From d72d02ca47e68aa08c33c2fcf5dd251fb1dc296e Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Sat, 25 Feb 2023 16:03:27 +1100
Subject: [PATCH] AP_HAL_ChibiOS: remove convenience debug code based on new
 define

bootloaders (at least the ones that need to fit into 16kB pages) don't really have the space for this sort of debug.

I figure if you're debugging a bootloader fault you probably have the know-how to get his information yourself based on the code now being excluded, or add it back in.
---
 .../AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py    | 10 ++++++++++
 libraries/AP_HAL_ChibiOS/system.cpp                  | 12 ++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
index cb74236757f..ffabcaf5508 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
@@ -3038,6 +3038,11 @@ def add_bootloader_defaults(f):
 #ifndef HAL_GCS_ENABLED
 #define HAL_GCS_ENABLED 0
 #endif
+
+// make diagnosing Faults (e.g. HardFault) harder, but save bytes:
+#ifndef AP_FAULTHANDLER_DEBUG_VARIABLES_ENABLED
+#define AP_FAULTHANDLER_DEBUG_VARIABLES_ENABLED 0
+#endif
 ''')
 
 def add_iomcu_firmware_defaults(f):
@@ -3065,6 +3070,11 @@ def add_iomcu_firmware_defaults(f):
 #ifndef AP_VIDEOTX_ENABLED
 #define AP_VIDEOTX_ENABLED 0
 #endif
+
+// make diagnosing Faults (e.g. HardFault) harder, but save bytes:
+#ifndef AP_FAULTHANDLER_DEBUG_VARIABLES_ENABLED
+#define AP_FAULTHANDLER_DEBUG_VARIABLES_ENABLED 0
+#endif
 ''')
 
 def add_normal_firmware_defaults(f):
diff --git a/libraries/AP_HAL_ChibiOS/system.cpp b/libraries/AP_HAL_ChibiOS/system.cpp
index e14b0400e12..34fcedbfd9d 100644
--- a/libraries/AP_HAL_ChibiOS/system.cpp
+++ b/libraries/AP_HAL_ChibiOS/system.cpp
@@ -47,6 +47,12 @@ static_assert(HAL_EXPECTED_SYSCLOCK == STM32_HCLK, "unexpected STM32_HCLK value"
 #endif
 #endif
 
+// debug variables chew up flash, but are handy if you've got a Fault and need
+// easy access to the fault data iun the debugger:
+#ifndef AP_FAULTHANDLER_DEBUG_VARIABLES_ENABLED
+#define AP_FAULTHANDLER_DEBUG_VARIABLES_ENABLED 1
+#endif
+
 extern const AP_HAL::HAL& hal;
 extern "C"
 {
@@ -67,6 +73,7 @@ void HardFault_Handler(void) {
     //For HardFault/BusFault this is the address that was accessed causing the error
     uint32_t faultAddress = SCB->BFAR;
     (void)faultAddress;
+#if AP_FAULTHANDLER_DEBUG_VARIABLES_ENABLED
     bool forced = SCB->HFSR & SCB_HFSR_FORCED_Msk;
     (void)forced;
     uint32_t cfsr = SCB->CFSR;
@@ -83,6 +90,7 @@ void HardFault_Handler(void) {
     (void)isFaultOnUnstacking;
     (void)isFaultOnStacking;
     (void)isFaultAddressValid;
+#endif  // #if AP_FAULTHANDLER_DEBUG_VARIABLES_ENABLED
 
     save_fault_watchdog(__LINE__, faultType, faultAddress, (uint32_t)ctx.lr_thd);
 
@@ -132,6 +140,7 @@ void UsageFault_Handler(void) {
     FaultType faultType = (FaultType)__get_IPSR();
     (void)faultType;
     uint32_t faultAddress = SCB->BFAR;
+#if AP_FAULTHANDLER_DEBUG_VARIABLES_ENABLED
     //Flags about hardfault / busfault
     //See http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0552a/Cihdjcfc.html for reference
     bool isUndefinedInstructionFault = ((SCB->CFSR >> SCB_CFSR_USGFAULTSR_Pos) & (1 << 0) ? true : false);
@@ -146,6 +155,7 @@ void UsageFault_Handler(void) {
     (void)isNoCoprocessorFault;
     (void)isUnalignedAccessFault;
     (void)isDivideByZeroFault;
+#endif  // AP_FAULTHANDLER_DEBUG_VARIABLES_ENABLED
 
     save_fault_watchdog(__LINE__, faultType, faultAddress, (uint32_t)ctx.lr_thd);
 
@@ -165,6 +175,7 @@ void MemManage_Handler(void) {
     (void)faultType;
     //For HardFault/BusFault this is the address that was accessed causing the error
     uint32_t faultAddress = SCB->MMFAR;
+#if AP_FAULTHANDLER_DEBUG_VARIABLES_ENABLED
     (void)faultAddress;
     //Flags about hardfault / busfault
     //See http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0552a/Cihdjcfc.html for reference
@@ -178,6 +189,7 @@ void MemManage_Handler(void) {
     (void)isExceptionUnstackingFault;
     (void)isExceptionStackingFault;
     (void)isFaultAddressValid;
+#endif  // AP_FAULTHANDLER_DEBUG_VARIABLES_ENABLED
 
     save_fault_watchdog(__LINE__, faultType, faultAddress, (uint32_t)ctx.lr_thd);