1 files changed, 27 insertions, 7 deletions

diff --git a/gnu/build/vm.scm b/gnu/build/vm.scm
index ed84463677..8f8ca609f2 100644
--- a/gnu/build/vm.scm
+++ b/gnu/build/vm.scm
@@ -77,6 +77,7 @@
                            linux initrd
                            make-disk-image?
                            single-file-output?
+                           target-arm32?
                            (disk-image-size (* 100 (expt 2 20)))
                            (disk-image-format "qcow2")
                            (references-graphs '()))
@@ -91,6 +92,31 @@ access it via /dev/hda.
 
 REFERENCES-GRAPHS can specify a list of reference-graph files as produced by
 the #:references-graphs parameter of 'derivation'."
+
+  (define arch-specific-flags
+    `(;; On ARM, a machine has to be specified. Use "virt" machine to avoid
+      ;; hardware limits imposed by other machines.
+      ,@(if target-arm32? '("-M" "virt") '())
+
+      ;; Only enable kvm if we see /dev/kvm exists.  This allows users without
+      ;; hardware virtualization to still use these commands.  KVM support is
+      ;; still buggy on some ARM32 boards. Do not use it even if available.
+      ,@(if (and (file-exists? "/dev/kvm")
+                 (not target-arm32?))
+            '("-enable-kvm")
+            '())
+      "-append"
+      ;; The serial port name differs between emulated architectures/machines.
+      ,@(if target-arm32?
+            `(,(string-append "console=ttyAMA0 --load=" builder))
+            `(,(string-append "console=ttyS0 --load=" builder)))
+      ;; NIC is not supported on ARM "virt" machine, so use a user mode
+      ;; network stack instead.
+      ,@(if target-arm32?
+            '("-device" "virtio-net-pci,netdev=mynet"
+              "-netdev" "user,id=mynet")
+            '("-net" "nic,model=virtio"))))
+
   (when make-disk-image?
     (format #t "creating ~a image of ~,2f MiB...~%"
             disk-image-format (/ disk-image-size (expt 2 20)))
@@ -113,7 +139,6 @@ the #:references-graphs parameter of 'derivation'."
   (unless (zero?
            (apply system* qemu "-nographic" "-no-reboot"
                   "-m" (number->string memory-size)
-                  "-net" "nic,model=virtio"
                   "-virtfs"
                   (string-append "local,id=store_dev,path="
                                  (%store-directory)
@@ -132,12 +157,7 @@ the #:references-graphs parameter of 'derivation'."
                                                   ",format=" disk-image-format
                                                   ",id=myhd"))
                        '())
-                   ;; Only enable kvm if we see /dev/kvm exists.
-                   ;; This allows users without hardware virtualization to still
-                   ;; use these commands.
-                   (if (file-exists? "/dev/kvm")
-                       '("-enable-kvm")
-                       '()))))
+                   arch-specific-flags)))
     (error "qemu failed" qemu))
 
   ;; When MAKE-DISK-IMAGE? is true, the image is in OUTPUT already.