Write six (6) ARM assembly language subroutines, called output_character, read_character, read_string,
output_string, uart_init, and substring_test. These subroutines will allow a user to use HyperTerminal to
enter data and the ARM processor to display data in HyperTerminal via the UART. All user-input should be
echoed back to the display. Your program will prompt the user to enter two strings, implement a simple test
to determine if the second string resides within the first, and then report the position of the second string in
the first (or a message indicating the second string does not reside in the first if that is the case). For example,
if the first string entered is microprocessor and the second is processor, the user should be told that processor
is located in position 5 of microprocessor. Similarly if the first string entered is reference_manual and the
second sting is book, the user should be informed that the book is not found in reference_manual. Note that
the user-entered strings are terminated by hitting Enter and the first position in the string is considered to be
position zero (0).

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