Only run sancus-step initialization once

sancus-tee · Oct 17, 2019 · e06c186 · e06c186
1 parent e954682
commit e06c186
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Showing 2 changed files with 11 additions and 7 deletions.
diff --git a/include/sancus_support/sancus_step.h b/include/sancus_support/sancus_step.h
@@ -48,17 +48,17 @@ void timerA_isr_entry2(void)                                                   \
         "sub &%5, &%2\n\t"                                                     \
         /* __ss_isr_interrupted_sm = false */                                  \
         "mov #0x0, &%1\n\t"                                                    \
-        /* check whether r1 register is set (0 if module got interrupted?) */  \
+        /* check whether r1 register is set (0 if module got interrupted) */   \
         "cmp #0x0, r1\n\t"                                                     \
-        /* if module was not interrupted, jump to label "1" */                 \
+        /* if module was not interrupted, jump to label "1" (call end fn) */   \
         "jne 1f\n\t"                                                           \
         /* __ss_isr_interrupted_sm = true */                                   \
         "mov #0x1, &%1\n\t"                                                    \
         /* r1 = __isr_sp */                                                    \
         "mov &%3, r1\n\t"                                                      \
-        /*  */                                                                 \
+        /* push r15 to stack */                                                \
         "push r15\n\t"                                                         \
-        /*  */                                                                 \
+        /* push 0 to stack */                                                  \
         "push #0x0\n\t"                                                        \
         /* check whether __ss_dbg_measuring_reti_latency is set */             \
         "cmp #0x0, &%7\n\t"                                                    \
@@ -72,15 +72,15 @@ void timerA_isr_entry2(void)                                                   \
         "2: \n\t"                                                              \
         /* call the first function parameter */                                \
         "call #" #fct_single_step "\n\t"                                       \
-        /*  */                                                                 \
+        /* push r15 to stack */                                                \
         "push r15\n\t"                                                         \
         /* r15 = __ss_isr_reti_latency */                                      \
         "mov &%6, r15\n\t"                                                     \
         /* r15 += 6 */                                                         \
         "add #0x6, r15 ;\n\t"                                                  \
         /* TACCR0 = r15 */                                                     \
         "mov r15, &%5\n\t"                                                     \
-        /*  */                                                                 \
+        /* pop the stack top to r15 */                                         \
         "pop r15\n\t"                                                          \
         /* TACCTL0 = TACCTL_ENABLE_CONT */                                     \
         "mov %11, &%12\n\t"                                                    \

diff --git a/src/sancus-step/sancus_step.c b/src/sancus-step/sancus_step.c
@@ -17,6 +17,7 @@ int __ss_get_latency(void)
 
 int __ss_dbg_entry_delay = 0;
 int __ss_dbg_measuring_reti_latency = 0;
+int __ss_dbg_init_done = 0;
 int __ss_isr_reti_latency = 0;
 int __ss_sm_exit_latency = 0;
 int __ss_isr_interrupted_sm = 0;
@@ -28,7 +29,9 @@ int __ss_isr_interrupted_sm = 0;
  */
 void __ss_start(void)
 {
-    __ss_init();
+    if (__ss_dbg_init_done == 0) {
+        __ss_init();
+    }
     __asm__("dint\n\t"); // disable interrupts
     timer_irqc(INIT_LATENCY);
 }
@@ -66,6 +69,7 @@ void __ss_init(void)
     printf("entry delay: %d\n", __ss_dbg_entry_delay);
 
     __ss_dbg_measuring_reti_latency = 0;
+    __ss_dbg_init_done = 1;
 }
 
 void __ss_end(void)