In the "thesis reboot" post, I brought back from the dead the dusty implementation of my master thesis. Seeing that it was still (almost) working, a week off work was planned to prepare its adaptation to the almighty OpenCL. This post summarizes what this week was all about.
TL; DR …
read moreHow to use Intel gdb-igfx to debug Intel GPU.
Everything starts with this article: Getting Started with Debugging with Intel® Parallel Studio XE 2016 [1]. unfortunately, the article is quite old now ("Last updated on August 25, 2015") and not really up-to-date anymore.
No, wait, there is a newer version …
read moreHow to have a function taking a callback as parameter?
You cannot use function pointers in OpenCL, even if they can be resolved during compilation.
It is not possible to write this (while it works in CUDA since the beginning):
void do_operation(const int* A, const int* B, int* C …How to make OpenCL memory allocation functions more like normal malloc/memcpy?
There is a problem with clCreateBuffer [1] is that it returns an opaque cl_mem object, rather than a good old pointer to the allocated memory.
cl_mem clCreateBuffer (
cl_context context,
cl_mem_flags flags,
size_t size,
void *host_ptr,
cl_int …Surprisingly, ARM Mali and Intel HD Graphics GPUs are similar in their design, in comparison to NVidia and AMD's designs.
On the left, ARM Mali [ARM], on the right Intel IGP [INTEL].
The similarity seems to stem from the two companies having …
What is a device, a compute unit (CU), a work-group, a work-item, a command-queue?
Playing with Intel OpenCL SDK and Etherneum mining
The Intel 6th-generation Core i7-6770HQ [1] is a neat little beast. Here are lspci [LSPCI], cpuinfo [CPUINFO], and clinfo [CLINFO] from an Intel NUC6i7KYK with Ubuntu server 16.04.
In …
Easy start: let us do CPU-only first
gputwigstack [1] is the result of a Master research about XML query processing on GPGPU [2].
Three steps:
- metadata generation from parsing XML file
- database creation
- query processing
Dependencies:
- scons software construction tool …
The Master thesis returns after seven years!
Seven years ago, I wrote my Master thesis [1] about using GPGPU for processing queries on XML trees.
Unfortunately, the result was not impressive. There were two major drawbacks:
So nice!
Just discovered that Intel provides a special version of GDB for debugging OpenCL kernels on their GPU [1]. What a great move!
Knowing Intel, I was already imagining that they would have a fully proprietary solution like the Intel debugger [2]. Fortunately, they deprecated it in 2013 in …
read moreHow many OpenCL compute unit has an Intel integrated graphic processor? aka How many divergent threads can be run in parallel?
On the quest to finding the OpenCL-compatible device having the largest amount of compute units (CU), it seems that around 30 CU, latest nVIDIA achitectures tend to feature a …
read moreConvert a Super Nintendo gamepad to an USB keyboard.
Ever wondered if you could type using a gamepad? On one side, a standard keyboard with its 100+ keys gives you direct access to most characters, but is not very confortable to use since you have to move your hands. On …
read moreHow to run firefox inside a docker container?
Adapted from [1] for debian:jessie-slim:
FROM debian:jessie-slim
RUN apt-get update && \
apt-get install -y firefox-esr && \
apt-get clean
RUN groupadd --gid 1000 user && \
useradd --uid 1000 --gid 1000 --create-home user
USER user
CMD /usr/bin/firefox-esr
Build the image …
How to clone an SD-card?
~$ sudo dd if=/dev/mmcblk0 of=image.img bs=4M status=progress 5783945216 bytes (5,8 GB, 5,4 GiB) copied, 81,031 s, 71,4 MB/s [...] 3835+1 records in 3835+1 records out 16088301568 bytes (16 GB, 15 GiB) copied, 247,23 …read more
Is it possible to use a JIRA server on a Scaleway C1 instance (bare metal ARM)? It is!
Did you know that you can buy an official license for a stand-alone JIRA server for only 10$? Even better, Atlasian actually donates the money to charity. Of course, this license …
Loop over all the members of an enumeration.
#include <iterator>
// Inspired from http://codereview.stackexchange.com/a/57699
template<typename T, T... args>
struct EnumIterAll
: public std::iterator<
std::input_iterator_tag, // iterator_category
T, // value_type
std::ptrdiff_t, // difference_type
const T*, // pointer
const T& // reference
>
{
static constexpr T values[] = {args...};
static constexpr std …Beware link wall ahead
Stumbling upon this page [1] ended up in a massive recurssive tree search. A stack of links where kept here.
Why not profiling your application by sampling backtraces using gdb? This intuitive idea is easily adapted to remote debugging as well. [2]
If …
How to record your screen into an animated gif with precise position and size?
I would like to create an animated gif with a size of 800x600px. The canva should contain a web browser in the top half, and a command-line terminal in the bottom half.
The Bosch XDK is a development platform centered around a set of Bosch sensors.
It features an EFM32 ARM Cortex-M3 based microcontroller.
| [1] | Bosch XDK, homepage, http://xdk.bosch-connectivity.com |
| [2] | Bosch XDK, API and docs (doxygen), http://xdk.bosch-connectivity.com/xdk_docs/ |
| [3] | Bosch XDK, Extention port pinout, http … |
How to debug an Atom processor over JTAG?
Official presentation of the "Intel JTAG debugger" is [1].
The standard Intel debug port is the 60-pin XDP (eXtended Debug Port). It extends JTAG with additional signals. This port also has a lower pin count variant: the 31-pin XDP-SSA (Second Side Attach …
read moreI don't want a fully fledged Eclipse project or depend on heavy Eclipse for anything.~
I don't know if you have the same feeling, but it doesn't look like a good idea to depend on one heavy tool for anything in your electronic project. Having easy-to-understand scripts for building or …
read moreThe USB specs are pretty large.
USB 2.0 specs [1]. Explanations [2].
Good description of the protocol [3].
Another source [4].
USB communications can be spyed with:
Software Wireshark (example video there [5]).
Hardware OpenVizsla An Open-source FPGA-based USB sniffer [6]... based of the Xilinx Spartan …
Buying a cheap analog multimeter at Conrad [1]... and having to repair it right out of the box!
The discret wire connecting the battery to the voltmeter line was broken. Fortunately, this analog multimeter is so simple that you can reverse engineer it easily and find the issue.
[1 …
Inside of the FLRe first complete prototype.
The microcontroller and FPGA boards are inserted facing each other in the (upper and lower) PCB guide grooves of the enclosure.
read more
| [1] | Ascel Electronic, AE20204 High Precision LC Meter, http://www.ascel-electronic.de/kits/6/ae20204-high-precision-lc-meter |
Simple example code to read the serial port under GNU/Linux
This code is expected to do something similar to
cat /dev/ttyUSB0
/* Reading from serial line
* written by vjp
* on 2015.03.12 */
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys …The FLRe automated test environment is meant to verify the validity of the FPGA dynamic reconfiguration code for all CLB (configurable logic block) of the Spartan-6 LX9 silicon die.
The FLRe client is compiled on the Raspberry Pi and sends requests over UART to the demo board, which processes the …
read moreDreaming of 0402? They are cute but damn small for handsoldering... or are they?
An USB connector... a voltage regulator and its two capacitors... on a 2x2cm PCB... nothing special so far, but if you flip the board...
... a SMD soldering challenge!
To light up …
Before starting a PCB design with the Xilinx Spartan-6, the most important document to read is [UG393] and [UG394].
Above: Required PCB Capacitor for the Spartan-6 LX9, [UG393] (v1.3, p. 14).
I discovered by reading this document, that ([UG393] v1.3, p. 22):
Capacitor package dimensions (body …
FLRe microcontroller paper PCB is ready!
All capacitors and resistors are in 0805 SMD size.
The alignment of the pin header footprints don't match with the enclosure constrains. (u_u)
read moreAll the footprints are ready. The boot mode (BOOT0 and BOOT1) will be set via a SMD DIP switch. The different power supplies will be accessible throught 1.27mm-pitch THT pin headers.
Now finally starts the fun of tidying everything of the board.
As it can be guessed …
The schematic of the FLRe STM32F4 microcontroller board has started.
An alternate supplier: http://uk.farnell.com/samtec/fts-110-01-f-dv/connector-header-1-27mm-smt-20way/dp/2308522 http://www.farnell.com/datasheets/1902580.pdf
Framatome Connectors International (FCI) http://uk.farnell.com/fci/20021121-00006c4lf/header-vert-1-27mm-smt-6way/dp/1865277 (faisait partie d'Areva, vendu 2005)
vjCanUsb is an USB-to-CAN interface featuring:
- one STM32F4 ARM Cortex-M4 microcontroller running at 168MHz (192KB RAM, 1MB flash). The Complete datasheet: [DH].
- two 3.3V LDO linear regulators, one for the digital as well as one dedicated to the analog power supply. USB power is filtered by a ferrite …
Little training before starting the PCB of the FLRe microcontroller board.
This shopping list refers to the following schematic: [1].
- 60.4R (~60R) VISHAY CRCW080560R4FKTABC
- 10kR VISHAY CRCW080510K0FKTABC
- 470R VISHAY CRCW0805470RFKTABC
- 22R VISHAY CRCW080522R0FKTABC
Above: the STM32F40x in its LQFP64 package cannot be used because it lacks FSMC support (unbound silicium pads, see [1] rev.4 p. 59). The LQFP144 poackage has full FSMC support, while the LGFP100 package has limited support: data lines only, and no address lines. Since the address lines will …
read moreJust got the PCB of the front panel...
The PCB matches the size of the metal cover of the enclosure with a surprising accuracy, and the result looks quite professional. About the PCB itself, most of the footprints are homemade, and one notices immediatly …
Dreaming of making a real-life product. Part two.
I decided to go for a stacked two-PCB design with a front panel also made as a PCB. The Hammond 1455 enclosure is available in 80x50x20mm (approx.) dimensions. If no large components are used on one side of each PCB, two PCBs …
read moreKiCAD does not support length matching, but there is to achieve some manual length matching using FreeRouting [1]. Unfortunately, FreeRouting has little documentation outside of the official manual [2].The idea comes from this blog post at Numato Labs [3]. Designing a Spartan-6 FPGA board with SDRAM, they needed to …
read moreDreaming of making a real-life product.
Prices are for one 50x100mm 2-layer (front and back) standard PCB with green soldermask
- http://www.jackaltac.com 37€ (includes 21% VAT), up to 100x100mm and top silkscreen, min track 0.15mm, min hole 0.3mm, made in South Africa and …
The FLRe project restarts... with my first coffee machine ever!
Plan for the next steps: build an automated test system, so as to validate the FLRe source code for each LUT in the Spartan-6 LX9 FPGA. The test system will be supervised by a Raspberry Pi:
Raspberry Pi -(uart)-> STM32F3 …read more
I have heard this sentence quite many times:
Vincent: "I studied computer science..."
Someone: "Oh! You must be good in mathematics then!"
No! There is no need of mathematics to design a computer. Maybe this misconception comes from the English word computer itself, which is based on compute meaning calculate …
read more
#include <stdint.h>
/* Base address of Device1 */
#define DEVICE1 0x01234567
struct MemoryMap {
uint32_t Reg1;
uint32_t Reg2;
};
template <uint32_t BASE_PTR>
class MyDriver {
public:
static uint32_t MyMethod() {
return ((struct MemoryMap*)BASE_PTR)->Reg1;
}
};
int main(int argc, char* argv[]) {
uint32_t reg = MyDriver<DEVICE1>::MyMethod();
return 0;
}
To avoid having to cast BASE_PTR all …
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