Summary

1And in Conclusion $\dots$ ¶

We spent one chapter covering one figure:

"Vertical flowchart of the translation and load pipeline: C source foo.c is compiled to assembly foo.s, assembled to object file foo.o, linked with lib.o to produce executable a.out, then loaded into memory. Each stage appears as a color-coded box with arrows showing inputs and outputs between files and the Compiler, Assembler, Linker, and Loader." — Flow chart for steps for compiling and running a C program.

The Compiler converts a single high-level language file into a single assembly language file.
The Assembler removes pseudoinstructions, converts what it can to machine language, creates checklist for the linker (relocation table).
- These details are stored in an object file.
- The assembler does 2 passes to resolve addresses in the text segment, handling internal references to position-independent code.
The Linker combines several .o files and resolves absolute addresses.
- The linker enables separate compilation, libraries that need not be compiled, and resolves remaining addresses (more details)
The Loader loads executable into memory and begins execution.

2Textbook Readings¶

P&H 2.12

3Exercises¶

Check your knowledge!

3.1Conceptual Review¶

Solution to Exercise 1 #

Two: The first finds all the label addresses, and the second resolves forward references while using these label addresses.

Solution to Exercise 2 #

The assembler usually handles relative addressing. The linker handles absolute addressing, resolving the references to memory locations outside.

Solution to Exercise 3 #

Header: Sizes and positions of the other parts
Text: The machine code
Data: Binary representation of any data in the source file
Relocation Table: Identifies lines of code that need to be “handled” by the Linker (jumps to external labels (e.g. lib files), references to static data)
Symbol Table: List of file labels and data that can be referenced across files
Debugging Information: Additional information for debuggers