What steps will reproduce the problem? Cross compile with arm-xilinx-linux-gnueabi-gcc (Sourcery CodeBench Lite 2012.09-104) 4.7.2 .

What is the expected output? What do you see instead? Any command line switch results in usage report (usage_long()), even if every command line switch given is as documented, e.g., iperf -s .

What version of the product are you using? On what operating system? Version 3.0b5 over Linux (kernel 3.8) compiled for arm-xilinx-linux-gnueabi cross toolchain (as reported above).

Problem analysis and solution: The problem is a result of wrong data type given to the local variable "ch" in iperf_api.c::iperf_parse_arguments(). The original data type for "ch" is "char". When ch is assigned with return code of getopt_long() it actually assigns/casts int into char. The result is that when the end of arguments list is reached, getopt_long() returns (-1), but it is casted to (unsigned) char and becomes 0xFF before compared to the (-1) of the "while" statement (iperf_api.c line 437). I suspect that this is not seen on other platforms because "char" may default to "signed char" is some platform but to "unsigned char" in others (there is no standard for that default...). Anyway, since getopt_long() returns int, ch should be int, too.

This issue may be related to issue #49. Still I think that ch should be int, because that's the return code of getopt_long().

I agree with your diagnosis.