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You're reading from  Mastering Assembly Programming

Product typeBook
Published inSep 2017
Reading LevelIntermediate
PublisherPackt
ISBN-139781787287488
Edition1st Edition
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Alexey Lyashko
Alexey Lyashko
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Alexey Lyashko

Alexey Lyashko is an Assembly language addict, independent software reverse engineer, and consultant. At the very beginning of his career, when he was a malware researcher at Aladdin Knowledge Systems, he invented and developed a generic code recognition method known as HOFA™. After spending a few years in the anti-malware industry and gaining sufficient experience in low-level development and reverse engineering, Alexey switched to content protection and worked as a reverse engineering consultant with Irdeto's BD+ department, actively participating in content protection technology development. Since 2013, he has worked with several software development companies providing reverse engineering and low-level software development consultancy.
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Data types and their definitions

Before we start working with Assembly instructions, we have to know how to define data, or, to be more precise, how to tell the assembler which type of data we are using.

The Flat Assembler supports six built-in types of data and allows us to either define or declare variables. The difference between a definition and a declaration in this case is that when we define a variable we also assign a certain value to it, but when we declare, we simply reserve space for a certain type of data:

Variable definition format: [label] definition_directive value(s)

  • label: This is optional, but addressing an unnamed variable is harder

Variable declaration format: [label] declaration_directive count

  • label: This is optional, but addressing an unnamed variable is harder
  • count: This tells the assembler how many entries of the type specified in declaration_directive...
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Mastering Assembly Programming
Published in: Sep 2017Publisher: PacktISBN-13: 9781787287488

Author (1)

author image
Alexey Lyashko

Alexey Lyashko is an Assembly language addict, independent software reverse engineer, and consultant. At the very beginning of his career, when he was a malware researcher at Aladdin Knowledge Systems, he invented and developed a generic code recognition method known as HOFA™. After spending a few years in the anti-malware industry and gaining sufficient experience in low-level development and reverse engineering, Alexey switched to content protection and worked as a reverse engineering consultant with Irdeto's BD+ department, actively participating in content protection technology development. Since 2013, he has worked with several software development companies providing reverse engineering and low-level software development consultancy.
Read more about Alexey Lyashko