3ddr ram

significance.From the above analysis can be seen bootloader in the process of operation, although the initialization of the system and the execution of user input commands, but its most fundamental function is to start the Linux kernel, let us further analysis of the bootloader and Linux kernel in the embedded system of the relationship and role.Bootloader1, bootloader Basic overviewBootloader is the bootloader of embedded system, it is the first program running after power on the system, it ac

-> the boot sequence is hdisk0 first. If it fails, hdisk1# Bootlist-M Service cd0 rmt0-> CD-ROM first in maintenance mode, then tape The structure of the disk boot area is as follows:Boot Record | vgda | softros | bootexpand | compressed kernel | compressed Ram filesystem | base ODM | rest of the root disk (hd2, hd4, hd9var, etc) Boot Record: Boot Record. Is a 512-byte record that records the size and location of the boot image program. The ROS (ROM O

port from CPU control to startup of the CE kernel. 2. oeminit Generally, all peripheral hardware, system clock, RTC (real time clock), and kitl (kernel independent transport layer) are initialized in oeminit ). For example, the oeminit function of the IMG platform associates all IRQ and interrupt IDs first, and then initializes the PCI bus, network adapter, power management, PIC (Programmable Interrupt Controller), and system clock, finally, check whether there is extended memory. In addition,

function. Generally, the vast majority of virtual addresses do not correspond to physical memory. The actual physical memory needs to be provided by the operating system before these address spaces can be used. The actual physical memory provided for the virtual address is called ldquo; Submit rdquo; (COMMIT ). Under different circumstances, the physical memory types submitted by the system are different, Either ram or Virtual Memory Simulated by t

U-boot, unless it is debugged in RAM, typically executes a piece of code from Flash, then moves the code and data stored in Flash into RAM and jumps to ram for execution. Of course, this should also be the general bootloader of the implementation of the way,everyone is similar, but the memory planning (stacks, heaps, and so on) of each bootloader is not the same,

task 218 Task Switching 192 Set events 89 Send signal 72 Send message 117 Memory Requirements Task Type Performance Code size Kernel RAM Space Task RAM Space TaskStackSize + 52 bytes RAM space of the mailbox MaxMessages * 4 + 16 byte

I. principle and structure of a look-up table The PLD chip with this structure can also be called FPGA, such as the acex, Apex, Spartan, and Virtex series of Altera. Look-up-table (LUT) is essentially a ram. Currently, FPGA uses 4-input Lut, so each LUT can be regarded as a 16x1 RAM with 4-bit address lines. After you describe a logical circuit through a schematic or HDL language, the PLD/FPGA develo

Chapter 2 Java card objects In Java card technology, jcres and applets Express, store, and operate data by creating objects. Applets uses Java Programming Language. The applets running on the card is the object of the Applet Class. Objects on the Java card platform follow the Java programming rules: All objects on the Z-Java card platform are class instances or arrays. They all have the same root class. Java. Lang. object. Z fields in a new object or components in a new array are s

, but only the virtual address space provided by the operating system using the CPU memory paging function. Generally, the vast majority of virtual addresses do not correspond to physical memory. The actual physical memory needs to be provided by the operating system before these address spaces can be used. The actual physical memory provided for the virtual address is called ldquo; Submit rdquo; (COMMIT ). Under different circumstances, the physical memory types submitted by the system are di

With the release of Linux 2.4, a large number of file systems are possible, including reiserfs, XFS, gfs, and other file systems. These file systems sound really cool, but what do they actually do, what do they do well in, and how can they be safely used in a Linux product environment? Daniel Robbins answers the above questions by showing you how to create these advanced file systems in a Linux 2.4 Environment. In this section, Daniel briefly introduces tmpfs, a VM-based file system, and introdu

device, and a standard image virtual disk (read-only) that is assigned to a collection of production devices and shared by that collection. For standard image virtual disks, the write cache options include caching on the server disk, caching on the device's hard drive, or caching in device RAM.650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M00/72/B7/wKiom1Xr26vTmbBiAAJXcJOmwyI174.jpg "title=" 2.png " alt= "Wkiom1xr26vtmbbiaajxcjomwyi174.jpg"/

follows:MAPREDUCE.MAP.MEMORY.MB 4096MAPREDUCE.REDUCE.MEMORY.MB 8192Description: These two parameters specify the memory size of the two tasks (Map and Reduce Task) used for MapReduce, and their values should be between the maximum minimum container in RM. If not configured, it is obtained by the following simple formula:Max (Min_container_size, (total Available RAM)/containers)The general reduce should be twice times the map. Note: These two values c

following small series from the following aspects to the introduction of FPGA simple knowledge.How FPGAs workThe FPGA incorporates a concept such as a logic unit array LCA, which includes a configurable logic module, CLB, output input module IOB, and internal wiring three parts. The FPGA uses a small lookup table (16x1ram) to implement the combinational logic , each lookup table connected to the input of a D trigger, the trigger to drive other logic circuits or drive I/O, This makes up the basi

I. How cache works The principle of caching is that when the CPU reads a piece of data, it first looks up from the cache, reads it immediately after it finds it, and sends it to the CPU for processing. If no data is found, it will read data from the database at a relatively slow speed. It is handed over to the CPU for processing, and then the corresponding data blocks in the database are transferred to the cache. Later, when the same data is read again, it can be read from the cache, which is fa

Note: Based on the USB download method, mlc nand Flash is k9g8g08u 1. File description of multiple xip Mode In multiple xip mode, the generated files include chain. Bin, chain. lst, NK. Bin, xip. bin, and xipkernel. Bin, as shown in: Figure 1 2. The order in which eboot downloads multiple xip image files Download the chain. LST file. The chain. LST file defines which binfiles to download to flash and the order in which these binfiles are downloaded. We use ultraedit to open the chain. LST file

build file systems such as jffs2.* Ramdisk compresses the created rootfs and writes it to flash. during startup, the bootloader loads it to ram, decompress it, And then mounts it /. This method is simple, but the file system in Ram is not compressed, so it needs to occupy a lot of rare resources in embedded systems Ram.Ramdisk uses memory space to simulate hard disk partitions. ramdisk usually uses the com

");Print ("$hostname \ n");Add the module in Nginx (nginx configuration directory,/sites-enabled/default, included in the server, otherwise it will be an error)Location ~ ^/nginx_status {Stub_status on;Access_log off;}Re-start NginxBuild configuration fileCfgmaker [email protected]--output/root/mrtg.cfgModify ConfigurationWorkdir:/HOME/MRTG/MRTG (working directory)and add content to itTARGET[CPU]: '/home/mrtg/mrtg.cpu 'MAXBYTES[CPU]: 100OPTIONS[CPU]: Gauge, nopercent, growrightYLEGEND[CPU]: CPU