Processors Category - Page 1174 of 1176 - CNX Software

September 5, 2010December 11, 2020 by Jean-Luc Aufranc (CNXSoft) - No Comments

ViewSonic Android Tablet: ViewPad 7

Lots of Android Tablet were shown at IFA 2010 in Berlin. The most hyped was Samsung Galaxy Tab. Charbax has lot of videos about different devices. Among them, ViewSonic Viewpad 7 seems to be worth looking at with Android 2.2, #G, Wifi, video calling, capacitive touch screen and a retail price that should be 399 Euros. It actually seems to be doing all what the pricey Samsung tablet is doing (except lower camcorder resolution). On the hardware side, it is most likely using Qualcomm MSM7227 (ARM11). Jean-Luc Aufranc (CNXSoft)Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011. www.cnx-software.com

August 29, 2010November 25, 2010 by Jean-Luc Aufranc (CNXSoft) - No Comments

Digital Signage: Implementing a smooth scrolling text

Many digital signage hardware feature scroll text. However, in many cases the scrolling text is either not smooth, sometimes teared or very slow. It may depends on the performance of the hardware used but also on the implementation of the software. Once easy way to implemented scrolling text is just to redraw the text again and again at different position. However, this is very slow and yields poor results unless maybe you have a Truetype accelerator or similar hardware font accelerator. The next step is then to convert the text into pixmaps. This can either be done in the digital signage manager software (Windows PC/MAC or Linux based) or the digital signage player. Doing so in the latter makes it much more flexible. So you may create 2 pixmaps whose width and length match the region to be displayed, you write the text on those 2 pixmaps, then simply move […]

August 24, 2010 by Jean-Luc Aufranc (CNXSoft) - 1 Comment

Android Tablet Review: Augen Gentouch 2

Soldierknowsbest reviewed the Augen Gentouch 2 (same as Augen Gentouch 78 ??), one of the first Android tablet available (Cost around 150 USD). Basically, his advice is to avoid it, the device is terrible: poor touch screen (resistive), no multitouch, navigation requires to use external buttons, Android Market not working, some dodgy battery usage… On the hardware side, Augen Gentouch uses Telechips 8902 @ 600 Mhz, 256MB DDR2, 2GB Internal Storage, Wifi etc… Jean-Luc Aufranc (CNXSoft)Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011. www.cnx-software.com

August 14, 2010October 6, 2019 by Jean-Luc Aufranc (CNXSoft) - No Comments

Media Player based on SMP8653 – Magic Box HDP500

Magic Box HDP500 manufactured by gmini (apparently a Russian company) is a new media player featuring the 500-Mhz SMP8653 chipset from Sigma Designs. It does not use Android OS yet, and as far I know no company has yet released SMP8653 Android based products. Having said that, it comes with most of the connectivity you would expect from a decent set-top box: USB connector (device: USB storage,host: laptop/PC connection), Audio/Video Composite ouput, Component (YPbPr) output, HDMI and optical digital audio output and and Ethernet port. On the software side, it is a full featured 1080p media player, with video, music and picture galleries, Internet Radio, UPnP support… It could also be used as a NAS with the USB host connection to your PC. The missing features are: no support for digital TV (e.g. DVB-T, DMB-TH), no Wifi support, no web applications/web browser, no movie download (BT/Emule), no Real media video […]

July 28, 2010May 12, 2018 by Jean-Luc Aufranc (CNXSoft) - No Comments

Enabling swap in embedded systems

If your embedded system running Linux does not have enough memory, you can enable swap to get more memory. However if your platform does not have MMU (Memory Management Unit) as is the case for Sigma Designs EM8620 series, it won’t support swap, so forget it. If your platform does have MMU, as is the case for many newer platforms such as Sigma Designs SMP8630, SMP8640 and SMP8650 series, you can enable swap support. First you’ll have to make sure swap support is enabled in your kernel:

CONFIG_SWAP=y
CONFIG_SWAP_PREFETCH=y

1 2	CONFIG_SWAP=y CONFIG_SWAP_PREFETCH=y

and swapon/swapoff is enabled in busybox. So for example if you have an IDE harddisk with the second partition configured as swap. (Use fdisk to create a partition and mkswap /dev/hda2 to initialize the partition), you can enable the swap as follows:

swapon /dev/hda2

1	swapon /dev/hda2

If you get out-of-memory killer kernel error, you can change the “swapiness” to avoid oom-killer to kick in.

echo 0 &gt; /proc/sys/vm/mapped

1	echo 0 > /proc/sys/vm/mapped

[…]

July 18, 2010December 20, 2016 by Jean-Luc Aufranc (CNXSoft) - 9 Comments

How to do a framebuffer screenshot

I’ll explain how to do framebuffer screenshots on 16-bit and 32-bit framebuffer. For 16-bit this is fully based on http://docs.blackfin.uclinux.org/doku.php?id=framebuffer Capturing screenshots Whatever the bit-depth of your framebuffer, the first step is to capture the frambuffer raw data on the board:

cat /dev/fb0 > screen.raw

1	cat /dev/fb0 > screen.raw

Now the you need to take the raw image, and convert it to a standard image format. This step depends on what type of display is there Converting 16-bit Framebuffer screenshot (RGB565) into png To convert the raw rgb data extracted from /dev/fb0, use iraw2png perl script

#!/usr/bin/perl -w

$w = shift || 240;
$h = shift || 320;
$pixels = $w * $h;

open OUT, "|pnmtopng" or die "Can't pipe pnmtopng: $!\n";

printf OUT "P6%d %d\n255\n", $w, $h;

while ((read STDIN, $raw, 2) and $pixels--) {
   $short = unpack('S', $raw);
   print OUT pack("C3",
      ($short & 0xf800) >> 8,
      ($short & 0x7e0) >> 3,
      ($short & 0x1f) << 3);
}

close OUT;

#!/usr/bin/perl -w

$w = shift || 240;

$h = shift || 320;

$pixels = $w * $h;

open OUT, "|pnmtopng" or die "Can't pipe pnmtopng: $!\n";

printf OUT "P6%d %d\n255\n", $w, $h;

while ((read STDIN, $raw, 2) and $pixels--) {

$short = unpack('S', $raw);

print OUT pack("C3",

($short & 0xf800) >> 8,

($short & 0x7e0) >> 3,

($short & 0x1f) << 3);

}

close OUT;

To do the conversion, type the following command in the host:

./iraw2png 640 480 < screen.raw > screen.png

1	./iraw2png 640 480 < screen.raw > screen.png

where 640 and 480 are respectively the width and height of your framebuffer. This has been tried on a 16-bit framebuffer on EM8620 series. Converting 32-bit Framebuffer screenshot (ARGB, RGBA, BGRA…) into png The solution proposed here is not as neat as the blackfin’s solution for 16-bit framebuffer, […]

July 11, 2010November 24, 2019 by Jean-Luc Aufranc (CNXSoft) - No Comments

uClinux kernel panic: Stack overflow

If you’re using ucLinux, you may get kernel panic errors coming out of nowhere. There may be several reasons (buffer overflow, out of memory..), but the most common is stack overflow for the process or one of the threads. To increase the stack size of a flat binary you’ll need to adjust the LDFLAGS as follows:

LDFLAGS+=-Wl,-elf2flt="-s65536"

1	LDFLAGS+=-Wl,-elf2flt="-s65536"

This will set the stack size to 64KB. To change the stack size of a thread (e.g. 32KB below), you’ll need to set the stack size attribute:

pthread_attr_init(&attr);
err = pthread_attr_setstacksize(&attr, 32*1024);
if (err) {
    printf("pthread_attr_setstacksize returned non-zero: %s\n",
    strerror(errno));
}
err = pthread_create(&pthThread, &attr, thread, NULL);

pthread_attr_init(&attr);

err = pthread_attr_setstacksize(&attr, 32*1024);

if (err) {

printf("pthread_attr_setstacksize returned non-zero: %s\n",

strerror(errno));

}

err = pthread_create(&pthThread, &attr, thread, NULL);

How to detect which thread suffers from stack overflow? First, you can check your code for recursive function calls and local variables (especially arrays) both of which will be added at runtime to the stack to estimate what should be the stack size. So if you have large arrays you may use a pointer + a call to malloc instead. If this can not fix […]

June 26, 2010March 2, 2017 by Jean-Luc Aufranc (CNXSoft) - No Comments

EP9307 Thin Client with DirectVNC

One of my reader had issues running Thin-clients ENTC Encore-1000 based on EP9307 and wanted to update the firmware in his systems. So I’ll explain how to access Linux, Windows XP or any other operating systems using a thin client based on Cirrus Logic EP9307 hardware. This is for reference only, and the performance may not be suitable for your environment/setup. One PC (server) is needed to run VNC (Virtual Network Computing) server for each remote desktop (i.e. each thin client), then the thin client can run the software without hard disk by just using the network connection. This can be used for checking emails, browsing internet, office applications, etc.. All resource heavy tasks are done on the server side whose specifications may be chosen to match the applications requirements. I’ll explain how to use Linux, but Windows XP (or any other operating systems for that matter) could also be […]