1. CALL & Pthread

2. CALL & Pthread
yiming

3. Interpretation vs Translation
Interpreter: Directly executes a program in the source language
For example:
python foo.py
sh foo.sh
Translator: Converts a program from the source language to anequivalent program in another language
gcc -FLAG flags foo.c -o foo
./foo
javac logism.java –o logism.jar
java -jar logism.jar

4. CALL chain
Compiler
Assembler
Linker
Loader

5. High-Level Language Code -> Assembly Language Code (e.g. MAL)
Compiler foo.s
High-Level Language Code -> Assembly Language Code (e.g. MAL)
Convert marcos …
Output may contain pseudo-instructions
For example:
Move $x $y

6. Assembler-Proj1.1 foo.o
Assembly Language Code (MAL) -> Object Code, information tables(TAL)
Totally numbers
TAL is some numbers

7. Assembler-Proj1.1 foo.o Contains 2 passes. first pass Second pass
Replace pseudo-instruction
To code without labels
Second pass
Handle branches and labels

8. Assembler-Proj1.1 pass1 TODO list
Skip comments
Add labels in symbol table (labels, data)
Give addresses
Check if invalid inst
int pass_one(FILE* input, FILE* output, SymbolTable* symtbl)
Note: There are characters. I mean, normal codes No pseudo. The symbol table contains position of labels.

9. Symbol Table

10. Relocation Table

11. Assembler-Proj1.1 pass2 TODO list
Check if invalid inst
Use label position to generate numbers.
Record relocation things to reltbl
int pass_two(FILE *input, FILE* output, SymbolTable* symtbl, SymbolTable* reltbl)
Note: the pc is with suffix 00 or not

12. ???

13. After Assembler-Proj1.1 The object file with header Code (number) Data
Relocation table
Symbol table
Debug infos

15. Linker-Proj1.2 TODO list
Object code files, information tables -> Executable code
Briefly. Combine multiple object file to a single one
Use relocation table and symbol table.
Merge text/data segment
Create absolute memory addresses
Modify & merge symbol and relocation tables
Edit Addresses in relocation table
Output executable of merged modules(instructions + data + details)

16. Loader project2 part ./a.out
Read instructions allocate space for program
Copy data to memory
Copy args to stack
Init register
Execute

17. Logisim based CPU

18. Guest lecture: Pthread
Yifan