what is the final output of this?
Database System Concepts
7th Edition
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Chapter1: Introduction
Section: Chapter Questions
Problem 1PE
Related questions
Question
what is the final output of this?
![```assembly
section .data
msg: db 10, "You are at the start.", 10
len: equ $-msg
msg2: db "Done!", 10
len2 equ $-msg2
char: db 0
section .text
global main
print:
mov rax, 1
mov rdi, 1
syscall
ret
main:
xor rax, rax
xor r9, r9
mov r8b, 255
xor r8b, r8b
label1:
cmp r9b, 0
jae label2
mov rsi, msg
mov rdx, len
call print
jmp done
label2:
xor rsi, rsi
mov rsi, 48
add rsi, r9
mov [char], rsi
mov rsi, char
mov rdx, 1
call print
sub r8b, 1
jmp label1
done:
mov rsi, msg2
mov rdx, len2
call print
xor rax, rax
ret
```
### Explanation
This assembly program is written for an x86-64 architecture using the SysV ABI (Application Binary Interface) convention. It consists of two main sections: `.data` and `.text`.
- **.data section**:
- `msg` contains the string "You are at the start.".
- `len` calculates the length of `msg`.
- `msg2` contains the string "Done!".
- `char` is an empty byte used for character manipulation.
- **.text section**:
- Defines the main function and a subroutine for printing strings.
- **Print subroutine**:
- Uses system calls (`syscall`) to print strings to the standard output (file descriptor 1).
- **Main procedure**:
- Initializes registers and sets up loops to print the initial message and decrement a loop counter (`r8b`).
- **label1** and **label2**](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F78de2526-b393-406f-b144-213aa508c7e8%2F5bb7db2f-05f5-4fa1-9901-f38948464373%2F2bjz3f_processed.png&w=3840&q=75)
Transcribed Image Text:```assembly
section .data
msg: db 10, "You are at the start.", 10
len: equ $-msg
msg2: db "Done!", 10
len2 equ $-msg2
char: db 0
section .text
global main
print:
mov rax, 1
mov rdi, 1
syscall
ret
main:
xor rax, rax
xor r9, r9
mov r8b, 255
xor r8b, r8b
label1:
cmp r9b, 0
jae label2
mov rsi, msg
mov rdx, len
call print
jmp done
label2:
xor rsi, rsi
mov rsi, 48
add rsi, r9
mov [char], rsi
mov rsi, char
mov rdx, 1
call print
sub r8b, 1
jmp label1
done:
mov rsi, msg2
mov rdx, len2
call print
xor rax, rax
ret
```
### Explanation
This assembly program is written for an x86-64 architecture using the SysV ABI (Application Binary Interface) convention. It consists of two main sections: `.data` and `.text`.
- **.data section**:
- `msg` contains the string "You are at the start.".
- `len` calculates the length of `msg`.
- `msg2` contains the string "Done!".
- `char` is an empty byte used for character manipulation.
- **.text section**:
- Defines the main function and a subroutine for printing strings.
- **Print subroutine**:
- Uses system calls (`syscall`) to print strings to the standard output (file descriptor 1).
- **Main procedure**:
- Initializes registers and sets up loops to print the initial message and decrement a loop counter (`r8b`).
- **label1** and **label2**
Expert Solution
![](/static/compass_v2/shared-icons/check-mark.png)
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 3 steps
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.Recommended textbooks for you
![Database System Concepts](https://www.bartleby.com/isbn_cover_images/9780078022159/9780078022159_smallCoverImage.jpg)
Database System Concepts
Computer Science
ISBN:
9780078022159
Author:
Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:
McGraw-Hill Education
![Starting Out with Python (4th Edition)](https://www.bartleby.com/isbn_cover_images/9780134444321/9780134444321_smallCoverImage.gif)
Starting Out with Python (4th Edition)
Computer Science
ISBN:
9780134444321
Author:
Tony Gaddis
Publisher:
PEARSON
![Digital Fundamentals (11th Edition)](https://www.bartleby.com/isbn_cover_images/9780132737968/9780132737968_smallCoverImage.gif)
Digital Fundamentals (11th Edition)
Computer Science
ISBN:
9780132737968
Author:
Thomas L. Floyd
Publisher:
PEARSON
![Database System Concepts](https://www.bartleby.com/isbn_cover_images/9780078022159/9780078022159_smallCoverImage.jpg)
Database System Concepts
Computer Science
ISBN:
9780078022159
Author:
Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:
McGraw-Hill Education
![Starting Out with Python (4th Edition)](https://www.bartleby.com/isbn_cover_images/9780134444321/9780134444321_smallCoverImage.gif)
Starting Out with Python (4th Edition)
Computer Science
ISBN:
9780134444321
Author:
Tony Gaddis
Publisher:
PEARSON
![Digital Fundamentals (11th Edition)](https://www.bartleby.com/isbn_cover_images/9780132737968/9780132737968_smallCoverImage.gif)
Digital Fundamentals (11th Edition)
Computer Science
ISBN:
9780132737968
Author:
Thomas L. Floyd
Publisher:
PEARSON
![C How to Program (8th Edition)](https://www.bartleby.com/isbn_cover_images/9780133976892/9780133976892_smallCoverImage.gif)
C How to Program (8th Edition)
Computer Science
ISBN:
9780133976892
Author:
Paul J. Deitel, Harvey Deitel
Publisher:
PEARSON
![Database Systems: Design, Implementation, & Manag…](https://www.bartleby.com/isbn_cover_images/9781337627900/9781337627900_smallCoverImage.gif)
Database Systems: Design, Implementation, & Manag…
Computer Science
ISBN:
9781337627900
Author:
Carlos Coronel, Steven Morris
Publisher:
Cengage Learning
![Programmable Logic Controllers](https://www.bartleby.com/isbn_cover_images/9780073373843/9780073373843_smallCoverImage.gif)
Programmable Logic Controllers
Computer Science
ISBN:
9780073373843
Author:
Frank D. Petruzella
Publisher:
McGraw-Hill Education