ARM EN0-001 Online Practice Questions and Exam Preparation

ARM EN0-001 Online Questions & Answers

• Question 1:

  Which of the following functions can be performed by a spinlock?

  A. Encrypting sensitive data on a network
  B. Preventing interrupts from being received by a CPU
  C. Preventing unauthorized access to an ARM powered device
  D. Protecting a critical section or data structure from concurrent access
  D. Protecting a critical section or data structure from concurrent access

• Question 2:

  Which of these C99 keywords can be used to indicate that two arrays do not overlap?

  A. "pure"
  B. "volatile"
  C. "static"
  D. "restrict"
  D. "restrict"

• Question 3:

  When the processor is executing in Thumb state, which of the following statements is correct about the values stored in R15?

  A. Bits[31:16] are duplicated with bits[15:0]
  B. The PC value is stored in bits[31:1] and bit[0] is treated as zero
  C. The PC value is stored in bits[31:16] and bits[15:0] are undefined
  D. The PC value is stored in bits[15:0] and bits[31:16] are undefined
  B. The PC value is stored in bits[31:1] and bit[0] is treated as zero

• Question 4:

  In a system using the Security Extensions, how does the Secure Monitor execute a switch from Secure to Non-secure state?

  A. Encrypts Secure register contents, sets the NS bit in SCTLR and branches directly to Normal world code
  B. Saves Secure register contents, sets all registers to zero, sets the NS bit in SCTLR and branches directly to Normal world code
  C. Saves Secure register contents, loads Non-secure ones from memory, sets the NS bit in SCTLR and performs an exception return
  D. Sets the NS bit in SCTLR and performs an exception return - all registers are banked in hardware and switched automatically
  C. Saves Secure register contents, loads Non-secure ones from memory, sets the NS bit in SCTLR and performs an exception return

• Question 5:

  It is common to declare structures as "packed" in order to minimize data memory size. Which of the following accurately describes the effect of this?

  A. Members will be stored as bit-fields
  B. Data Aborts will be disabled for all structure accesses
  C. Structure members will be re-ordered so that the smallest are first
  D. Multi-byte members are not required to be naturally aligned
  D. Multi-byte members are not required to be naturally aligned

• Question 6:

  A function written in C has the prototype:

  void my_function(float a. double b, float c);

  The function is built and linked into an application using hard floating-point linkage. What registers are used to pass arguments to the function?

  A. a->s0; b->d0; c->s1
  B. a->s0; b->d1; c->s1
  C. a->d0; b->d1; c->d2
  D. a->s0; b->d1; c-> s2
  B. a->s0; b->d1; c->s1

• Question 7:

  Which of these items is typically shared between threads running in the same Operating System (OS) process?

  A. Stack
  B. Memory map
  C. Register values
  D. Program Counter
  B. Memory map

• Question 8:

  When using a Generic Interrupt Controller (GIC), how does code cause a software-generated interrupt?

  A. By executing an SGI instruction
  B. By writing to a register in the GIC
  C. By writing to the F bit in the CPSR
  D. By writing to the I bit in the CPSR
  B. By writing to a register in the GIC

• Question 9:

  Consider the following instruction sequence:

  STR r0, [r2] ; instruction A

  DSB ADD r0, r1, r2 ; instruction B LDR r3, [r4] ; instruction C SUB r5, r6, #3 ; instruction D At what point will execution pause until the STR access is complete?

  A. After instruction A and before the DSB
  B. After the DSB and before instruction B
  C. After instruction B and before instruction C
  D. After instruction C and before instruction D
  B. After the DSB and before instruction B

• Question 10:

  In an ARMv7-A processor, which control register is used to enable the Memory Management Unit (MMU)?

  A. The ACTLR
  B. The SCTLR
  C. The TTBCR
  D. The CONTEXTIDR
  B. The SCTLR