize = "65536"; # c.f. pkgs/mips-vm/mips-vm.sh
+        flash.eraseBlockSize = "65536"; # this is probably wrong
         networkInterfaces =
           let
             inherit (config.system.service.network) link;
diff --git a/modules/base.nix b/modules/base.nix
index fb059d25..67d6ed74 100644
--- a/modules/base.nix
+++ b/modules/base.nix
@@ -39,7 +39,7 @@ in {
     };
     rootfsType =  mkOption {
       default = "squashfs";
-      type = types.enum ["squashfs" "jffs2"];
+      type = types.enum ["squashfs" "jffs2" "ubifs"];
     };
     boot = {
       commandLine = mkOption {
diff --git a/modules/standard.nix b/modules/standard.nix
index cb9b8ee0..c89017a7 100644
--- a/modules/standard.nix
+++ b/modules/standard.nix
@@ -7,5 +7,6 @@
     ./kexecboot.nix
     ./flashimage.nix
     ./jffs2.nix
+    ./ubifs.nix
   ];
 }
diff --git a/modules/ubifs.nix b/modules/ubifs.nix
new file mode 100644
index 00000000..4b8e190b
--- /dev/null
+++ b/modules/ubifs.nix
@@ -0,0 +1,59 @@
+{
+  config
+, pkgs
+, lib
+, ...
+}:
+let
+  inherit (lib) mkIf mkOption types;
+in
+{
+  imports = [
+    ./initramfs.nix
+  ];
+  options.system.outputs = {
+    systemConfiguration = mkOption {
+      type = types.package;
+      description = ''
+        pkgs.systemconfig for the configured filesystem,
+        contains 'activate' and 'init' commands
+      '';
+      internal = true;
+    };
+  };
+  options.hardware.ubi = {
+    minIOSize = mkOption { type = types.str; };
+    eraseBlockSize = mkOption { type = types.str; }; # LEB
+    maxLEBcount = mkOption { type = types.str; }; # LEB
+  };
+
+  config = mkIf (config.rootfsType == "ubifs") {
+    kernel.config = {
+      MTD_UBI="y";
+
+      UBIFS_FS = "y";
+      UBIFS_FS_SECURITY = "n";
+    };
+    boot.initramfs.enable = true;
+    system.outputs = rec {
+      systemConfiguration =
+        pkgs.systemconfig config.filesystem.contents;
+      rootfs =
+        let
+          inherit (pkgs.pkgsBuildBuild) runCommand mtdutils;
+          cfg = config.hardware.ubi;
+        in runCommand "mkfs.ubifs" {
+          depsBuildBuild = [ mtdutils ];
+        } ''
+          mkdir -p $TMPDIR/empty/nix/store/ $TMPDIR/empty/secrets
+          cp ${systemConfiguration}/bin/activate $TMPDIR/empty/activate
+          ln -s ${pkgs.s6-init-bin}/bin/init $TMPDIR/empty/init
+          mkdir -p $TMPDIR/empty/nix/store
+          for path in $(cat ${systemConfiguration}/etc/nix-store-paths) ; do
+            (cd $TMPDIR/empty && cp -a $path .$path)
+          done
+          mkfs.ubifs -x favor_lzo -c ${cfg.maxLEBcount} -m ${cfg.minIOSize} -e ${cfg.eraseBlockSize}  -y -r $TMPDIR/empty --output $out  --squash-uids -o $out
+        '';
+    };
+  };
+}
diff --git a/pkgs/systemconfig/default.nix b/pkgs/systemconfig/default.nix
index d229fdf5..a18800e3 100644
--- a/pkgs/systemconfig/default.nix
+++ b/pkgs/systemconfig/default.nix
@@ -68,7 +68,7 @@ in attrset:
     src = ./.;
 
     CFLAGS = "-Os";
-    LDFLAGS  = "-static";
+    LDFLAGS  = "-static -Xlinker -static";
 
     postConfigure = ''
       cp ${makedevs} makedevs.c