diff --git a/boot-qemu.py b/boot-qemu.py
index 63b77ec..187d9f2 100755
--- a/boot-qemu.py
+++ b/boot-qemu.py
@@ -195,7 +195,7 @@ def get_smp_value(args):
 
     # Use the minimum of the number of usable processors for the script or
     # CONFIG_NR_CPUS.
-    usable_cpus = len(os.sched_getaffinity(0))
+    usable_cpus = os.cpu_count()
     return min(usable_cpus, config_nr_cpus)
 
 
@@ -326,7 +326,7 @@ def get_linux_ver_code(decomp_cmd):
                              input=decomp.stdout)
 
     linux_version = None
-    for line in strings.stdout.decode("UTF-8").split("\n"):
+    for line in strings.stdout.decode("UTF-8", "ignore").split("\n"):
         if re.search(r"Linux version \d+\.\d+\.\d+", line):
             linux_version = re.search(r"\d+\.\d+\.\d+", line)[0].split(".")
             break