This package enables compatibility with the ISO C standard - ISO/IEC 9899:1990. This allows the user application to use well known standard C library functions, and in eCos starts a thread to invoke the user function main()
This option chooses whether the simple character classification and conversion functions (e.g. isupper(), isalpha(), toupper(), etc.) from <ctype.h> are available as inline functions. This may improve performance and as the functions are small, may even improve code size.