Linux compilation Hello world + debugging

. Section. Data # initialization variable output:. ASCII "Hello, world \ n" # the string to be printed. Data is the variable of the initialization value. Output is a tag indicating the start position of the string. ASCII is the data type. section. BSS # uninitialized variable, buffer filled by 0. lcomm num, 20 # lcomm is the local memory area, that is, the volume cannot be accessed .. Comm is the general memory area. . Section. text # assembly language instruction code. globl _ start # Start entry _ start: movl $4, % eax # The called system function, 4 is write movl $ output, % ECx # the string to be printed movl $1, % EBX # file descriptor. The screen is 1 movl $12, % edX # String Length int $0x80 # The display string Hello, world movl $0, % eax movl $ num, % EDI movl $65,1 (% EDI) # A's ASCII movl $66,2 (% EDI) # B's ASCII movl $67,3 (% EDI) # c ascii movl $ (% EDI) # d ascii movl $ (% EDI) # \ n ASCII movl $4, % eax # called system functions, 4: Write movl $ num, % ECx # The movl $1, % EBX # file descriptor to be printed. The screen is 1 movl $6, % edX # String Length int $0x80 # display the string ABCD movl $1, % eax #1 is to exit movl $0, % EBX # exit code returned to shell int $0x80 # kernel Soft Interrupt, exit system

Effect and debugging.-ststabs is used to generate debugging information.

 

Deepfuture-lx @ deepfuture-lx-desktop :~ /Private/mytest $ as-gstabs-O hello. O hello. s

Deepfuture-lx @ deepfuture-lx-desktop :~ /Private/mytest $ LD-O hello. o

Deepfuture-lx @ deepfuture-lx-desktop :~ /Private/mytest $./Hello

Hello, world

ABCD

Deepfuture-lx @ deepfuture-lx-desktop :~ /Private/mytest $ GDB hello

Gnu gdb (GDB) 7.1-Ubuntu

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License gplv3 +: gnu gpl Version 3 or later

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Reading symbols from/home/deepfuture-LX/private/mytest/Hello... done.

(GDB) List

1. Section. Data # initialized variable

2 output:

3. ASCII "Hello, world \ n"

4 # the string to be printed. Data is the variable of the initial value. Output is a tag indicating the start position of the string. ASCII is the data type.

5. Section. BSS # uninitialized variable, buffer filled by 0

6. lcomm num, 20

7 # lcomm is the local memory area, that is, it cannot be accessed outside of the compiler .. Comm is the general memory area.

8. Section. Text # assembly language instruction code

9. globl _ start # Start entry

10 _ start:

(GDB) Run

Starting program:/home/deepfuture-LX/private/mytest/Hello

Hello, world

ABCD

 

Program exited normally.

(GDB)