Like many of us, I spent yesterday updating a whole lot of systems to mitigate the Meltdown and Spectre attacks. As I understand it, it is necessary to install two packages and reboot: kernel-3.10.0-693.11.6.el7.x86_64 microcode_ctl-2.1-22.2.el7.x86_64 I have two CentOS 7 systems on which I've installed these packages and rebooted. According [...] read more
Edit: I updated my question with the details of my benchmark For benchmarking purposes, I am trying to setup 1GB pages in a Linux 3.13 system running on top of two Intel Xeon 56xx ("Westmere") processors. For that I modified my boot parameters to add support for 1GB pages (10 [...] read more
I want to get into PAPI. I have Version 5.3.2.0 on Debian GNU/Linux. papi_avail just tells me that no hardware events are available: $ papi_avail Available events and hardware information. -------------------------------------------------------------------------------- PAPI Version : 5.3.2.0 Vendor string and code : GenuineIntel (1) Model string and code : Intel(R) Core(TM) i3-5010U [...] read more
I am trying to split my audio recording with android mediarecorder into multiple files, but whenever I set the next output file, I got an illegalstate exception. Here's the code: private void getMediaRecorderReady(String filePath, FileDescriptor nextFile) { bufferSize = 88200; recorder = new MediaRecorder(); recorder.setAudioSource(MediaRecorder.AudioSource.MIC); recorder.setOutputFormat(MediaRecorder.OutputFormat.AAC_ADTS); recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC); recorder.setAudioEncodingBitRate(64000); recorder.setAudioSamplingRate(44100); recorder.setAudioChannels(1); [...] read more
Basically I've followed the instructions here http://sig9.com/bochs-grub to create a bare image file which does nothing but lets the BIOS start GRUB. The problems are: * The kernel I am writing will be 32-bit, using http://www.jamesmolloy.co.uk/tutorial_html/index.html for a start, but my host (physical) machine is x86_64 with bochs configured like [...] read more
I am following brokenthorn OS development series, until now I am able sucessfully run bootloader stage1 but there is some issue with loading second stage bootloader from FAT12 floppy in bochs emulator on linux machine(ubuntu 16.04) (It works fine in virtual box though). Here is my stage1 boot loader: bits [...] read more
I am hooking the function 'NtQueryDirectoryFile' to hide folder in the system , my code as below. #include "stdafx.h" #include <windows.h> #include <stdio.h> #include "MinHook.h" #include <shlwapi.h> #include <winsock2.h> #if defined _M_X64 #pragma comment(lib, "libMinHook.x64.lib") #elif defined _M_IX86 #pragma comment(lib, "libMinHook.x86.lib") #endif #define NT_SUCCESS(Status) ((NTSTATUS)(Status)>=0) typedef LONG NTSTATUS; #define STATUS_SUCCESS [...] read more
I am trying to read excel file with pandas. df=pd.read_excel('abcd (xyz-9) Interim Report 01-03-18.xlsx') which gives me file not found error. If I remove brackets and rename file to 'abcd Interim Report 01-03-18.xlsx', then it works fine. I tried renaming with shutil but it gives me the same error shutil.copyfile('abcd [...] read more
I have used the cpuid | grep -i tlb command on the terminal to try to determine the exact number of page table entries (and the corresponding page-sizes) being used by the machine. This is what I've got. cache and TLB information (2): 0x63: data TLB: 1G pages, 4-way, 4 [...] read more
For my application (SpMV) I have more data cache misses (PAPI_L1_DCM) than total cache misses (PAPI_L1_TCM) in level 1 cache. How can that be? For Level 2 the values are ok. That is, what the PAPI counters offer: [PAPI_L1_ICM ][PAPI_L1_DCM ][PAPI_L1_TCM ][PAPI_L2_ICM ][PAPI_L2_DCM ][PAPI_L2_TCM ] 1256 3388225 1442386 1007 2389903 [...] read more
I'm currently developing my bootloader, but I have problem. I use Bochs to test bootloader, I compile bootloader and make disk image with: rm disk.bin rm boot.bin rm post.bin nasm bootloader.asm -o boot.bin nasm postmbr.asm -o post.bin cat boot.bin post.bin > disk.bin This is bootloader.asm: [BITS 16] ;Tells the assembler [...] read more
I'm building a small operating system and was using Qemu before which was working properly. Now I'm stuck on a Windows 10 machine and Qemu doesn't work well with GDB on this machine. I thought I'd try Bochs or Virtual box instead. The problem is that with both of these [...] read more
I examined the cpuid documentation and discovered 2 different documented ways of getting cache line size: 1. eax = 0x04, ecx = $cache_level In this way the cache line size at the $cache_level will be stored at EBX[11:0] bits 2. eax = 0x80000006 In this way the cache line size [...] read more
I'm trying to use RAPI to monitor the performance of my Xeon Phi code. I just compiled and installed a native version of RAPI follwoing the documentation. And the following list is what I get when I execute "rapi_avail" on my Xeon Phi which shall display all available events. Surprisingly, [...] read more
<?php /* File : smppclass.php Implements : SMPPClass() Description : This class can send messages via the SMPP protocol. Also supports unicode and multi-part messages. License : GNU Lesser Genercal Public License: http://www.gnu.org/licenses/lgpl.html Commercial advertisement: Contact info@chimit.nl for SMS connectivity and more elaborate SMPP libraries in PHP and other languages. [...] read more
I receive this error message: systemd[1]: Failed to mount cgroup at /sys/fs/cgroup/system: No such file or directory [!!!!!] Failed to mount API filesystems, freezing. I am using Linux kernel 4.19.78 and system v2.34. My aim is to activate IMA/EVM with EVM in mode 0x80000006, as per https://www.kernel.org/doc/Documentation/ABI/testing/evm. I have a [...] read more
basic network [https://i.stack.imgur.com/ibFOc.gif] I receive a default route via iBGP from R1. On both R2 and R3 I have default-information originate configured. On R4 I only see one default route in the OSPF database; either to R2 or R3. When I shutdown one of the links from R2 / R3 [...] read more
I am trying to use DES encryption/decryption on Google chrome. In my folder I have three files. 1. tripledes.js 2. mode-ecb.js 3. CryptoJS-DES.html The scripts in my html file is defined as follows :- <script type="text/javascript" src="tripledes.js"></script> <script type="text/javascript" src="mode-ecb.js"></script> and another script file which is :- function encryptByDES(message, key) [...] read more
I encountered a trouble during getting L3 cache info on Intel processors. Getting L3 line length on AMD is simple, like this: mov eax, 0x80000006 cpuid shl edx, 24 shr edx, 24 The same operation on Intels is much more complicated. I got that this might be done using this [...] read more