Page 127 - DCAP507_SYSTEM_SOFTWARE

Unit 8: Introduction to Linking and Loading

for a while, the loader brings the necessary subroutine in the main memory and then the Notes
execution process is resumed. Thus dynamic linking both the loading and linking is performed
dynamically.

Self Assessment

Fill in the blanks:
10. The program which performs allocation, relocation and linking is called ............................
11. The binder which performs the linking function and generates adequate information
concerning allocation and relocation and writes this information along with the program
code in the file is known as ............................
12. The output of translator is a program known as ............................

13. The program which is accountable for booting up the system is known as ............................
14. The ............................ structure comprises multiple root/nodes and edges.
15. In ............................ linking, the binder first makes a load module in which along with
program code the allocation and relocation information is accumulated.

8.3 Summary

 Loader is defined as a utility program which considers object code as input organizes it for
implementation and loads the executable code into the memory.
 In "Compile and go" loader, the instruction is read line by line, its machine code is
attained and it is directly placed in the major memory at some recognized address.

 In General Loader Scheme loader scheme, the source program is transformed to object
program by some translator (assembler).
 Absolute loader is a type of loader in which relocated object files are produced, loader
accepts these files and positions them at particular locations in the memory.
 The general process of establishing the relations among the subroutines can be theoretically
known as a_ subroutine linkage.
 Relocation is the procedure of modernizing the addresses used in the address sensitive
instructions of a program.

 The absolute address can be directly utilized to map the object code in the main memory.
 The relative address is only after the addition of relocation constant to the object code
address.

 The direct linking loader is the main common type of loader which is a relocatable loader.
 In dynamic linking, the binder first makes a load module in which along with program
code the allocation and relocation information is accumulated.

8.4 Keywords

Absolute Address: The absolute address can be directly utilized to map the object code in the
main memory.
Absolute Loader: Absolute loader is a type of loader in which relocated object files are produced,
loader accepts these files and positions them at particular locations in the memory.

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