How to print float variable from Trace32 with python command?

Question

I have a simple C code which will update static variable with floating variable. Let's say I have

static float32  totalcount = 60.73f;

I want to know how to get float values from Lauterbach trace32. I have tried to print the float values using below t32api64.dll and ctype method.

error =  ctypes.c_int32(0)
result = ctypes.c_float32(0)

 t32api.T32_Cmd (b"InterCom mycore Var totalcount")
    error = t32api.T32_EvalGet(ctypes.byref(result));
    if (error == 0):
        print("OK");
        print (result.value)
    else:
        print("Nok error")

But I am getting some different ouputt.

Output:

$ python test.py
OK
8.96831017167883e-44

After some research, I understood that t32api.T32_EvalGet() function is not supporting float values. So I would like to know how to print the float values from trace32 using python. Please suggest some method to print float values?

Answer 1

You can either use T32_ExecuteFunction_Double() or T32_EvalGetString():

Example for int T32_ExecuteFunction_Double(const char *pExpression, char *pBuffer, uint32_t BufferSize, double *pResult)

error =  ctypes.c_int32(0)
buffer = (ctypes.c_char * 4096)()
result = ctypes.c_float32(0)
error = t32api.T32_ExecuteFunction(b'Var.FVALUE("totalcount")', buffer, len(buffer), result))
print('Var.FVALUE("totalcount"):, "{result.value}")

Example for int T32_ReadVariableString(const char *symbol, char *string, int maxlen)

error =  ctypes.c_int32(0)
buffer = (ctypes.c_char * 4096)()
error = t32api.T32_Cmd(b"Eval Var.STRing(totalcount)")
error = t32api.T32_EvalGetString(buffer, len(buffer))
if error == 0:
    print(b"Eval Var.STRing(totalcount):", float(buffer.value))

---

Example using the pyrcl package:

import lauterbach.trace32.rcl as t32

with t32.connect() as dbg:
    variable = dbg.variable.read("totalcount")
    print(variable.value)
    # or
    variable = dbg.fnc("Var.FVALUE(totalcount)")
    print(variable)