example 18.1. The simplest assembly procedure#PURPOSE: Exits and returns a# status code back to the Linux kernel# #INPUT: none# #OUTPUT: Returns a status code. This can is viewed# by typing## Echo $?## after running the program# #VARIABLES: # %eax holds the system cal L number# %EBX holds the return status#. Section. Data. Section. Text. Globl _START_START:MOVL $,%eax# this is the Linux kernel command# number (System call) for exiting# a program movl $4,%ebx# This is the status number
. The following compares its advantages and disadvantages:
Advantage: assembly languages can express very underlying things.
Registers and I/O can be directly accessed;
The code can be executed very accurately;
You can compile code that is more efficient than the general compiling system;
It can be used as an interface of different languages or standards.
Disadvantage: assembly language is a very low-level language.
It is very lengthy and monotonous, and can be realized during programming
Inline Assemblerthe compiler includes a powerful Inline. With it, assembly language instructions can is used directly in C and C + + source programs without requiring a separate ass Embler program. Assembly language enables optimizing critical functions, interfacing to the BIOS, operating system and special hardware, a ND access capabilities of the processor that are not available from C + +.
It supports both 16-bit and 32-bit code generation in all memory models.
What ' s in this chapterbasic
the program compiled all the bytecode. File structure see.Assembler SeriesNow we can start designing the assembler. This assembler will be able to compile the compiled source program that we have written and write it to a binary bytecode file that can be run by the virtual machine. The assembly file format is as follows:指令>空白>操作数>[空白]换行>Where the contents of the square brackets [] are optional.
No
Programming: Start the program to implement a very simple function in the center of the screen; print a line of strings (assembler +c+red hat Linux implementation)assembly language writing:Boot.asm Startup program code:; Our launcher implements very simple functions in the center of the screen; Print a line of stringsorg 07c00h; org directive explicitly tells the compiler that my program start address is 07c00h, not; the original 00000; int assembly d
addresses are fixed and can be queried from the STM32 manual, or calculated based on St's official library files.2, allocating stack spaceStack_size EQU 0x00000400Area STACK, Noinit, READWRITE, align=3Stack_mem SPACE Stack_size__initial_spThis paragraph is excerpted from the startup file. To read this code, first understand the two commands.Area Command : The area Command instructs the assembler to assemble a new code snippet or data segment. Segment
memory in the system. Each process has its own independent space in the multiple-segment mode, and the boundary pair has its own space.
In addition, there are paging modes
Assemble base elements
Constants
Default decimal, can add suffix 10H, 10D, 10O, 10B
available basic integer Expressions
() +-*/MOD
character and string constants
' A ', ' a ', ' Goodnight ', ' Goodnight '
reserved word instruction mnemonics, MOV ... Pseudo-directive attribute BYTE ... operator predefined symbols, @data, re
Master the basic Arm assembly instructions, to write a simple arm assembler program, but also have to master the basic Arm Assembly pseudo operation (Directive). Now let's look at a simple assembler that calls the subroutine to complete the addition operation.
1. FileName: Test.s2; function: realize two registers add together3 area example,code,readonly; declaring code Snippets Example4 ENTRY; Logo Program
[Article Title]: Unemployed entertainment-Ida reverse engineering entry (2)-assembler (1)[Author]: layper[Author mailbox]: layper2002@yahoo.com.cn[Author Home Page]: http://blog.csdn.net/layper/[]: Search and download by yourself[Author's statement]: I am only interested and have no other purpose. For errors, please enlighten us!--------------------------------------------------------------------------------[Detailed process]This is the second article
Automatic Object Assembler
1. Some friends say that it is very troublesome to encapsulate data into objects. The favorite thing about hibernate is that it is easy to operate data. What I want to talk about is that the framework is an advanced encapsulation of basic operations. Just as data is encapsulated into objects and nothing is left blank, an automatic object assemble is simply implemented. You can study it. Of course, if you are interested, you
first, how to pass the parameters
When the assembler calls the C function, the function's entry parameters are routed using stacks, and the parameters are passed from right to left. That is, the last (rightmost) parameter of the function first goes into the stack, and the first parameter to the left is finally put into the stack, then executes the call instruction to invoke the C function. ii. Elimination of parameters
After the C function returns, t
The compilation language compiler we used this time was developed by the author of the original book, called NASK. Many syntaxes are very similar to the famous compilation language compiler NASM. Because the author of the original book did not give any difference, it cannot be different here! Now we only need to use the DB commands in the assembly language to write an "Operating System. The DB command is short for "define Byte". It writes 1 byte of ul
Since the vast majority of domestic programmers have previously only been exposed to the Intel format of assembly language, there is little or no contact with the-T assembly language, although these assembly codes are Intel-style. But in Unix and Linux systems, more use of the or T format, both in the syntax format is very different, in fact, can use the original assembly of ideas to solve the problem, as long as the following two differences:First, in the/T assembly format, the register name is
Masmfor windows integrated development environment compiling Assembler
Recently I have been studying compilation, and I used a software called "MASM for Windows integrated development environment". However, I found that there is little information about the software. For those who just learned compilation, I have found a lot of information. The following describes the tool and two basic assembly programs.
I. Use of software
The following are the basi
*Map
Map
Defines the first address of a structured memory table. In this case, the location counter of the memory table
{Var}
Set to this address value
{Var}
Is the built-in variable of the assembler.
^
And
Map
Synonymous
.
Pseudocommand format:
Map expr
,
{Base_register}
Where:
Expr
Numeric expression orProgram. When the command does not contain
Base_register
,
Expr
It is the first address of the structured
Assemble the source program structure assembly instructions: There is a corresponding machine code instructions, can be compiled into machine instructions, and ultimately executed by the CPU. Pseudo-directive: instructions executed by the compiler, no corresponding machine code, compiler is related to the compiler according to pseudo-instructions. Segment: A assembler is made up of multiple segments. Used for storing code, data, or as a stack space, r
Csapp, the third edition of "in-depth understanding of computer systems: A programmer's Perspective", is a good book, but it needs to be quite basic in reading. Moreover, some of the expressions are not straightforward.For example, the No. 463 page mentions why the assembler sets the initial value of the reference in the call instruction to-4 (for 32-bit systems). Explained vague later. In conjunction with the expansion of the Code calculation formula
ARM Assembler Programming Simple example
1). Basic Concepts
(2) Register such as R0, R1 and other arm assembly programming is essentially for the CPU register programming.
(3) Instruction code direct control Cpu such as MOV includes jump instruction, data processing instruction, multiplication instruction, PSR Access instruction, loading or storing instruction, data exchange instruction, shift instruction, etc.
(4) Pseudo-operation acts on the
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