Difference between revisions of "SPO600 64-bit Assembly Language Lab"
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=== Lab Tasks === | === Lab Tasks === | ||
| − | 1. Build the C | + | 1. Build and run the C versions of the program for x86_64. Use objdump to disassemble and review the [[Machine Language|machine code]] in the binaries - make sure you understand it. Save the binaries for later review. |
| + | |||
| + | 2. Review, build, and run the x86_64 assembler code. Use objdump to disassemble and review the [[Machine Language|machine code]] in the binaries - make sure you understand it. | ||
| + | |||
| + | 4. Build and run the C versions of the program for aarch64 (note: you may need to <code>make clean</code>). | ||
| + | |||
| + | 5. Review, build, and run the aarch64 assembler code. Use objdump to disassemble and review the machine code in the binaries, and make sure you understand it. | ||
| + | |||
| + | 6. Here is a basic loop in x86_64 assembler: | ||
| + | |||
| + | .text | ||
| + | .globl _start | ||
| + | |||
| + | start = 0 /* starting value for the loop index */ | ||
| + | max = 10 /* loop exits when the index hits this number (loop condition is i<max */ | ||
| + | |||
| + | _start: | ||
| + | mov $0,%r15 /* loop index */ | ||
| + | |||
| + | loop: | ||
| + | /* ... do something useful here ... */ | ||
| + | |||
| + | inc %r15 /* increment register 15 */ | ||
| + | cmpq $10,%r15 /* see if we're done */ | ||
| + | jne loop /* loop if we're not */ | ||
| + | |||
| + | movq $0,%rdi /* exit status */ | ||
| + | movq $60,%rax /* syscall sys_exit */ | ||
| + | syscall | ||
| + | |||
| + | Extend this loop so that it prints each digit from 0 to 9 like this: | ||
| + | |||
| + | Loop: 0 | ||
| + | Loop: 1 | ||
| + | Loop: 2 | ||
| + | Loop: 3 | ||
| + | Loop: 4 | ||
| + | Loop: 5 | ||
| + | Loop: 6 | ||
| + | Loop: 7 | ||
| + | Loop: 8 | ||
| + | Loop: 9 | ||
| + | |||
| + | {{Admon/tip|Character conversion|In order to print these values, you will need to convert from an integer to digit character. In ASCII/ISO-9959-1/Unicode UTF-8, the digit characters are in the range 48-57 (0x30-0x39). You will also need to assemble the message that is output on each line - you can do this by writing the digit into the message buffer before writing it, or you can perform a sequence of writes for the various portions of the message.}} | ||
Revision as of 16:32, 23 January 2014
It is still under construction and content may change. Do not rely on this information.
In this lab, you will experiment with assembler on the x86_64 and aarch64 platforms.
Perform this lab on ireland.proximity.on.ca.)
Lab 3
Ireland - Configuration
The host Ireland (ireland.proximity.on.ca) has been set up so that you can use it normally as an x86_64 host, or use an emulation environment to build and run aarch64 binaries.
The directory ~/arm64/spo600/examples<code>, which is also accessible as <code>~/spo600-examples, contains these files:
── hello
├── assembler # 'hello world' example programs
│ ├── aarch64 # aarch64 assembler version
│ │ ├── hello.s
│ │ └── Makefile
│ └── x86_64 # x86_64 assembler versions
│ ├── hello-gas.s # 64-bit instructions for assembley with the gnu assembler (called 'gas', /usr/bin/as)
│ ├── hello-nasm.s # 32-bit instructions for assembley with the nasm assembler (/usr/bin/nasm)
│ └── Makefile
└── c
├── hello2.c # C version using the write() syscall wrapper
├── hello.c # C version using printf()
└── Makefile
Throughout this lab, take advantage of make whenever possible.
Lab Tasks
1. Build and run the C versions of the program for x86_64. Use objdump to disassemble and review the machine code in the binaries - make sure you understand it. Save the binaries for later review.
2. Review, build, and run the x86_64 assembler code. Use objdump to disassemble and review the machine code in the binaries - make sure you understand it.
4. Build and run the C versions of the program for aarch64 (note: you may need to make clean).
5. Review, build, and run the aarch64 assembler code. Use objdump to disassemble and review the machine code in the binaries, and make sure you understand it.
6. Here is a basic loop in x86_64 assembler:
.text
.globl _start
start = 0 /* starting value for the loop index */
max = 10 /* loop exits when the index hits this number (loop condition is i<max */
_start:
mov $0,%r15 /* loop index */
loop:
/* ... do something useful here ... */
inc %r15 /* increment register 15 */
cmpq $10,%r15 /* see if we're done */
jne loop /* loop if we're not */
movq $0,%rdi /* exit status */
movq $60,%rax /* syscall sys_exit */
syscall
Extend this loop so that it prints each digit from 0 to 9 like this:
Loop: 0 Loop: 1 Loop: 2 Loop: 3 Loop: 4 Loop: 5 Loop: 6 Loop: 7 Loop: 8 Loop: 9
In order to print these values, you will need to convert from an integer to digit character. In ASCII/ISO-9959-1/Unicode UTF-8, the digit characters are in the range 48-57 (0x30-0x39). You will also need to assemble the message that is output on each line - you can do this by writing the digit into the message buffer before writing it, or you can perform a sequence of writes for the various portions of the message.
