Remove some debug stuff and fix secure fault triggers

Author: will-v-pi

trustzone/hello_trustzone/nonsecure.c

@@ -11,12 +11,7 @@ bool repeating_timer_callback(__unused struct repeating_timer *t) {
 }
 
 int main() {
-    // Check no user IRQs are available
-    int irq = user_irq_claim_unused(false);
-    if (irq != -1) {
-        goto done;
-    }
-    // Request user IRQs from secure, which stdio_usb will use
+    // Request user IRQ from secure, which stdio_usb will use
     user_irq_request_unused_from_secure(1);
 
     stdio_usb_init();
@@ -25,19 +20,15 @@ int main() {
     struct repeating_timer timer;
     add_repeating_timer_ms(1000, repeating_timer_callback, NULL, &timer);
 
-    printf("My clock speed is %dHz\n", clock_get_hz(clk_sys));
-
     for (int i=0; i < 10; i++) {
         printf("Hello, world, from non-secure!\n");
         rom_secure_call(1, 2, 3, i, SECURE_CALL_PRINT_VALUES);
         sleep_ms(1000);
     }
 
-done:
+    // Demonstrate triggering a secure fault, by reading secure memory at start of SRAM
     printf("Triggering secure fault by reading secure memory\n");
-    // Secure memory is the rest of SRAM after the heap limit
-    extern uint32_t __HeapLimit;
-    volatile uint32_t thing = *(uint32_t*)__HeapLimit;
+    volatile uint32_t thing = *(uint32_t*)SRAM_BASE;
     printf("Some secure memory is %08x\n", thing);
 
     return 0;

trustzone/wifi_tls_verify/nonsecure.c

@@ -147,11 +147,10 @@ int main() {
         printf("Test failed\n");
     }
 
-    done:
+done:
     printf("Triggering secure fault by reading secure memory\n");
-    // Secure memory is the rest of SRAM after the heap limit
-    extern uint32_t __HeapLimit;
-    volatile uint32_t thing = *(uint32_t*)__HeapLimit;
+    // Secure memory is the start of SRAM
+    volatile uint32_t thing = *(uint32_t*)SRAM_BASE;
     printf("Some secure memory is %08x\n", thing);
 
     return 0;