esp32: Adds functionality for application tracing over JTAG

- Implements application tracing module which allows to send arbitrary
   data to host over JTAG. This feature is useful for analyzing
   program modules behavior, dumping run-time application data etc.
 - Implements printf-like logging functions on top of apptrace module.
   This feature is a kind of semihosted printf functionality with lower
   overhead and impact on system behaviour as compared to standard printf.

tools/esp_app_trace/logtrace_proc.py

@@ -0,0 +1,163 @@
+#!/usr/bin/env python
+#
+
+import argparse
+import struct
+import sys
+import pylibelf as elf
+import pylibelf.util as elfutil
+import pylibelf.iterators as elfiter
+import pylibelf.constants as elfconst
+from ctypes import *
+
+class ESPLogTraceParserError(RuntimeError):
+    def __init__(self, message):
+        RuntimeError.__init__(self, message)
+
+
+class ESPLogTraceRecord(object):
+    def __init__(self, fmt_addr, log_args):
+        super(ESPLogTraceRecord, self).__init__()
+        self.fmt_addr = fmt_addr
+        self.args = log_args
+
+    def __repr__(self):
+        return "fmt_addr = 0x%x, args = %d/%s" % (self.fmt_addr, len(self.args), self.args)
+
+
+def logtrace_parse(fname):
+    ESP32_LOGTRACE_HDR_FMT = '<BL'
+    ESP32_LOGTRACE_HDR_SZ = struct.calcsize(ESP32_LOGTRACE_HDR_FMT)
+
+    recs = []
+    try:
+        ftrc = open(fname, 'rb')
+    except OSError as e:
+        raise ESPLogTraceParserError("Failed to open trace file (%s)!" % e)
+    # data_ok = True
+    while True:
+        # read args num and format str addr
+        try:
+            trc_buf = ftrc.read(ESP32_LOGTRACE_HDR_SZ)
+        except IOError as e:
+            raise ESPLogTraceParserError("Failed to read log record header (%s)!" % e)
+        if len(trc_buf) < ESP32_LOGTRACE_HDR_SZ:
+            # print "EOF"
+            if len(trc_buf) > 0:
+                print "Unprocessed %d bytes of log record header!" % len(trc_buf)
+                # data_ok = False
+            break
+        try:
+            nargs,fmt_addr = struct.unpack(ESP32_LOGTRACE_HDR_FMT, trc_buf)
+        except struct.error as e:
+            raise ESPLogTraceParserError("Failed to unpack log record header (%s)!" % e)
+        # read args
+        args_sz = struct.calcsize('<%sL' % nargs)
+        try:
+            trc_buf = ftrc.read(args_sz)
+        except IOError as e:
+            raise ESPLogTraceParserError("Failed to read log record args (%s)!" % e)
+        if len(trc_buf) < args_sz:
+            # print "EOF"
+            if len(trc_buf) > 0:
+                print "Unprocessed %d bytes of log record args!" % len(trc_buf)
+                # data_ok = False
+            break
+        try:
+            log_args = struct.unpack('<%sL' % nargs, trc_buf)
+        except struct.error as e:
+            raise ESPLogTraceParserError("Failed to unpack log record args (%s)!" % e)
+        # print log_args
+        recs.append(ESPLogTraceRecord(fmt_addr, list(log_args)))    
+
+    ftrc.close()
+    # sorted(recs, key=lambda rec: rec.fmt_addr)
+    return recs
+
+
+def logtrace_get_str_from_elf(felf, str_addr):
+    tgt_str = ""
+    for sect in elfiter.sections(felf):
+        hdr = elfutil.section_hdr(felf, sect)
+        if hdr.sh_addr == 0 or hdr.sh_type != elfconst.SHT_PROGBITS:
+            continue
+        if str_addr < hdr.sh_addr or str_addr >= hdr.sh_addr + hdr.sh_size:
+            continue
+        # print "Found SECT: %x..%x @ %x" % (hdr.sh_addr, hdr.sh_addr + hdr.sh_size, str_addr - hdr.sh_addr)
+        sec_data = elfiter.getOnlyData(sect).contents
+        buf = cast(sec_data.d_buf, POINTER(c_char))
+        for i in range(str_addr - hdr.sh_addr, hdr.sh_size):
+            if buf[i] == "\0":
+                break
+            tgt_str += buf[i]
+        if len(tgt_str) > 0:
+            return tgt_str
+    return None
+
+def logtrace_formated_print(recs, elfname, no_err):
+    try:
+        felf = elfutil.open_elf(elfname)
+    except OSError as e:
+        raise ESPLogTraceParserError("Failed to open ELF file (%s)!" % e)
+
+    for lrec in recs:
+        fmt_str = logtrace_get_str_from_elf(felf, lrec.fmt_addr)
+        i = 0
+        prcnt_idx = 0
+        while i < len(lrec.args):
+            prcnt_idx = fmt_str.find('%', prcnt_idx, -2) # TODO: check str ending with %
+            if prcnt_idx == -1:
+                break
+            prcnt_idx += 1 #  goto next char
+            if fmt_str[prcnt_idx] == 's':
+                # find string
+                arg_str = logtrace_get_str_from_elf(felf, lrec.args[i])
+                if arg_str:
+                    lrec.args[i] = arg_str
+            i += 1
+        # print "\nFmt = {%s}, args = %d/%s" % lrec
+        fmt_str = fmt_str.replace('%p', '%x')
+        # print "=====> " + fmt_str % lrec.args
+        try:
+            print fmt_str % tuple(lrec.args),
+            # print ".",
+            pass
+        except Exception as e:
+            if not no_err:
+                print "Print error (%s)" % e
+                print "\nFmt = {%s}, args = %d/%s" % (fmt_str, len(lrec.args), lrec.args)
+
+    elf.elf_end(felf)
+
+def main():
+
+    parser = argparse.ArgumentParser(description='ESP32 Log Trace Parsing Tool')
+
+    parser.add_argument('trace_file', help='Path to log trace file', type=str)
+    parser.add_argument('elf_file', help='Path to program ELF file', type=str)
+    # parser.add_argument('--print-details', '-d', help='Print detailed stats', action='store_true')
+    parser.add_argument('--no-errors', '-n', help='Do not print errors', action='store_true')
+    args = parser.parse_args()
+
+    # parse trace file
+    try:
+        print "Parse trace file '%s'..." % args.trace_file
+        lrecs = logtrace_parse(args.trace_file);
+        print "Parsing completed."
+    except ESPLogTraceParserError as e:
+        print "Failed to parse log trace (%s)!" % e
+        sys.exit(2)
+    # print recs
+    # get format strings and print info
+    print "===================================================================="
+    try:
+        logtrace_formated_print(lrecs, args.elf_file, args.no_errors);
+    except ESPLogTraceParserError as e:
+        print "Failed to print log trace (%s)!" % e
+        sys.exit(2)
+    print "\n====================================================================\n"
+
+    print "Log records count: %d" % len(lrecs)
+
+if __name__ == '__main__':
+    main()