add tftpboot test for mips

This is for MIPS.  I spent a while investigating why the second virtio
net device doesn't function in qemu mips malta u-boot, but with no
success. Use the first one instead.

devices/families/qemu.nix

@@ -33,7 +33,7 @@
       in {
         defaultOutput = "vmroot";
         rootDevice = "/dev/mtdblock0";
-        dts.src = null;
+        dts.src = pkgs.lib.mkDefault null;
         flash.eraseBlockSize = 65536;
         networkInterfaces =
           let inherit (config.system.service.network) link;

devices/qemu/default.nix

@@ -36,7 +36,7 @@
     in the Development manual.
 
   '';
-  module = {pkgs, config, lim, ... }: {
+  module = {pkgs, config, lib, lim, ... }: {
     imports = [
       ../../modules/arch/mipseb.nix
       ../families/qemu.nix
@@ -50,5 +50,24 @@
         SERIAL_8250_CONSOLE= "y";
       };
     };
+    hardware =
+      # from arch/mips/mti-malta/Platform:load-$(CONFIG_MIPS_MALTA)  += 0xffffffff80100000
+      let addr = lim.parseInt "0x80100000";
+      in {
+        loadAddress = addr;
+        entryPoint = addr;
+
+        # Unlike the arm qemu targets, we need a static dts when
+        # running u-boot-using tests, qemu dumpdtb command doesn't
+        # work for this board. I am not at all sure this dts is
+        # *correct* but it does at least boot
+        dts = lib.mkForce {
+          src = "${config.system.outputs.kernel.modulesupport}/arch/mips/boot/dts/mti/malta.dts";
+          includes =  [
+            "${config.system.outputs.kernel.modulesupport}/arch/mips/boot/dts/"
+          ];
+        };
+
+      };
   };
 }

overlay.nix

@@ -224,6 +224,34 @@ extraPkgs // {
     '';
   };
 
+  ubootQemuMips = final.buildUBoot {
+    defconfig = "malta_defconfig";
+    extraMeta.platforms = ["mips-linux"];
+    filesToInstall = ["u-boot.bin"];
+    # define the prompt to be the same as arm{32,64} so
+    # we can use the same expect script for both
+    extraPatches = [ ./pkgs/u-boot/0002-virtio-init-for-malta.patch ];
+    extraConfig = ''
+      CONFIG_SYS_PROMPT="=> "
+      CONFIG_VIRTIO=y
+      CONFIG_AUTOBOOT=y
+      CONFIG_DM_PCI=y
+      CONFIG_VIRTIO_PCI=y
+      CONFIG_VIRTIO_NET=y
+      CONFIG_VIRTIO_BLK=y
+      CONFIG_VIRTIO_MMIO=y
+      CONFIG_QFW_MMIO=y
+      CONFIG_FIT=y
+      CONFIG_LZMA=y
+      CONFIG_CMD_LZMADEC=y
+      CONFIG_SYS_BOOTM_LEN=0x1000000
+      CONFIG_SYS_MALLOC_LEN=0x400000
+      CONFIG_MIPS_BOOT_FDT=y
+      CONFIG_OF_LIBFDT=y
+      CONFIG_OF_STDOUT_VIA_ALIAS=y
+   '';
+  };
+
   # gnufdisk = prev.gnufdisk.override {
   #   guile = null;
   # };

pkgs/kernel/default.nix

@@ -51,6 +51,7 @@ stdenv.mkDerivation rec {
   patches = [
     ./cmdline-cookie.patch
     ./phram-allow-cached-mappings.patch
+    ./mips-malta-fdt-from-bootloader.patch
   ];
 
   # this is here to work around what I think is a bug in nixpkgs

pkgs/kernel/mips-malta-fdt-from-bootloader.patch

@@ -0,0 +1,18 @@
+diff --git a/arch/mips/mti-malta/malta-setup.c b/arch/mips/mti-malta/malta-setup.c
+index 21cb3ac1237b..f11409ae9583 100644
+--- a/arch/mips/mti-malta/malta-setup.c
++++ b/arch/mips/mti-malta/malta-setup.c
+@@ -192,7 +192,12 @@ static void __init bonito_quirks_setup(void)
+ 
+ void __init *plat_get_fdt(void)
+ {
+-	return (void *)__dtb_start;
++    void *r=0;
++    if(fw_arg0 == -2)
++	r = (void *) KSEG1ADDR(fw_arg1);
++    else
++	r = (void *)  __dtb_start;
++    return r;
+ }
+ 
+ void __init plat_mem_setup(void)

pkgs/run-liminix-vm/run-liminix-vm.fnl

@@ -36,20 +36,36 @@
   (match args
     ["--background" dir & rest] (assoc (parse-args rest) :background dir)
     ["--u-boot" bin & rest]
-    (assoc (parse-args rest) :u-boot (pad-file bin (* 64 1024) "\xff"))
+    (assoc (parse-args rest) :u-boot bin)
     ["--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)
+    ["--wan" spec & rest] (assoc (parse-args rest) :wan spec)
     ["--command-line" cmd & rest] (assoc (parse-args rest) :command-line cmd)
     [kernel rootfsimg]
     { :kernel kernel :rootfs (pad-file rootfsimg (* 16 1024)) }
     ))
 
+(fn pad-u-boot [options]
+  (if options.u-boot
+      (let [size (.
+                  {
+                   :mips (* 4 1024)
+                   :aarch64 (* 64 1024)
+                   :arm (* 64 1024)
+                   }
+                  options.arch)]
+        (assoc options
+               :u-boot
+               (pad-file options.u-boot size "\xff")))
+      options))
+
 (local options
        (assert
-        (merge { :arch "mips" } (parse-args arg))
+        (pad-u-boot
+         (merge { :arch "mips" } (parse-args arg)))
         (.. "Usage: " (. arg 0) " blah bah")))
 
 (fn background [dir]
@@ -61,9 +77,11 @@
      "-serial" (.. "unix:" sock ",server,nowait")
      "-monitor" (.. "unix:" monitor ",server,nowait")]))
 
-(fn access-net []
+(fn access-net [override]
   [
-   "-netdev" "socket,id=access,mcast=230.0.0.1:1234,localaddr=127.0.0.1"
+   "-netdev"  (.. (or override
+                      "socket,mcast=230.0.0.1:1234,localaddr=127.0.0.1")
+                  ",id=access")
    "-device" "virtio-net,disable-legacy=on,disable-modern=off,netdev=access,mac=ba:ad:1d:ea:21:02"
    ])
 
@@ -95,18 +113,21 @@
 (local exec-args
        (-> []
            (appendm (. bin options.arch))
-           (appendm ["-m" "272"
-                     "-echr" "16"
-                     "-device"
-                     (.. "loader,file=" options.rootfs ",addr=" options.phram-address)
-                     ])
+           (appendm ["-echr" "16"])
+           (appendm (if options.phram-address
+                        [
+                         "-m" "272"
+                         "-device"
+                         (.. "loader,file=" options.rootfs ",addr=" options.phram-address)
+                         ]
+                        ["-m" "256"]))
            (appendm
             (if options.background
                 (background options.background)
                 ["-serial" "mon:stdio"]))
            (appendm (bootable (or options.command-line "")
                               options.u-boot options.disk-image))
-           (appendm (access-net))
+           (appendm (access-net options.wan))
            (appendm (local-net options.lan))
            (appendm ["-display" "none"])))
 

pkgs/u-boot/0002-virtio-init-for-malta.patch

@@ -0,0 +1,15 @@
+diff --git a/board/imgtec/malta/malta.c b/board/imgtec/malta/malta.c
+index 9853a0ba82..d95e332d6d 100644
+--- a/board/imgtec/malta/malta.c
++++ b/board/imgtec/malta/malta.c
+@@ -169,7 +169,9 @@ int board_early_init_f(void)
+ int misc_init_r(void)
+ {
+ 	rtc_reset();
+-
++#if IS_ENABLED(CONFIG_VIRTIO)
++	virtio_init();
++#endif
+ 	return 0;
+ }
+ 

tests/tftpboot/configuration.nix

@@ -18,9 +18,17 @@ in {
     ../../modules/outputs/tftpboot.nix
   ];
   config = {
-    hardware.dts.src = lib.mkForce dts;
+    # use extracted dts if it was null in the device
+    # definition, use actual dts if provided
+    hardware.dts.src = lib.mkOverride 500 dts;
     boot.tftp = {
-      loadAddress = lim.parseInt "0x44000000";
+      loadAddress =
+        let offsets = {
+              mips = "0x88000000";
+              arm = "0x44000000";
+              aarch64 = "0x44000000";
+            };
+        in lim.parseInt offsets.${pkgs.stdenv.hostPlatform.qemuArch} ;
       serverip = "10.0.2.2";
       ipaddr = "10.0.2.15";
     };

tests/tftpboot/script.expect

@@ -1,10 +1,10 @@
 set timeout 30
 
 spawn socat unix-connect:vm/console -
-expect "stop autoboot"
-send "\r"
-expect "=>"
-send "setenv ethact eth1\r"
+expect {
+   "stop autoboot" { send "\r" }
+   "=>" { send "\r" }
+}
 set fh [open "result/boot.scr"]
 while {[gets $fh line] >= 0} {
       expect "=>"

tests/tftpboot/test.nix

@@ -9,7 +9,6 @@ let derivation = (import liminix {
     img = derivation.outputs.tftpboot;
     uboot = derivation.pkgs.${ubootName};
     pkgsBuild = derivation.pkgs.pkgsBuildBuild;
-    phram = 240 * 1024 * 1024;
 in pkgsBuild.runCommand "check" {
   nativeBuildInputs = with pkgsBuild; [
     expect
@@ -24,14 +23,14 @@ run-liminix-vm \
  --background ./vm \
  --u-boot ${uboot}/u-boot.bin \
  --arch ${derivation.pkgs.stdenv.hostPlatform.qemuArch} \
- --phram-address $(printf "0x%x" ${toString phram} ) \
- --lan "user,tftp=`pwd`" \
+ --wan "user,tftp=`pwd`" \
  --disk-image result/rootfs \
  result/uimage result/rootfs
 
 expect ${./script.expect} 2>&1 |tee $out
 '';
 in {
-  arm = check  "qemu-armv7l" "ubootQemuArm";
   aarch64 = check "qemu-aarch64" "ubootQemuAarch64";
+  arm = check  "qemu-armv7l" "ubootQemuArm";
+  mips = check  "qemu" "ubootQemuMips";
 }