vm: use a stripped vmlinux

This reduces the combined image from 9.1G to 7.2G, and also gets us
away from using the vmlinux from dev, which we wouldn't be able to do
on aarch64 anyway.

Signed-off-by: Alyssa Ross <hi@alyssa.is>

1 files changed, 13 insertions, 3 deletions

diff --git a/img/app/default.nix b/img/app/default.nix
index 194c590..3073a0e 100644
--- a/img/app/default.nix
+++ b/img/app/default.nix
@@ -51,7 +51,7 @@ let
         -T ${writeReferencesToFile packagesSysroot} .
   '';
 
-  kernel = buildPackages.linux.override {
+  kernel = (buildPackages.linux_latest.override {
     structuredExtraConfig = with lib.kernel; {
       VIRTIO = yes;
       VIRTIO_PCI = yes;
@@ -59,7 +59,17 @@ let
       VIRTIO_CONSOLE = yes;
       EXT4_FS = yes;
     };
-  };
+  }).overrideAttrs ({ installFlags ? [], ... }: {
+    installFlags = installFlags ++ [
+      # vmlinux.bin is the stripped version of vmlinux.
+      # Confusingly, compressed/vmlinux.bin is the stripped version of
+      # the top-level vmlinux target, while the top-level vmlinux.bin
+      # is the stripped version of compressed/vmlinux.  So we use
+      # compressed/vmlinux.bin, since we want a stripped version of
+      # the kernel that *hasn't* been built to be compressed.  Weird!
+      "KBUILD_IMAGE=$(boot)/compressed/vmlinux.bin"
+    ];
+  });
 in
 
 stdenvNoCC.mkDerivation {
@@ -71,7 +81,7 @@ stdenvNoCC.mkDerivation {
   nativeBuildInputs = [ jq lseek s6-rc tar2ext4 util-linux ];
 
   PACKAGES_TAR = packagesTar;
-  KERNEL = "${kernel.dev}/vmlinux";
+  KERNEL = "${kernel}/vmlinux.bin";
 
   makeFlags = [ "prefix=$(out)" ];