sysgen: Cope with non-inline kernel build

When regenerating system call tables, cope with a local kernel tree where
the kernel has been built into a separate directory (with `make O=...`) rather
than inline.

So:
 - LINUX makefile var / -linux command line option give location of source tree
 - LINUXBLD makefile var / -linuxbld command line option gives location of
   built kernel

1 files changed, 5 insertions, 1 deletions

diff --git a/sysgen/sysgen.go b/sysgen/sysgen.go
index 7f5979c65..f52e12ab7 100644
--- a/sysgen/sysgen.go
+++ b/sysgen/sysgen.go
@@ -17,7 +17,8 @@ import (
 )
 
 var (
-	flagLinux = flag.String("linux", "", "path to linux kernel checkout")
+	flagLinux = flag.String("linux", "", "path to linux kernel source checkout")
+	flagLinuxBld = flag.String("linuxbld", "", "path to linux kernel build directory")
 )
 
 func main() {
@@ -25,6 +26,9 @@ func main() {
 	if *flagLinux == "" {
 		failf("provide path to linux kernel checkout via -linux flag (or make generate LINUX= flag)")
 	}
+	if *flagLinuxBld == "" {
+		flagLinuxBld = flagLinux
+	}
 	if len(flag.Args()) == 0 {
 		failf("usage: sysgen -linux=linux_checkout input_file")
 	}