Moxa Technologies user manual EM-1240-LX FAQ

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EM-1240-LX FAQ

FAQ 1 Why can I only use vfork( ),and am unable to use fork( )?

Answer 1 uClinux only supports vfork( ). It does not support fork( ). Note that when using vfork( ), the parent process will hang until the child process calls an exec group API, or exits.

FAQ 2 When using a pthread group API, why cannot I use SIGUSR1 and SIGUSR2?

Answer 2 Since a pthread group API uses SIGUSR1 and SIGUSR2 to do a pthread control suspend, restart exit function, we cannot use the SIGUSR1 and SIGUSR2 signals. You will get the same result if you link the pthread. This means that you cannot use -1pthreadto add an option to the linker.

FAQ 3 What is the correct format for linking to an API?

Answer 3 arm-elf-gcc –W1, -elf2flt

(In this example, the API converts elf format to flat format.)