3ddr ram

entry001bh -- T1 overflow interrupt entry0023 h -- Serial Port Interrupt entry002bh -- T2 overflow interrupt entry Internal data storage RamThere are two physical areas: 00 h ~ 7fh is the ram and SFR areas in B.Function: Used as a data buffer. Is the spatial structure of the 8051 microcontroller memory Program memory A microprocessor can intelligently execute a certain task. In addition to their powerful hardware, they also need the software they ru

In Linux, there is a special feature-initializing the memory disk initrd (initial RAM disk) technology, and the kernel supports compressed file system images. With these two functions, we can enable the Linux system to initialize the memory disk from an early stage and mount part of the system memory as the root file system. Ramdisk allocates a portion of the memory as a partition and uses it as a hard disk. For programs that are constantly used durin

Flash memory, also known as Flash, is a commonly used type of memory in routers. It is a read-write memory that can still be saved after the system restarts or shuts down. In Flash, the iOS (Router operating system) currently in use is stored.There may be a variety of memory in the router, such as Flash (Flash), DRAM (dynamic memory), and so on. Memory is used as storage configuration, router operating system, routing protocol software and so on. In low-end routers, the routing table may be stor

Author: EasyLife http://www.mike.org.cn/blog/index.php?load=readid=635 In the Linux operating system, there is a special feature-Initialize the memory disk INITRD (INITial Ram disk) technology, and the kernel supports compressed file system images. With these two features, we can start the Linux system from a small initialization memory disk and mount part of the system memory as the root file system. RAMDisk is to allocate part of memory as a partiti

paging unit is enabled. Starting with 80386, all 80x86 processors support paging, which is enabled by setting the PG flag of the CR0 register. When pg=0, a linear address is interpreted as a physical address.From 80386, the paging unit of the Intel processor handles 4KB of pages. The 32-bit linear address is divided into 3 fields:Directory (directory)-Maximum 10 digitsPage table (table)--10 bits in the middleOffset-Minimum 12 digitsWhen a process is running, you must have a page directory assig

the CPU, memory, and disk drive used by the database server. The second is to optimize the queries sent to the database. This article discusses hardware-side performance tuning. Query optimizations can be done through SQL commands such as CREATE INDEX, vacuum, vacuum full, ANALYZE, CLUSTER, and EXPLAIN. These are discussed in "Postgresql:introduction and Concepts" in http://momjian.us/main/writings/pgsql/aw_pgsql_book/. To understand the hardware tuning problem, it is important to understand wh

Quartus ii lpm User Guide FIFO Directory Description-2- Summary-3- Chapter 1 Introduction to FIFO configuration-4- 1.1 how to configure the required FIFO-4- 1.2 input/output port-5- 1.3 Timing requirements-8- 1.4 output status tag and latency-8- 1.5 avoid sub-steady state-9- 1.6 impact of Synchronous Reset and Asynchronous Reset-9- 1.7 different input/output bits-10- 1.8 constraint settings-10- Chapter 2 Design Example-11- 2.1 design instance overview-11- 2.2 System Simulation Analysis-11- 2.2.

Bootloader and other programs can find the image information through TOC. This offset value defines a global pointer ptoc in oal to ensureStorage, romimage can use this pointer to locate and fill in the content of TOC. During compilation, the ptoc variable of nk.exe is 0 xffffffff. When NK. Bin is producedWait, romimage will do the following: 1. initialize nk.exe, and then modify 2. Generate TOC content and find the place where the image file is stored with TOC 3. Find the ptoc pointer and conf

the knowledge above, we can set relevant parameters according to our actual situation. Of course, we also need to continuously check and adjust the parameters during the testing process.The following are the configuration suggestions provided by hortonworks:Http://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.1.1/bk_installing_manually_book/content/rpm-chap1-11.html4.1 Memory Allocation Reserved Memory = Reserved for stack memory + Reserved for HBase Memory (If HBase is on the same node)The tota

, the ROM boot program is moved to Ram_high_adrs by the system boot code. The ROM boot program then starts running, loads the VxWorks image into Ram_low_adrs, and jumps to the VxWorks image mount point.The rom-based VxWorks image is fully moved into RAM when the BSP is initialized, including code snippets and data segments. After the copy execution is complete, the system control is transferred to the initialization code of the VxWorks image in RAM.Ro

Article Title: Embedded System BootLoader technology insider. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source. 　　 1. Introduction Running GNU/Linux systems on dedicated embedded boards has become increasingly popular. An embedded Linux system can be divided into four levels from the software perspective: 　　 1. boot the loader. Includes the boot Code (optional)

The general flow of software projects is: design, coding, tuning, on-line. Tuning process often encounter system performance is not enough, but the performance is not good also normal, if you write code performance on the cow X a mess, may also not need so many so-called best prticace experience summed up.Recently saw a book, "DevOps Troubleshooting", the book is very thin, the content may be in other books are explained, but he summed up very well, may be the system after the failure of the eli

the beginning.- S: displays memory-related statistics and the number of system activities.delay: Refresh time interval. If not specified, only one result is displayed.Count: number of refreshes. If you do not specify the number of refreshes, but the refresh interval is specified, the number of refreshes is infinite.- D: displays disk-related statistics.- P: display specified disk partition statistics- S: displayed using the specified units. The parameters are K, K, M, M, respectively, represent

typically initialized in Oeminit, the system clock is initialized (systems tick) and the RTC (Real Time Clock), and the initialization kitl (Kernel Independent, transport Layer). For example, the Oeminit function of the I486 platform, which associates all IRQ and interrupt IDs first, then initializes the PCI bus, network adapter, power management, PIC (programmable interrupt Controller), system clock, and finally detects extended memory. In addition, if the OEM is to enhance functionality by OA

annoyances in such systems. Performance. In real address mode, switching and memory ing are usually not supported, and the system cannot be expanded. Crashes and crashes are common in such systems. How virtual addressing works In virtual addressing mode, every program is allocated a private address space that is completely isolated from other processes 'address spaces. For example, if address0x4000aef6In process a points to a certain variable, the same address in process B may point to some ot

S3C2410 supports direct start from NAND Flash, so NAND bootloader is used. Most NAND bootloaders are divided into nboot and eboot. Code dependent on the CPU architecture is put in nboot, which is usually implemented in assembly language + C language; while eboot is usually implemented in C language, which can implement complex functions, in addition, the Code has better readability and portability.Nboot: Hardware Device initialization: Block all interruptions. You can write the Interrupt

;----------------------------------------------------------------------- Nk.exe $ (_ targetplatroot) \ target \ $ (_ tgtcpu) \ $ (wincedebug) \ eboot.exe eboot The value 0x000000fb in NK. Bin, that is, there is a 251toc entry in NK. Bin, that is, there are a total of 251 modules (DLL or EXE ). 6) ulramstart Indicates the starting address of the RAM program memory area of the image file. Here, the RAM progr

offset value, so Bootloader and other programs can find the image information through TOC. This offset value defines a global pointer ptoc in oal to store it. romimage can use this pointer to locate and fill in TOC content. During compilation, the ptoc variable of nk.exe is 0 xffffffff. When NK. Bin is produced, romimage will do the following:1. initialize nk.exe, and then modify2. Generate TOC content and find the place where the image file is stored with TOC3. Find the ptoc pointer and confir

Title: Implementation of hive registry + binfs on the s3c2440a Platform Similar posts can also refer to http://bbs.driverdevelop.com/htm_data/48/0709/106094.htmlToday we will summarize some implementation processes and principles. My example is based on Samsung s3c2440a + Samsung onenand + wince5.0, and the Development Platform is platfo.Rm Builder 5.0. First, the image based on Ram register can run normally.The file system is provided for users to s

files are required. For this big data file "service", wafl uses the upper-layer inode to point to the lower-layer inode. For example, when the file size is small to less than 4 kb, the file can be directly stored in inode. Save space. Thinking: in fact, Microsoft's inode only contains the address of the first data block of the file, and then the first data block contains the second data block. Therefore, inode does not need to be so large. You only need an inode of the normal size. Why does waf