init: init nachos hw01, should pass jenkins os_group_20_hw job but fail on os_group_20_ta job

code/test/start.S

@@ -0,0 +1,196 @@
+/* Start.s 
+ *	Assembly language assist for user programs running on top of Nachos.
+ *
+ *	Since we don't want to pull in the entire C library, we define
+ *	what we need for a user program here, namely Start and the system
+ *	calls.
+ */
+
+#define IN_ASM
+#include "syscall.h"
+
+        .text   
+        .align  2
+
+/* -------------------------------------------------------------
+ * __start
+ *	Initialize running a C program, by calling "main". 
+ *
+ * 	NOTE: This has to be first, so that it gets loaded at location 0.
+ *	The Nachos kernel always starts a program by jumping to location 0.
+ * -------------------------------------------------------------
+ */
+
+	.globl __start
+	.ent	__start
+__start:
+	jal	main
+	move	$4,$0		
+	jal	Exit	 /* if we return from main, exit(0) */
+	.end __start
+
+/* -------------------------------------------------------------
+ * System call stubs:
+ *	Assembly language assist to make system calls to the Nachos kernel.
+ *	There is one stub per system call, that places the code for the
+ *	system call into register r2, and leaves the arguments to the
+ *	system call alone (in other words, arg1 is in r4, arg2 is 
+ *	in r5, arg3 is in r6, arg4 is in r7)
+ *
+ * 	The return value is in r2. This follows the standard C calling
+ * 	convention on the MIPS.
+ * -------------------------------------------------------------
+ */
+
+	.globl Halt
+	.ent	Halt
+Halt:
+	addiu $2,$0,SC_Halt
+	syscall
+	j	$31
+	.end Halt
+
+	.globl MSG
+	.ent   MSG
+MSG:
+	addiu $2,$0,SC_MSG
+	syscall
+	j	$31
+	.end MSG
+
+	.globl Add
+	.ent	Add
+Add:
+	addiu $2,$0,SC_Add
+	syscall
+	j 	$31
+	.end Add
+
+	.globl Exit
+	.ent	Exit
+Exit:
+	addiu $2,$0,SC_Exit
+	syscall
+	j	$31
+	.end Exit
+
+	.globl Exec
+	.ent	Exec
+Exec:
+	addiu $2,$0,SC_Exec
+	syscall
+	j	$31
+	.end Exec
+
+	.globl ExecV
+	.ent	ExecV
+ExecV:
+	addiu $2,$0,SC_ExecV
+	syscall
+	j	$31
+	.end ExecV
+
+	.globl Join
+	.ent	Join
+Join:
+	addiu $2,$0,SC_Join
+	syscall
+	j	$31
+	.end Join
+
+	.globl Create
+	.ent	Create
+Create:
+	addiu $2,$0,SC_Create
+	syscall
+	j	$31
+	.end Create
+
+	.globl Remove
+	.ent	Remove
+Remove:
+	addiu $2,$0,SC_Remove
+	syscall
+	j	$31
+	.end Remove
+
+	.globl Open
+	.ent	Open
+Open:
+	addiu $2,$0,SC_Open
+	syscall
+	j	$31
+	.end Open
+
+	.globl Read
+	.ent	Read
+Read:
+	addiu $2,$0,SC_Read
+	syscall
+	j	$31
+	.end Read
+
+	.globl Write
+	.ent	Write
+Write:
+	addiu $2,$0,SC_Write
+	syscall
+	j	$31
+	.end Write
+
+	.globl Close
+	.ent	Close
+Close:
+	addiu $2,$0,SC_Close
+	syscall
+	j	$31
+	.end Close
+
+	.globl Seek
+	.ent	Seek
+Seek:
+	addiu $2,$0,SC_Seek
+	syscall
+	j	$31
+	.end Seek
+
+        .globl ThreadFork
+        .ent    ThreadFork
+ThreadFork:
+        addiu $2,$0,SC_ThreadFork
+        syscall
+        j       $31
+        .end ThreadFork
+
+        .globl ThreadYield
+        .ent    ThreadYield
+ThreadYield:
+        addiu $2,$0,SC_ThreadYield
+        syscall
+        j       $31
+        .end ThreadYield
+
+	.globl ThreadExit
+	.ent    ThreadExit
+ThreadExit:
+	addiu $2, $0, SC_ThreadExit
+	syscall
+	j 	$31
+	.end ThreadExit
+
+	.globl ThreadJoin
+	.ent    ThreadJoin
+ThreadJoin:
+	addiu $2, $0, SC_ThreadJoin
+	syscall
+	j 	$31
+	.end ThreadJoin
+
+
+/* dummy function to keep gcc happy */
+        .globl  __main
+        .ent    __main
+__main:
+        j       $31
+        .end    __main
+