1,885
edits
Changes
no edit summary
=== Code Examples ===
The code examples for this lab are available in the file <code>/public/spo600-assembler-lab-examples.tgz</code> on each of the [[SPO600 Servers]].
Unpacking the archive in your home directory will produce the following directory structure:
spo600
Throughout this lab, take advantage of ''[[make and Makefiles|make]]'' whenever possible.
* [[x86_64 Register and Instruction Quick Start]]
* [[aarch64 Register and Instruction Quick Start]]
=== Optional Investigation ===
1. Build and run the three C versions of the program for x86_64 and aarch64. Take a look at the differences in the code.
2. Use the <code>objdump -d</code> command to dump (print) the object code (machine code) and disassemble it into assembler for each of the binaries. Find the <code><nowiki><main></nowiki></code> section and take a look at the code. Also notice the total amount of code.
3. Review, build, and run the x86_64 assembly language programs. Take a look at the code using <code>objdump -d '''objectfile'''</code> and compare it to the source code. Notice the absence of other code (compared to the C binary, which had a lot of extra code).
4. Build and run the assembly language version of the program for aarch64. Verify that you can disassemble the object code in the ELF binary using <code>objdump -d ''objectfile''</code> and take a look at the code.
=== Lab Tasks ===
{{Admon/tip|2-Digit Conversion|You will need to take the loop index and convert it to a 2-digit decimal number by dividing by 10. To do this, use the <code>div</code> instruction, which takes the dividend from rax and the divisor from register supplied as an argument. The quotient will be placed in rax and the remainder will be placed in rdx.}}
5. Repeat Change the previous step for x86_64code as needed to suppress the leading zero (printing 0-30 instead of 00-30).
5. Repeat the previous two steps for x86_64.
=== Deliverables ===
1. Complete the group lab section, above.
2. Extend the assembler programs (both x86_64 and aarch64) to suppress the high digit when it is 0. In other words, the printed values should progress from 0-30 instead of from 00-30. It is OK to output a space in place of the suppressed digit (this will cause the numbers to be aligned vertically in the output).
3. Blog about the programs you've written. Describe the experience of writing and debugging in assembler, as compared to writing in other languages. Contrast x86_64 and aarch64 assembler, your experience with each, and your opinions of each. Include links to the source code for both of your assembler programs.
=== Optional Challenge ===
