Consider the following code snippet: #define TIMER_BASE 0x40010000 void configure_timer(){ uint32_t config_reg = (uint32_t)(TIMER_BASE + 0x00); uint8_t status_reg = (uint8_t)(TIMER_BASE + 0x04); uint16_t counter_reg = (uint16_t)(TIMER_BASE + 0x08); config_reg = 0x1; while((status_reg & 0x1) == 0); counter_reg = 0xFFFF; } What are the sizes of the config_reg, status_reg, and counter_reg registers, respectively?

(A) Sizes of all the registers are 4-byte.

(B) Sizes of ‘config_reg‘, ‘status_reg‘, and ‘counter_reg‘ are 4-byte, 1-byte, and 2- byte respectively.

(C) Sizes of ‘config_reg‘, ‘status_reg‘, and ‘counter_reg‘ are 2-byte, 1-byte, and 2- byte respectively.

(D) Sizes of ‘config_reg‘, ‘status_reg‘, and ‘counter_reg‘ are 1-byte, 2-byte, and 4- byte respectively.

What does the following ‘xv6‘ code snippet accomplish? int pid; pid = fork(); if (pid == 0) { execlp("ls", "ls", "-l", NULL); exit(0); } else if (pid > 0) { int status; wait(&status); }

(A) Both the parent and child processes execute the ‘ls‘ command concurrently.

(B) The child process executes the ‘ls -l‘ command, and the parent process waits for it to complete.

(C) The parent process executes the ‘ls -l‘ command, and the child process terminates.

Operating Systems Quiz 1: 23 February 2025 (January 2025 term)

Question 1

+3 marksOne correct option

If the memory map for a device starts from the offset 0x40005000 and has a size of 1024 bytes in a 32-bit addressing scheme, what will be the last address in the memory map?

A
0x400053FF
B
0x40005400
C
0x400052FF
D
0x40004FFF

Question 2

+3 marksOne correct option

Consider the following code snippet:

1#define TIMER_BASE 0x40010000
2
3void configure_timer(){
4    uint32_t *config_reg = (uint32_t*)(TIMER_BASE + 0x00);
5    uint8_t *status_reg = (uint8_t*)(TIMER_BASE + 0x04);
6    uint16_t *counter_reg = (uint16_t*)(TIMER_BASE + 0x08);
7
8    *config_reg = 0x1;
9    while((*status_reg & 0x1) == 0);
10    *counter_reg = 0xFFFF;
11}

What are the sizes of the config_reg, status_reg, and counter_reg registers, respectively?

A
Sizes of all the registers are 4-byte.
B
Sizes of ‘config_reg‘, ‘status_reg‘, and ‘counter_reg‘ are 4-byte, 1-byte, and 2- byte respectively.
C
Sizes of ‘config_reg‘, ‘status_reg‘, and ‘counter_reg‘ are 2-byte, 1-byte, and 2- byte respectively.
D
Sizes of ‘config_reg‘, ‘status_reg‘, and ‘counter_reg‘ are 1-byte, 2-byte, and 4- byte respectively.

Question 3

+3 marksOne correct option

What does the following ‘xv6‘ code snippet accomplish?

1int pid;
2
3pid = fork();
4if (pid == 0) {
5    execlp("ls", "ls", "-l", NULL);
6    exit(0);
7} else if (pid > 0) {
8    int status;
9    wait(&status);
10}

A
Both the parent and child processes execute the ‘ls‘ command concurrently.
B
The child process executes the ‘ls -l‘ command, and the parent process waits for it to complete.
C
The parent process executes the ‘ls -l‘ command, and the child process terminates.
D
None of these

16 more questions in this paper

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More on the Operating Systems Quiz 1 23 Feb 2025 paper

The IIT Madras BS Operating Systems (Operating Systems) Quiz 1 paper sat on 23 Feb 2025, in the January 2025 term: 19 questions for 50 marks in 120 minutes. The first 3 questions are below. Sign in with Google — it is free — to see the whole paper with its answers and explanations, in learning mode or as a timed mock test.

Feature	Operating Systems Quiz 1 23 Feb 2025 at a glance
Term	January 2025 term
Subject	Operating Systems
Course code	BSCS4022
Questions	19
Marks	50
Duration	120 min
MCQ	17
MSQ	2
Official paper	IIT M IMPROVEMENT AN EXAM QIM2 23 Feb 2025
Negative marking	No negative marking.
Updated	25 Sept 2026

Operating Systems Quiz 1: 23 February 2025 (January 2025 term)

Question 1

Question 2

Question 3

16 more questions in this paper

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