arm: move trace dump to crash handler

arm/crash.cc

@@ -3,6 +3,7 @@
 #include "gpio.h"
 #include "itoa.h"
 #include "sleep.h"
+#include "trace.h"
 #include "uart.h"
 
 extern "C" uint32_t _initial_stack_pointer, _text_begin, _text_end;
@@ -80,6 +81,8 @@ void CrashHandler(Armv6mRegs* regs) {
     UartWriteCrash("- Stack trace:\r\n");
     StackTrace(reinterpret_cast<uint32_t*>(regs->sp));
 
+    tracing::dump();
+
     while (1) {
         gpio0->data = 0x55;
         sleep(100);

arm/main.cc

@@ -18,10 +18,7 @@ void Uart0Isr() {
     HandleUartIsr();
 }
 
-void Timer0Isr() {
-    tracing::dump();
-    __builtin_trap();
-}
+void Timer0Isr() { __builtin_trap(); }
 
 void SetupUart() {
     InitUarts();

arm/stdlib.cc

@@ -7,14 +7,19 @@
 #include "timer.h"
 #include "uart.h"
 
+#ifndef SBRK_STATS
+#define SBRK_STATS 0
+#endif
+
 extern unsigned char _heap_begin, _heap_end;
 
 namespace {
+[[maybe_unused]]
 void LogStats(unsigned char* heap) {
     char number[] = "00000000\r\n";
-    UartWriteBlocking("Program break now at 0x");
+    UartWriteCrash("Program break now at 0x");
     itoa(reinterpret_cast<int>(heap), number);
-    UartWriteBlocking(number);
+    UartWriteCrash(number);
 }
 }  // namespace
 
@@ -22,11 +27,13 @@ extern "C" void* _sbrk(int increment) {
     static unsigned char* heap = &_heap_begin;
     unsigned char* prev_heap = heap;
     if (heap + increment >= &_heap_end) {
-        UartWriteBlocking("Heap overflow!\r\n");
+        UartWriteCrash("Heap overflow!\r\n");
         return reinterpret_cast<void*>(-1);
     }
     heap += increment;
+#if SBRK_STATS
     LogStats(heap);
+#endif
     return prev_heap;
 }