Changeset 5201199 in mainline

Timestamp:

2006-03-24T12:17:22Z (19 years ago)

Author:

Ondrej Palkovsky <ondrap@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

4037847

Parents:

11cb08ca

Message:

Fix bad order of EPC & STATUS change in syscall_shortcut.

Location:

arch/mips32/src

Files:

• exception.c (modified) (1 diff)
• start.S (modified) (2 diffs)

arch/mips32/src/exception.c

@@ -90 +90 @@
                 istate->epc += 4;
                 istate->v1 = istate->k1;
-        } else {
-                print_regdump(istate);
-                panic("reserved instruction");
-        }
+        } else 
+                unhandled_exception(n, istate);
 }
 

arch/mips32/src/start.S

@@ -252 +252 @@
         mtc0 $t0, $status
 
+        # CALL Syscall handler
         jal syscall_handler
         sw $v0, SS_ARG4($sp)        # save v0 - arg4 to stack
 
-        # restore epc+4
-        lw $t0,SS_EPC($sp)
-        addi $t0, $t0, 4
-        mtc0 $t0, $epc
-        
         # restore status
         mfc0 $t0, $status
         lw $t1,SS_STATUS($sp)
 
+        # Change back to EXL=1(from last exception), otherwise
+        # an interrupt could rewrite the CP0-EPC
         li $t2, ~REG_SAVE_MASK      # Mask UM,EXL,ERL,IE
         and $t0, $t0, $t2
@@ -269 +267 @@
         mtc0 $t0, $status
                         
+        # restore epc+4
+        lw $t0,SS_EPC($sp)
+        addi $t0, $t0, 4
+        mtc0 $t0, $epc
+        
         lw $sp,SS_SP($sp) # restore sp