Tài liệu Linux Device Drivers-Chapter 7 : Getting Hold of Memory doc

... Chapter 7 : Getting Hold of Memory Thus far, we have used kmalloc and kfree for the allocation and freeing of memory. The Linux kernel offers a richer set of memory allocation primitives, ... 1:e00000002 477 8000 salma% cat /tmp/bigfile > /dev/scullv0; head -5 /proc/scullvmem Device 0: qset 500, order 4, sz 1048 576 item at e0000000303699c0, qset at e...

Ngày tải lên: 24/12/2013, 01:17

... to schedule execution of some tasks at a later time without resorting to interrupts. Linux offers three different interfaces for this purpose: task queues, tasklets (as of kernel 2.3.43), and ... giving coarser resolution. #include < ;linux/ delay.h> void udelay(unsigned long usecs); Chapter 6 : Flow of Time At this point, we know the basics of how to write a full-fe...

Ngày tải lên: 24/12/2013, 01:17

... 1 0: 565910 565269 IO-APIC-level aic7xxx 1 2: 889091 884 276 IO-APIC-edge PS/2 Mouse 1 3: 1 0 XT-PIC fpu 1 5: 175 9669 173 4520 IO-APIC-edge ide1 NMI: 69520392 69520392 LOC: 6951 371 7 6951 371 6 ... /dev/shortint bh after 5 50588804. 876 653 50588804. 876 693 50588804. 876 720 50588804. 876 7 47 50588804. 876 774 The actual timings that you will see will vary,...

Ngày tải lên: 24/12/2013, 01:17

... and to allow the creation of "generic'' kernels that can support a wide variety of hardware, Linux offers support for automatic loading and unloading of modules. To exploit this ... T master_init_module U printk_Rsmp_1b7d4 074 U request_module_Rsmp_27e4dc04 morgana% fgrep 'printk' /proc/ksyms c011b8b0 printk_Rsmp_1b7d4 074 Because the checksums added...

Ngày tải lên: 21/01/2014, 07:20

... number for the device, DEVICE_ NAME is the name of the device to be used in error messages, DEVICE_ NR returns the minor number of the physical device referred to by a device number, and DEVICE_ INTR ... the size of device blocks in bytes (it usually is 1 KB), the size of each minor device in kilobytes (not blocks), and the size of the hardware sector in bytes. MA...

Ngày tải lên: 21/01/2014, 07:20

... registers: Vendor id: 8086 Device id: 1223 I/O space enabled: n Memory enabled: y Master enabled: y Revision id (decimal ): 0 Programmer Interface: 00 Class of device: 0400 Header type: 00 ... function device: n Optional registers: Base Address 0: f1000000 Base Address 0 Is I/O: n Base Address 0 is 64-bits: n Base Address 0 is below-1M: n Base Address 0 is prefetch...

Ngày tải lên: 21/01/2014, 07:20

... Unit 7 Saving Energy Lesson 1: Getting started - Listen and Read Period 42 faucet ? Mrs. Mi Mrs/. Ha ... taking showers? 5. How many liters of water can a dripping faucet waste a month? 3. Why should Mrs. Ha get a plumber? 1. Why is Mrs. Ha worried? Lucky Numbers! 7 1 4 6 2 8 5 3 P.W S.E.C I ... showers. Mrs. Mi : + suggest s + V - ing Cách đưa ra...

Ngày tải lên: 30/11/2013, 09:11

... more of the kernel's software interfaces: Chapter 6, "Flow of Time" shows how time is managed in the kernel, and Chapter 7, " ;Getting Hold of Memory& quot; explains memory ... 1 :An Introduction to Device Drivers As the popularity of the Linux system continues to grow, the interest in writing Linux device drivers steadily increases. Most of Li...

Ngày tải lên: 24/12/2013, 01:17

... is declared and exported using the facilities offered by the headers of Linux 2. 0: static struct symbol_table skull_syms = { #include < ;linux/ symtab_begin.h> X(skull_fn1), X(skull_fn2), ... memory is allocated with vmalloc; see "vmalloc and Friends" in Chapter 7, " ;Getting Hold of Memory& quot;). The system call get_kernel_syms returns the ke...

Ngày tải lên: 24/12/2013, 01:17

... Design of scull The first step of driver writing is defining the capabilities (the mechanism) the driver will offer to user programs. Since our " ;device& quot; is part of the 6 lp 7 vcs ... top of the computer memory, each with a different personality. The scull source implements the following devices. Each kind of device implemented by the module is referred to as...

Ngày tải lên: 24/12/2013, 01:17