tftpboot omnia using bootz not bootm

because kernel size is now beyond the u-boot size
limit for bootm

devices/turris-omnia/default.nix

@@ -14,7 +14,7 @@
     let openwrt = pkgs.openwrt; in {
           imports = [
             ../../modules/arch/arm.nix
-            ../../modules/outputs/tftpboot.nix
+            ../../modules/outputs/tftpbootlz.nix
             ../../modules/outputs/ext4fs.nix
             ../../modules/outputs/mbrimage.nix
             ../../modules/outputs/extlinux.nix
@@ -115,7 +115,9 @@
             };
           };
         };
-    boot.tftp.loadAddress = lim.parseInt "0x01800000";
+
+    boot.tftp.loadAddress = lim.parseInt "0x1000000";
+
     hardware = let
       mac80211 = pkgs.mac80211.override {
         drivers = ["ath9k_pci" "ath10k_pci"];
@@ -123,9 +125,9 @@
       };
       in {
         defaultOutput = "mtdimage";
-        loadAddress = lim.parseInt "0x00008000";
+        loadAddress = lim.parseInt "0x00800000"; # "0x00008000";
 
-        entryPoint = lim.parseInt "0x00008000";
+        entryPoint = lim.parseInt "0x00800000"; # "0x00008000";
         rootDevice = "/dev/mtdblock0";
         dts = {
           src = "${config.system.outputs.kernel.modulesupport}/arch/arm/boot/dts/armada-385-turris-omnia.dts";

modules/outputs/tftpbootlz.nix

@@ -0,0 +1,87 @@
+{
+  config
+, pkgs
+, lib
+, ...
+}:
+let
+  inherit (lib) mkOption types concatStringsSep;
+  inherit (pkgs.lib.trivial) toHexString;
+  o = config.system.outputs;
+  cmdline = concatStringsSep " " config.boot.commandLine;
+  cfg = config.boot.tftp;
+  boot-scr =
+    pkgs.buildPackages.runCommand "boot-scr" { nativeBuildInputs = [ pkgs.pkgsBuildBuild.dtc ];  } ''
+      uimageSize=$(($(stat -L -c %s ${o.zimage}) + 0x1000 &(~0xfff)))
+      rootfsStart=0x$(printf %x $((${toString cfg.loadAddress} + 0x100000 + $uimageSize   &(~0xfffff) )))
+      rootfsBytes=$(($(stat -L -c %s ${o.rootfs}) + 0x100000 &(~0xfffff)))
+      rootfsBytes=$(($rootfsBytes + ${toString cfg.freeSpaceBytes} ))
+      rootfsMb=$(($rootfsBytes >> 20))
+      cmd="mtdparts=phram0:''${rootfsMb}M(rootfs) phram.phram=phram0,''${rootfsStart},''${rootfsBytes},${toString config.hardware.flash.eraseBlockSize} root=/dev/mtdblock0";
+
+      dtbStart=$(printf %x $((${toString cfg.loadAddress} + $rootfsBytes + 0x100000 + $uimageSize )))
+
+      mkdir $out
+      cat ${o.dtb} > $out/dtb
+      fdtput -p -t s $out/dtb /reserved-memory/phram-rootfs compatible phram
+      fdtput -p -t lx $out/dtb /reserved-memory/phram-rootfs reg 0 $rootfsStart 0 $(printf %x $rootfsBytes)
+
+      dtbBytes=$(($(stat -L -c %s $out/dtb) + 0x1000 &(~0xfff)))
+
+      cat > $out/script << EOF
+      setenv serverip ${cfg.serverip}
+      setenv ipaddr ${cfg.ipaddr}
+      setenv bootargs 'liminix ${cmdline} $cmd'
+      tftpboot 0x${lib.toHexString cfg.loadAddress} result/zImage; tftpboot 0x$(printf %x $rootfsStart) result/rootfs ; tftpboot 0x$dtbStart result/dtb
+      setexpr bootaddr 0x$dtbStart + \$filesize
+      # lzmadec 0x${lib.toHexString cfg.loadAddress}  \$bootaddr
+      # bootz \$bootaddr - 0x$dtbStart
+      bootz 0x${lib.toHexString cfg.loadAddress} - 0x$dtbStart
+      EOF
+    '';
+in {
+  imports = [ ../ramdisk.nix ];
+  options.boot.tftp.freeSpaceBytes = mkOption {
+    type = types.int;
+    default = 0;
+  };
+  options.system.outputs = {
+    tftpbootlz = mkOption {
+      type = types.package;
+      description = ''
+        tftpbootlz
+        **********
+
+        This is a variant of the tftpboot output intended for the
+        Turris Omnia. It builds a uimage containing an uncompressed
+        kernel, then compresses the resulting image to be decompressed
+        using the u-boot lzmadec command. This is a workaround for an
+        awkwardly low CONFIG_SYS_BOOTM_LEN setting in the U-Boot build
+        for the device, which means that the regular tftpboot output
+        would only work for very small kernels.
+      '';
+    };
+  };
+  config = {
+    boot.ramdisk.enable = true;
+
+    system.outputs = {
+      tftpbootlz =
+        let
+          o = config.system.outputs; in
+          pkgs.runCommand "tftpboot" {
+            depsBuildBuild = [ pkgs.pkgsBuildBuild.lzma ];
+          } ''
+          mkdir $out
+          cd $out
+          ln -s ${o.rootfs} rootfs
+          ln -s ${o.zimage} zImage
+          ln -s ${o.manifest} manifest
+          ln -s ${o.kernel.headers} build
+          # lzma -c -z -9  < {uimage} > uimage.lz
+          ln -s ${boot-scr}/dtb dtb
+          ln -s ${boot-scr}/script boot.scr
+       '';
+    };
+  };
+}