From: Jozef Lawrynowicz <jozef.l@somniumtech.com>
Date: Tue, 29 Aug 2017 13:09:58 +0000 (+0100)
Subject: Fix simulation of MSP430's open system call.
X-Git-Url: http://git.efficios.com/?a=commitdiff_plain;h=3819af136deb7ba6bc2058d7848cf80b33dbe51c;p=deliverable%2Fbinutils-gdb.git

Fix simulation of MSP430's open system call.

	* sim/msp430/msp430-sim.c (maybe_perform_syscall): Fix passing of
	arguments for variadic syscall "open".
---

diff --git a/sim/msp430/ChangeLog b/sim/msp430/ChangeLog
index b78b96f831..d6634b4e79 100644
--- a/sim/msp430/ChangeLog
+++ b/sim/msp430/ChangeLog
@@ -1,3 +1,8 @@
+2017-08-29  Jozef Lawrynowicz  <jozef.l@somniumtech.com>
+
+	* sim/msp430/msp430-sim.c (maybe_perform_syscall): Fix passing of
+	arguments for variadic syscall "open".
+
 2016-08-15  Mike Frysinger  <vapier@gentoo.org>
 
 	* msp430-sim.c: Delete bfd.h include.
diff --git a/sim/msp430/msp430-sim.c b/sim/msp430/msp430-sim.c
index 93b47abc37..93a99162e5 100644
--- a/sim/msp430/msp430-sim.c
+++ b/sim/msp430/msp430-sim.c
@@ -278,7 +278,7 @@ static int
 get_op (SIM_DESC sd, MSP430_Opcode_Decoded *opc, int n)
 {
   MSP430_Opcode_Operand *op = opc->op + n;
-  int rv;
+  int rv = 0;
   int addr;
   unsigned char buf[4];
   int incval = 0;
@@ -465,7 +465,7 @@ static int
 put_op (SIM_DESC sd, MSP430_Opcode_Decoded *opc, int n, int val)
 {
   MSP430_Opcode_Operand *op = opc->op + n;
-  int rv;
+  int rv = 0;
   int addr;
   unsigned char buf[4];
   int incval = 0;
@@ -986,11 +986,26 @@ maybe_perform_syscall (SIM_DESC sd, int call_addr)
   if ((call_addr & ~0x3f) == 0x00180)
     {
       /* Syscall!  */
+      int arg1, arg2, arg3, arg4;
       int syscall_num = call_addr & 0x3f;
-      int arg1 = MSP430_CPU (sd)->state.regs[12];
-      int arg2 = MSP430_CPU (sd)->state.regs[13];
-      int arg3 = MSP430_CPU (sd)->state.regs[14];
-      int arg4 = MSP430_CPU (sd)->state.regs[15];
+
+      /* syscall_num == 2 is used for the variadic function "open".
+	 The arguments are set up differently for variadic functions.
+	 See slaa534.pdf distributed by TI.  */
+      if (syscall_num == 2)
+	{
+	  arg1 = MSP430_CPU (sd)->state.regs[12];
+	  arg2 = mem_get_val (sd, SP, 16);
+	  arg3 = mem_get_val (sd, SP + 2, 16);
+	  arg4 = mem_get_val (sd, SP + 4, 16);
+	}
+      else
+	{
+	  arg1 = MSP430_CPU (sd)->state.regs[12];
+	  arg2 = MSP430_CPU (sd)->state.regs[13];
+	  arg3 = MSP430_CPU (sd)->state.regs[14];
+	  arg4 = MSP430_CPU (sd)->state.regs[15];
+	}
 
       MSP430_CPU (sd)->state.regs[12] = sim_syscall (MSP430_CPU (sd),
 						     syscall_num, arg1, arg2,
@@ -1012,13 +1027,13 @@ msp430_step_once (SIM_DESC sd)
   MSP430_Opcode_Decoded opcode_buf;
   MSP430_Opcode_Decoded *opcode = &opcode_buf;
   int s1, s2, result;
-  int u1, u2, uresult;
-  int c, reg;
+  int u1 = 0, u2, uresult;
+  int c = 0, reg;
   int sp;
   int carry_to_use;
   int n_repeats;
   int rept;
-  int op_bytes, op_bits;
+  int op_bytes = 0, op_bits;
 
   PC &= 0xfffff;
   opcode_pc = PC;
@@ -1072,7 +1087,7 @@ msp430_step_once (SIM_DESC sd)
 
   if (TRACE_ANY_P (MSP430_CPU (sd)))
     trace_prefix (sd, MSP430_CPU (sd), NULL_CIA, opcode_pc,
-		  TRACE_LINENUM_P (MSP430_CPU (sd)), NULL, 0, "");
+		  TRACE_LINENUM_P (MSP430_CPU (sd)), NULL, 0, " ");
 
   TRACE_DISASM (MSP430_CPU (sd), opcode_pc);