Description
1 Overview
Each student is asked to convert a number of C-subroutines into VisUAL compatible ARM Assembly Language.
1.1 Objectives
Understanding Assembly language code
Explore the dierence between higher-leVel language and Assembly
2 Detailed Description
2.1 Introduction
The ARM architecture has quickly become the go-to platform for mobile and embedded systems. ARM
supports a software toolchain built around the Uni ed Assembler Language (UAL). In this project you will
use a subset of the ARM assembly code that is compatible with the VisUAL ARM emulator system. Your
task is to write Assembly language programs which correspond to provided C programs. In Blackboard, you
will nd three sets of C code, along with the corresponding header les and a make le for each one. The C
code descriptions are included below.
2.2 What to do
You are provided with three applications written in C. The three programs are described in the subsections
below. You need to use the subset of Assembly Language instructions available in the VisUAL emulator to
re-implement these programs.
2.2.1 change.c
Computes the number of dollars, quarters, nickels, dimes, and pennies are required to provide correct change:
1
The amount of change is set in main. A series of computations are performed to determine the number of
dollars, quarters, dimes, nickels, and pennies.
Your assembly language version should start with the amount of change in R3, with dollars, quarters, dimes,
nickels, and pennies stored in 4 byte values in: FP-4, FP-8, FP-12, FP-16, and FP-20; respectively.
2.2.2 concat.c
Concatenates 2 strings. The key things is the subroutine allocate(), that allocates memory from the heap.
You should create this is an independent function, and call that function from your main routine.
The amount of change is set in main. A series of computations are performed to determine the number of
dollars, quarters, dimes, nickels, and pennies.
Your assembly language version should start with two strings in R3 and R1 with their lengths in R2 and R0,
respectively. You should allocate enough room from both strings and the subsequent null from the heap.
Your should then copy each string into the newly allocated memory and return the address in R0.
2.2.3 hamming.c
Uses hamming code parity to correct errors in a 16-bit value.
The input value for correction should be assumed to be in R3, and the corrected 16-bit value should be
output to R0. The algorithm itself looks a bit complex but isn’t really that tough to code. The issue will
likely be translating for-loops into assembly language.
2.3 Running your code
Please use the VisUAL ARM emulator to test your code. You can download VisUAL at: https://
salmanarif.bitbucket.io/visual/downloads.html
3 Submission
Each of your source code les must have a comment near the top that contains your name, StudentID, and
M-number.
The project should be submitted via Blackboard by October 25, 2021, 11:59pm. Follow these instructions
to turn in your project.
You should submit the following les:
change.s
concat.s
hamming.s
2
any other source les your project needs
The following submission directions use the instructions that we will use for all projects this semester.
1. create a directory for your project:
mkdir c2asm 1
2. create (or copy) all of your source les in this directory. Example: To copy a le called example.s into
your c2asm directory:
cp example.s c2asm 1
3. change parent directory of your project directory:
cd c2asm/.. 1
4. Create a tar le named
tar -czf
2
5. Finally, submit the compressed tar le to Blackboard in accordance with the class policies.
Late assignments will not be given credit.
4 Grading
While this rubric is subject to change based on class performance, the current grading rubric for this assignment is as follows:
component value
Correctness 40
Completeness 40
Code Quality 20
3
