linux kernel development robert love

is too high, and your Sun Wukong has 72 changes, and the Erlang gods have 73 changes. If there is a problem, it doesn't matter. Look for Tao brother. Now I will teach you a few tricks for you to learn from time to time: Do you want to compete? Well, the general principle is to prevent you from competing: ensure that when an execution unit accesses shared resources, access to other execution units is prohibited, the competition will be killed in the bud. This is the legendary mutex access to s

To understand the segment information of Linux kernel code, you need to understand the encoding attribute or defined function or number of GCC's _ attribute, __attribute _ is mainly used to change the declared data features. It has many subitems used to change the characteristics of the target object. For example, for a function, noline will prohibit inline extension, noreturn indicates that no return value

Introduction to the 1.Linux kernelHow 1.1.Linux systems FormKernel space (Kernel spaces) + user spaceUser space = User program + C language Library (example: GNC C Libraries)Kernel space = Kernel + system call Interface (INTERFACE) + architecture-related codeLinux system is

Linux Kernel series-HelloWorld and linuxhelloworld for Operating System Development Org 07c00h; a pseudo command that tells the compiler program to be loaded to mov ax, csmov ds, axmov es, axcall DispStr at 7c00; call the display string routine jmp $; infinite loop DispStr: mov ax, bootMessagemov bp, ax; ES: BP = string address mov cx, 16; CX = string lengths mov

Linux Kernel series-11. ELF format for operating system development, linuxelf Shows the structure of the ELF file: The ELF File consists of four parts: ELF header, Program header table, Section (Sections), and Section header table ). In fact, a file does not necessarily contain all this content, and their locations may not be arranged as shown in this arrangemen

, DA_DRWA+DA_32+DA_DPL3; Stack segment ring3[section. S3]align32[bits32]label_stack3:times db 0topofstack3equ$-label_stack3-1; END of [section. S3]; Codering3[section Ring3]align32[bits32]label_code_ring3:movax, Selectorvideomovgs, Axmovedi, (+ 0) * 2movah, 0Ch Moval, ' 3 ' mov[gs:edi], axjmp$segcodering3lenequ$-label_code_ring3; END of [section. Ring3]EXECUTE as follows:The Red 3 was printed, indicating that our transfer from RING0 to Ring3 was successful. Next Test the use of the call door.Cha

loader.bin, you need to execute "$ (ASM) $ (asmflags)-o [email protected] $2.loader.bin relies on the following files:A.loader.asmB.include/load.incC.include/pm.incD.include/fat12hdr.inccommand is executed when at least one of them is newer than loader.bin.[email protected] represents the first name of target;$Nasm-o Loader.bin Loader.asmIn makefile it is easy to notice that not only the Boot.bin and loader.bin two files have colons behind them, everything, clean, and all have colons, but they

"Mr. Wang, today we will talk about AIO and device drivers. This is the last section of device-driven notifications and asynchronous IO. Next time we will begin to talk about more advanced things, such as interruptions, clock, etc" In the Linux kernel, each IO request corresponds to a kiocb struct, and its ki_filp Member points to the corresponding file pointer. Through is_sync_kiocb, you can determine that

we went to install Hello.ko, there was this error: undefined symbol:This is because of the extern int function () in our program, which is not present in the system. Does that have to Insmod Function.ko first!?Although the system has already appeared function functions, but the system still cannot find. You can see that the error is still there.This is the problem with module export: When we are going to use a variable inside a module, the function must be exported using a symbol. That is, the

the device driver can be received by this process. 2) use the f_setflio control command to set the device file to support fasync, that is, asynchronous notification mode. 3) connect signals and signal processing functions through signal. Of course, if you know about the Linux/Unix signal mechanism, you may ask why you didn't say the sigaction function. In fact, it doesn't matter. It's almost helpful. If you want to know it, read p261. With th

GDB provides a Python scripting interface, and the kernel provides some useful scripts to simplify the debugging steps of the kernel. Set up Create a virtual machine for QEMU/KVM. Enable config_gdb_scripts when compiling the kernel, but do not enable config_debug_info_requced. If your machine architecture supports config_frame_pointer, this option is also turned

programming in Linux. Of course, here is also a bit. How can we operate it, I want to sell a token to the next section. A zone in the memory used for data interaction with peripherals is called a DMA buffer. When the device does not support scatter/gathercsg, the DMA buffer must be physically connected. For an ISA Device, Its DMA Operation can only be performed in memory below 16 Mb. Therefore, gfp_dma is used when applying for a DMA buffer using

. Switch to Protected modeJust set the No. 0 position of the register CR0 to 1 on the line. 66-68 rows6. Real access to protection modeIn jmp DWORD selectorcode32:0, this line is the code that really goes into protected mode, SELECTORCODE32 is a segment selector, and the segment selector is to find the corresponding segment descriptor to find the corresponding Subgrade address. The format of the segment selector is as shown inStarting at bit 3 is the index of the segment descriptor, which, after

Mr. Wang, have you heard of AIO? Foreigners, in this way, always love short form, the result is we don't know. The so-called AIO is asynchronous input/output. The basic idea is to allow the process to initiate many I/O operations without blocking or waiting for any operation to complete, the process can retrieve the results of an I/O operation later or when it receives a notification that the I/O operation is complete. "Well, why did you take a less

1. Linux kernel modules are not compiled into kernel files (zimage,bzimage), but are dynamically installed and uninstalled during runtime2, the kernel module includes a few parts: main part design, compile kernel module, install uninstall NHMK, optional use (module declarati

follows :#. /testseconds after Open/dev/second 1 seconds after Open/dev/second 2 .... take another interrupt and check whether the kernel output operations are as follows: # tar-F/var/logs/messagecurrent jiffies is 18569 current jiffies is 18669 Current jiffies is 18769.. .. "John, the interruption and clock of the Linux device driver have been completed, and it has come to an end. I don't know if

My environment is configured as follows:Install virtual machine VMware10.0.1 on PC, CentOS6.5 installed on virtual machine, note virtual machine vmware above network configuration choice is bridge modeInstall SECURECRT6 on your computer windows, log in to CentOS in the virtual machine beforehand, query the IP address of the machine, and log in to CentOS via SECURECRT.Why log in to CentOS via SECURECRT? Because in the CentOS directly running terminal or ALT+F1~5 mode into the command line, the di

. Module version (optional)Module_version ("V1.0");5. Module alias (optional)Module_alias ("A simple module");6. Module parametersThe module parameters are specified by the macro Module_param, which is used to pass parameters to the module when the module is loaded.Module_param (Name,type,perm)Name is the type of the parameter for the module, and Perm is the access to the module parameter.Permissions.Type common values:BOOL: Boolean int: Integral type charp: String typePerm Common values:S_irugo

A kernel symbol table is a function and a variable that represents a public access. Global functions and global variables similar to the application.The Common kernel symbol table is the System.map file generated by kernel make, which is used by insmod to interpret undefined symbols in the module. The Public kernel sym

MkdevThe function converts the primary and secondary device number to the dev_t type main device number major the secondary device number minor Header file Macros defined in Mkdev (int major,int minor) Macro definition #define MKDEV (Major,minor) ((major) Parameters Major main equipment number Minor is the secondary device number return value Successful execution of a device number that returns the dev_t type Annotations: 1 Linux D