add tftpboot test for mips

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/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/test.nix

@@ -30,6 +30,7 @@ run-liminix-vm \
 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";
 }