jffs, kexecboot

Older uboot versions don't have an option to
override the DTB from the `mboot` command, so
the updated DTB needs to be replaced in the image
itself.

ci.nix

@@ -11,6 +11,7 @@ let
   devices = [
     "gl-ar750" "gl-mt300n-v2" "gl-mt300a"
     "qemu" "qemu-aarch64" "qemu-armv7l"
+    "tp-archer-ax23"
   ];
   vanilla = ./vanilla-configuration.nix;
   for-device = name:

devices/tp-archer-ax23/default.nix

@@ -46,7 +46,8 @@
       imports = [
         ../../modules/arch/mipsel.nix
         ../../modules/outputs/tftpboot.nix
-        ../../modules/outputs/tplink.nix
+        ../../modules/outputs/tplink-safeloader.nix
+        ../../modules/outputs/jffs2.nix
       ];
       config = {
         kernel = {
@@ -326,15 +327,10 @@
           MT7621_WDT = "y";  # or it might be this one
         };
         };
-        tplink.board = "ARCHER-AX23-V1";
+        tplink-safeloader.board = "ARCHER-AX23-V1";
         boot = {
           commandLine = [ "console=ttyS0,115200" ];
           tftp = {
-            # IP addresses to use in the boot monitor when flashing/ booting
-            # over TFTP. If you are flashing using the stock firmware's Web UI
-            # then these dummy values are fine
-            ipaddr = "192.168.0.1"; # router address
-            serverip = "192.168.0.5"; # build machine or other tftp server
             # Should be a segment of free RAM, where the tftp artifact
             # can be stored before unpacking it to the 'hardware.loadAddress'
             # The 'hardware.loadAddress' is 0x80001000, which suggests the
@@ -342,6 +338,8 @@
             # to 0x8800000. Let's put it at the 100MB mark at
             # 0x8000000+0x0640000=0x86400000
             loadAddress = lim.parseInt "0x86400000";
+            compressRoot = true;
+            replaceDtb = true;
           };
         };
         filesystem =
@@ -397,12 +395,12 @@
             address = lim.parseInt "0xbc040000";
             # 0x000000040000-0x000000fa0000
             size = lim.parseInt "0xf60000";
-            # guessed:
+            # TODO: find in /proc/mtd on a running system
             eraseBlockSize = 65536;
           };
 
           # since this is mentioned in the partition table as well?
-          defaultOutput = "tplink";
+          defaultOutput = "tplink-safeloader";
           # taken from openwrt sysupgrade image:
           # openwrt-23.05.2-ramips-mt7621-tplink_archer-ax23-v1-squashfs-sysupgrade.bin: u-boot legacy uImage, MIPS OpenWrt Linux-5.15.137, Linux/MIPS, OS Kernel Image (lzma), 2797386 bytes, Tue Nov 14 13:38:11 2023, Load Address: 0X80001000, Entry Point: 0X80001000, Header CRC: 0X19F74C5B, Data CRC: 0XF685563C
           loadAddress = lim.parseInt "0x80001000";

examples/ax23-extneder.nix

@@ -24,10 +24,16 @@ in rec {
     ../modules/ssh
     ../modules/bridge
     ../modules/hostapd
+    ../modules/outputs/kexecboot.nix
   ];
 
   hostname = "yardbird";
 
+  boot.tftp = {
+    serverip = "192.168.0.1";
+    ipaddr = "192.168.0.2";
+  };
+
   services.hostap = svc.hostapd.build {
     interface = config.hardware.networkInterfaces.wlan;
     params = {
@@ -144,7 +150,10 @@ in rec {
   users.root = secrets.root;
 
   defaultProfile.packages = with pkgs; [
-    figlet
-    #tcpdump
+    tcpdump
+    # for arp
+    nettools
+    # for kexec booting
+    gnutar
   ];
 }

modules/outputs.nix

@@ -60,7 +60,7 @@ in
           Combined kernel and FDT in uImage (U-Boot compatible) format
         '';
       };
-      tplink = mkOption {
+      tplink-safeloader = mkOption {
         type = types.package;
       };
       u-boot = mkOption {

modules/outputs/tftpboot.nix

@@ -22,6 +22,16 @@ in {
       type = types.bool;
       default = false;
     };
+    replaceDtb = mkOption {
+      description = ''
+        Replace DTB instead of overriding it.
+
+        Useful for older versions of uboot that don't support
+        overriding the DTB from the bootm/bootz command line.
+      '';
+      type = types.bool;
+      default = false;
+    };
   };
   options.system.outputs = {
     tftpboot = mkOption {
@@ -63,8 +73,13 @@ in {
             zimage = "bootz";
           }; in choices.${cfg.kernelFormat};
           cmdline = concatStringsSep " " config.boot.commandLine;
+          objcopy = "${pkgs.stdenv.cc.bintools.targetPrefix}objcopy";
+          stripAndZip = ''
+            ${objcopy} -O binary -R .reginfo -R .notes -R .note -R .comment -R .mdebug -R .note.gnu.build-id -S vmlinux.elf vmlinux.bin
+            rm -f vmlinux.bin.lzma ; lzma -k -z  vmlinux.bin
+          '';
         in
-          pkgs.runCommand "tftpboot" { nativeBuildInputs = with pkgs.pkgsBuildBuild; [ lzma dtc ];  } ''
+          pkgs.runCommand "tftpboot" { nativeBuildInputs = with pkgs.pkgsBuildBuild; [ lzma dtc pkgs.stdenv.cc ubootTools ];  } ''
             mkdir $out
             cd $out
             binsize() { local s=$(stat -L -c %s $1); echo $(($s + 0x1000 &(~0xfff))); }
@@ -77,12 +92,19 @@ in {
             imageSize=$(binsize ${image})
 
             ln -s ${o.manifest} manifest
-            ln -s ${image} image
             ln -s ${o.kernel} vmlinux  # handy for gdb
 
+            ${if cfg.compressRoot && cfg.replaceDtb
+              then ''
+                echo "Having both compressRoot and replaceDtb enabled is not currently supported"
+                exit 1
+              '' else ""
+            }
+
             ${if cfg.compressRoot
               then ''
                 lzma -z9cv ${o.rootfs} > rootfs.lz
+                # TODO this is no longer correct
                 rootfsLzStart=$(($imageStart + $imageSize))
                 rootfsLzSize=$(binsize rootfs.lz)
               ''
@@ -107,6 +129,13 @@ in {
             cmd="liminix ${cmdline} mtdparts=phram0:''${rootfsSize}(rootfs) phram.phram=phram0,''${rootfsStart},''${rootfsSize},${toString config.hardware.flash.eraseBlockSize} root=/dev/mtdblock0";
             fdtput -t s dtb /chosen bootargs "$cmd"
 
+            # re-package image with updated dtb
+            cp ${o.kernel} vmlinux.elf; chmod +w vmlinux.elf
+            ${objcopy} --update-section .appended_dtb=dtb vmlinux.elf
+            ${stripAndZip}
+            # TODO don't hardcode mips, entryPoint, loadAddress, name
+            mkimage -A mips -O linux -T kernel -C lzma -a 0x80001000 -e 0x80001000 -n 'MIPS Liminix Linux' -d vmlinux.bin.lzma image
+
             # dtc -I dtb -O dts -o /dev/stdout dtb | grep -A10 chosen ; exit 1
 
             cat > boot.scr << EOF

modules/outputs/tplink-safeloader.nix

@@ -7,19 +7,19 @@
 let
   inherit (lib) mkOption types concatStringsSep;
   o = config.system.outputs;
-  cfg = config.tplink;
+  cfg = config.tplink-safeloader;
 in {
-  options.tplink = {
+  options.tplink-safeloader = {
     board = mkOption {
       type = types.str;
     };
   };
   options.system.outputs = {
-    tplink = mkOption {
+    tplink-safeloader = mkOption {
       type = types.package;
       description = ''
-        tplink
-        ******
+        tplink-safeloader
+        *****************
 
         For creating 'safeloader' images for tp-link devices.
 
@@ -52,7 +52,7 @@ in {
   };
   config = {
     system.outputs = rec {
-      tplink = 
+      tplink-safeloader =
         pkgs.runCommand "tplink" { nativeBuildInputs = with pkgs.pkgsBuildBuild; [ firmware-utils ];  } ''
         tplink-safeloader -B "${cfg.board}" -k "${o.uimage}" -r "${o.rootfs}" -o $out
         '';