1 files changed, 40 insertions, 0 deletions
diff --git a/software/smp/smp.c b/software/smp/smp.c
new file mode 100644
index 0000000..36c9db9
--- /dev/null
+++ b/software/smp/smp.c
@@ -0,0 +1,40 @@
+#include <stdio.h>
+#include <unistd.h>
+#include "atomic.h"
+void write_hex(int, unsigned long);
+
+atomic_t tty_lock = ATOMIC_INIT(0);
+
+void get_lock(atomic_t *lock)
+{
+  while (atomic_xchg(lock, 1) == 1);
+  mb();
+}
+
+void put_lock(atomic_t *lock)
+{
+  mb();
+  atomic_xchg(lock, 0);
+}
+
+int secondary_main(int hartid)
+{
+  volatile int counter;
+
+  while (1) {
+    get_lock(&tty_lock);
+    write(1, "hello world from hart ", 22);
+    char s[] = {'0', '\n', '\0'};
+    s[0] += hartid;
+    write(1, s, 2);
+    put_lock(&tty_lock);
+
+    for (counter = 0; counter < 10000 + 100*hartid; ++counter)
+        mb();
+  }
+}
+
+int main()
+{
+  return secondary_main(0);
+}