Tools for viewing target and binary files
1.readelf– target file with "Gcc-a a.c"-> a.o
2.objdump– View target file && binaries "objdump-h a.0" process address space
1.task_struck structure that stores information about the process
2. Runtime address space structure
Virtual memory-all processes share one operating system code
The virtual address points to the real address, and he just represents the relative offset between the ground
3. The establishment of the process
Create virtual address space-mapping (memory copy)-code copy
4. Loading mode:
Overlay Mount (OBSOLETE)
Page mappings: a.out-> virtual address space-> physical Space (page) system call
Run-time Privilege level
Dpl:
| 0 |
1 |
2 |
3 |
| OS |
Driven |
Driven |
User |
| Any |
A paragraph |
A paragraph |
No |
Memory access (Physical address)
Disadvantages of system calls:
Poor portability
Workaround:
Run-Time Libraries
