Linux ASM + C (INT 0x80)

Blog address from: http://blog.sina.com.cn/s/blog_79b802790100q8tt.html

 Finally, I tried to use ASM in Linux.AndC and generate the-ELF File.
 Functions in a program call each other using a stack.

And interruptInt0x80But it is not clear. It is clear that this is a BIOS interrupt and multiple functions can be implemented. The eax selection function is used. When eax = 4, it is the screen output, EBX is the number of outputs, and ECx is the character length, edX is the character content.

The parameter passing follows the following parameters first to the stack.

 Foo. ASM                                                                                                                                                   
Extern choose

[Section. Data]

   Num1  Dd3
   Num2  Dd4

[Section. text]

   Global _ start
   Global myprint

_ Start:

       Push  DWORD [Num1]
       Push  DWORD [Num2]
       Call  Choose
       Add   ESP, 8

       MoV   EBX, 0
       MoV   Eax,