Decent multiarch with make O=

rungdb

@@ -21,9 +21,10 @@ else
   brk=""
 fi
 
-gdb="$(pwd)/buildroot/output/host/usr/bin/${arch}-linux-gdb"
-cd buildroot/output/build/linux-?.*.*/
-if $kgdb; then
+buildroot_out_dir="$(pwd)/buildroot/output.${arch}~"
+gdb="${buildroot_out_dir}/host/usr/bin/${arch}-linux-gdb"
+cd "${buildroot_out_dir}/build"/linux-?.*.*/
+if "$kgdb"; then
     cmd="$gdb \
       -q \
       -ex 'add-auto-load-safe-path $(pwd)' \
@@ -32,7 +33,7 @@ if $kgdb; then
     "
 else
   case "$arch" in
-    x86_64)
+    'x86_64')
       # http://stackoverflow.com/questions/11408041/how-to-debug-the-linux-kernel-with-gdb-and-qemu/33203642#33203642
       # http://stackoverflow.com/questions/4943857/linux-kernel-live-debugging-how-its-done-and-what-tools-are-used/42316607#42316607
       # http://stackoverflow.com/questions/28607538/how-to-debug-linux-kernel-modules-with-qemu/44095831#44095831
@@ -50,7 +51,7 @@ else
         -ex 'lx-symbols ../kernel_module-1.0/'
       "
       ;;
-    arm)
+    'arm')
       cmd="$gdb \
         -q \
         -ex 'add-auto-load-safe-path $(pwd)' \