1 files changed, 26 insertions, 0 deletions
diff --git a/user/libthread/thread_fork.S b/user/libthread/thread_fork.S
new file mode 100644
index 0000000..143f17b
--- /dev/null
+++ b/user/libthread/thread_fork.S
@@ -0,0 +1,26 @@
+#include <syscall_int.h>
+
+// int thread_fork(tcb_t* tcb,
+//                 void* (*f)(void*),
+//                 void* args);
+.global thread_fork
+.type thread_fork, %function
+thread_fork:
+    mov 0x4(%esp), %edi   // tcb
+    mov 0x8(%esp), %esi   // f
+    mov 0xc(%esp), %edx   // arg
+    int $THREAD_FORK_INT
+    cmp $0, %eax
+    jne .parent           // both failure and success returns non-zero for parent
+    mov 0x8(%edi), %esp   // read tcb.stack_hi and set stack
+    push %edx
+    push %esi
+    call thr_begin        // thread entry point and this will not return
+.parent:
+    ret
+
+.global get_esp
+.type get_esp, %function
+get_esp:
+    lea -0x4(%esp), %eax
+    ret