Implement custom abort and fault handler for debugging

src/runtime/runtime_cortexm.go

@@ -3,7 +3,6 @@
 package runtime
 
 import (
-	"device/arm"
 	"unsafe"
 )
 
@@ -40,16 +39,6 @@ func preinit() {
 	}
 }
 
-func abort() {
-	// disable all interrupts
-	arm.DisableInterrupts()
-
-	// lock up forever
-	for {
-		arm.Asm("wfi")
-	}
-}
-
 // The stack layout at the moment an interrupt occurs.
 // Registers can be accessed if the stack pointer is cast to a pointer to this
 // struct.
@@ -63,35 +52,3 @@ type interruptStack struct {
 	PC  uintptr
 	PSR uintptr
 }
-
-// This function is called at HardFault.
-// Before this function is called, the stack pointer is reset to the initial
-// stack pointer (loaded from addres 0x0) and the previous stack pointer is
-// passed as an argument to this function. This allows for easy inspection of
-// the stack the moment a HardFault occurs, but it means that the stack will be
-// corrupted by this function and thus this handler must not attempt to recover.
-//
-// For details, see:
-// https://community.arm.com/developer/ip-products/system/f/embedded-forum/3257/debugging-a-cortex-m0-hard-fault
-// https://blog.feabhas.com/2013/02/developing-a-generic-hard-fault-handler-for-arm-cortex-m3cortex-m4/
-//export handleHardFault
-func handleHardFault(sp *interruptStack) {
-	print("fatal error: ")
-	if uintptr(unsafe.Pointer(sp)) < 0x20000000 {
-		print("stack overflow")
-	} else {
-		// TODO: try to find the cause of the hard fault. Especially on
-		// Cortex-M3 and higher it is possible to find more detailed information
-		// in special status registers.
-		print("HardFault")
-	}
-	print(" with sp=", sp)
-	if uintptr(unsafe.Pointer(&sp.PC)) >= 0x20000000 {
-		// Only print the PC if it points into memory.
-		// It may not point into memory during a stack overflow, so check that
-		// first before accessing the stack.
-		print(" pc=", sp.PC)
-	}
-	println()
-	abort()
-}