CSE 320
Assignment Overview
Summer 2019
Computer Project #6
This assignment develops familiarity with the instruction set architecture of the ARM microprocessor, as well as the format of its machine language instructions.
It is worth 40 points (4% of course grade) and must be completed no later than 11:59 PM on Friday, 6/7.
Assignment Deliverables
The deliverables for this assignment are the following files:
proj06.makefile –themakefilewhichproduces”proj06″ proj06.support.c – the source code for your support module proj06.driver.c –thesourcecodeforyourdrivermodule
Be sure to use the specified file names and to submit them for grading via the CSE handin system before the project deadline.
Assignment Specifications
An assembler is a program which converts assembly language source code statements into machine language instructions; a disassembler is a program which converts machine language instructions into assembly language.
1. You will develop a support module which could be used by a disassembler for ARM machine language instructions. The interface to the support module is the following C function:
void decode( unsigned int, char[] );
The first argument is the bit pattern for an ARM machine language instruction.
The second argument is the address of an array where function “decode” will store a null-terminated character string representing the machine language instruction.
Function “decode” will accept a 32-bit unsigned integer value and attempt to disassemble it. If the bit pattern corresponds to an ARM machine language instruction from the set defined below, function “decode” will produce a human-readable representation of the instruction and store it in the array (the second argument). Otherwise, it will produce an appropriate warning and store it in the array.
The support module will consist of function “decode” and any additional helper functions which you choose to implement. The support module will not perform any input or output operations. For example, the functions in the support module will not call function “scanf” or function “printf”.
2. You will develop a driver module to test your implementation of the support module. The driver module will consist of function “main” and any additional helper functions which you choose to implement. All output will be appropriately labeled.
Your driver module may not be written as an interactive program, where the user supplies input in response to prompts. Instead, your test cases will be included in the source code as literal constants.
Assignment Notes
1. Your driver module and your support module must be in separate source code files.
2. Your source code must be translated by “gcc”, which is a C compiler and accepts C source statements.
3. You must supply a “makefile” (named “proj06.makefile”), and that makefile must produce an executable program named “proj06”.
4. Your support module will recognize the ARM data processing instructions, which have the following format:
Bits 31:26
Bit 25
Bits 24:21
Bit 20
Bits 19:16
Bits 15:12
Bits 7:0
Bits 3:0
111000
I bit
opcode
S bit
Rn
Rd
immediate value (when I=1) Rm (when I=0)
All other bits will be 0.
The sixteen operation codes are given in the following table:
Opcode
Mnemonic
Opcode
Mnemonic
0000
and
1000
tst
0001
eor
1001
teq
0010
sub
1010
cmp
0011
rsb
1011
cmn
0100
add
1100
orr
0101
adc
1101
mov
0110
sbc
1110
bic
0111
rsc
1111
mvn
5. Your support module will produce a human-readable representation of a machine language instruction which is in the same format as ARM assembly language instructions. Registers will appear as the character “r”, followed by a decimal number between 0 and 15. Immediate constants will appear as the characters “#0x”, followed by a hexadecimal number. For example:
Instruction
e086a007
e096a007
e286a007
e1520003
e1a01003
Human-readable form
add rl0, r6, r7
adds rl0, r6, r7
add rl0, r6, #0x7
cmp r2, r3
mov r1, r3
6. Note that the functions in your support module cannot perform any input or output operations. All communication between the driver module and the support module will be done via the two arguments to function “decode”.