diff --git a/phymem.go b/phymem.go
index f575935..64ccf5e 100644
--- a/phymem.go
+++ b/phymem.go
@@ -1,5 +1,6 @@
 // +build !windows
 // +build !linux
+// +build !freebsd
 
 package phymem
 
diff --git a/phymem_freebsd.go b/phymem_freebsd.go
new file mode 100644
index 0000000..d059e41
--- /dev/null
+++ b/phymem_freebsd.go
@@ -0,0 +1,38 @@
+package phymem
+
+// #include <stdio.h>
+// #include <unistd.h>
+// #include <sys/types.h>
+// #include <sys/sysctl.h>
+// #include <sys/param.h>
+// #include <sys/user.h>
+//
+//static segsz_t getRSS(void) {
+//    int mib[4];
+//    size_t len;
+//    struct kinfo_proc ki;
+//
+//    len = sizeof(mib) / sizeof(mib[0]);
+//    if (sysctlnametomib("kern.proc.pid", mib, &len) == -1) {
+//        return -1;
+//    }
+//    mib[3] = getpid();
+//    len = sizeof(ki);
+//    if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), &ki, &len, NULL, 0) == -1) {
+//        return -2;
+//    }
+//    return ki.ki_rssize;
+//}
+import "C"
+import "fmt"
+
+// for test.
+const providedCurrent = true
+
+func Current() (uint, error) {
+	rss := int(C.getRSS())
+	if rss < 0 {
+		return 0, fmt.Errorf("failed to get RSS via sysctl: %d", rss)
+	}
+	return uint(rss) * 4096, nil
+}