Implement simple option to override grub-i386 dirs

For people with some weird hipster-OS which doesn't have a `/usr/lib`
the current script breaks. Allowing to override the path with an
environment variable seems to be the easiest way to solve this issue for
now.

2 files changed, 9 insertions, 4 deletions

diff --git a/kernel/build.sh b/kernel/build.sh
index bf8c971..9d48229 100755
--- a/kernel/build.sh
+++ b/kernel/build.sh
@@ -9,7 +9,8 @@ GRUB_CFG_PATH="src/grub.cfg"
 ARCH="x86_64"
 TARGET="$ARCH-uff"
 RUST_BIN="$TARGET_PATH/$TARGET/debug/libkernel.a"
-QUEMU="qemu-system-x86_64 -cdrom $TARGET_PATH/uff.iso"
+QEMU="qemu-system-x86_64 -cdrom $TARGET_PATH/uff.iso"
+GRUB_i386="${GRUB_i386:-/usr/lib/grub/i386-pc}"
 
 cleanup_target() {
     rm -f $TARGET_PATH/uff.iso &> /dev/null
@@ -48,7 +49,8 @@ build_kernel_iso() {
     mkdir $TMP_PATH/isofiles/boot/grub &> /dev/null
     cp $TARGET_PATH/kernel.bin $TMP_PATH/isofiles/boot &> /dev/null
     cp $GRUB_CFG_PATH $TMP_PATH/isofiles/boot/grub/grub.cfg &> /dev/null
-    grub-mkrescue -d /usr/lib/grub/i386-pc -o $TARGET_PATH/uff.iso $TMP_PATH/isofiles
+    [ -d "$GRUB_i386" ] || { echo "Grub img $GRUB_i386 does not exist!"; exit 1; }
+    grub-mkrescue -d "$GRUB_i386" -o $TARGET_PATH/uff.iso $TMP_PATH/isofiles
     cleanup_temp
 }
 
@@ -57,11 +59,11 @@ build_init() {
 }
 
 build_launch() {
-    $QUEMU
+    $QEMU
 }
 
 build_launch_serial() {
-    $QUEMU -device isa-debug-exit,iobase=0xf4,iosize=0x04 -serial stdio #-display none
+    $QEMU -device isa-debug-exit,iobase=0xf4,iosize=0x04 -serial stdio #-display none
 }
 
 build_run() {
diff --git a/kernel/shell.nix b/kernel/shell.nix
index ba2647a..4fc72af 100644
--- a/kernel/shell.nix
+++ b/kernel/shell.nix
@@ -2,4 +2,7 @@ with import <nixpkgs> { };
 mkShell {
   name = "uff-os";
   buildInputs = [ rustup nasm grub2 cargo-xbuild gcc xorriso ];
+  shellHook = ''
+    export GRUB_i386="${grub2}/lib/grub/i386-pc"
+  '';
 }