From 0eb2470a61da7397525ff23a2e9419ddec6c211e Mon Sep 17 00:00:00 2001
From: rusefi <rusefillc@gmail.com>
Date: Tue, 12 Feb 2019 18:47:16 -0500
Subject: [PATCH] getMaxUsedStack() - stack usage reseach mini progress

---
 firmware/global.h         |  1 +
 firmware/util/efilib2.cpp | 13 +++++++++++++
 firmware/util/efilib2.h   |  4 ++++
 3 files changed, 18 insertions(+)

diff --git a/firmware/global.h b/firmware/global.h
index 304847f4f3..82d3adfbde 100644
--- a/firmware/global.h
+++ b/firmware/global.h
@@ -101,6 +101,7 @@ typedef unsigned int time_t;
 
 /*
  * Stack debugging
+ * See also getMaxUsedStack()
  */
 int getRemainingStack(thread_t *otp);
 
diff --git a/firmware/util/efilib2.cpp b/firmware/util/efilib2.cpp
index 34335fcffe..5b0a1358d1 100644
--- a/firmware/util/efilib2.cpp
+++ b/firmware/util/efilib2.cpp
@@ -39,3 +39,16 @@ efitime_t Overflow64Counter::update(uint32_t value) {
 	return state.highBits + state.lowBits;
 }
 #endif
+
+int getMaxUsedStack(uint8_t *ptr, int size) {
+	/**
+	 * maximum used stack size total stack buffer size minus position of first modified byte
+	 */
+	int used = 0;
+	for (int i = 0; i < size; i++) {
+		if (ptr[i] != CH_DBG_STACK_FILL_VALUE) {
+			return size - i;
+		}
+	}
+	return 0;
+}
diff --git a/firmware/util/efilib2.h b/firmware/util/efilib2.h
index 69fe8beaed..e311d48e0e 100644
--- a/firmware/util/efilib2.h
+++ b/firmware/util/efilib2.h
@@ -17,6 +17,10 @@ typedef struct {
 } State64;
 
 void updateAndSet(State64 *state, uint32_t value);
+/**
+ * @return for a given stack memory region returns how much stack was ever used
+ */
+int getMaxUsedStack(uint8_t *ptr, int size);
 
 class Overflow64Counter
 {