Buildroot and QEMU – the quickest receipe for your own Linux

I will show the fastest way of running your own-built Linux system in QEMU emulator. Did I say fastest? Let’s start then:

Where qemu_arm_versatile_defconfig is file & defconfig name from buildroot/configs directory. Next:

And menu similar to Linux kernel menuconfig shows up. Since we preconfigured it with the defconfig file, there is almost nothing to change here. Be sure to have all tools from Build options —> Commands menu installed in your host system.

In Build options check Enable compiler cache which will save compiler output files and make consequent compilations faster. It is not necessary though.

Now type this and get some coffee:

We have now the time to chat a bit. So, what we have just done is we run a massive process of downloading core packages and compiling them into toolchain, kernel and root filesystem that will became our own, small Linux OS. Ever heard that making Linux for embedded devices is hard? Well, it is. But we have taken three huge shortcuts.

First, by using Buildroot which is a big set of Makefiles that configures and compiles GCC, C library and whole OS ecosystem (BusyBox). What it produces in the end are the Linux kernel and the image of root filesystem.

Second shortcut is configuring Buildroot with qemu_arm_versatile_defconfig. There is nothing to change within the kernel thanks to this. This configuration file along with buildroot/board/qemu/arm-versatile/linux-3.10.config tells Buildroot to set kernel configuration to suit ARM Versatile boards template. This is one of the development platforms supported both by Linux and QEMU out of the box.

The last one is the use of QEMU. Because of that, we do not have to configure any bootloader (like U-Boot for instance). All we need to do is to run one command right after the compilation ends:

This was taken from buildroot/board/qemu/arm-versatile/readme.txt.

And there it is!

As in every shortcut there is not much to understand here. Please go further:

13. September 2013 by resset
Categories: Software | Tags: , , , , , , , , , | Leave a comment

How to install binwalk on Slackware (updated)

Update-even-more: Binwalk has just moved to GitHub.

Update: Second half of this tutorial refers to the binwalk version 1.2.1 only. It appears that with 1.2.2 release, problem with has been resolved. Diff here.

Firstly, a few dependencies.

There is a package “file” in Slackware but it doesn’t have it’s Python bindings installed. You need to download appropriate source file from here: Choose version that you have in your system. In my case it is 5.14.

# tar xzf file-5.14.tar.gz
# cd file-5.14/python
# python install

At this point you should run something like this without getting an exception:

# python
Python 2.7.5 (default, May 29 2013, 02:28:51)
[GCC 4.8.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import magic

Next, you may want to get matplotlib working. This is not required to and if you don’t want it you can fall back to regular binwalk install procedure (docs/README in binwalk sources) and quit reading this text. From now on, I assume you want to have fancy plotting option in your binwalk.

There is a bunch of packages to install. My preferred way to do this is by getting them from SlackBuilds. You can also use sbopkg tool, to speed up whole process. Install following packages in order: pysetuptools, six, python_dateutil, pytz, numpy and matplotlib.

Before we proceed there is a test to perform. Switch to non-root user and type:

$ python
Python 2.7.5 (default, May 29 2013, 02:28:51)
[GCC 4.8.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import matplotlib.pyplot

If you don’t get anything more serious than some fontconfig warnings, It’s OK to proceed.

Get binwalk: In my case current version is 1.2.1. Then, type:

# tar xzf binwalk-1.2.1.tar.gz
# cd binwalk-1.2.1/src

Now it’s tricky part. You want to have your binwalk installed globally since this is how setup script works, but installer (matplotlib.pyplot, actually) needs X server and you don’t have it in root’s python session. Because you verified that matplotlib.pyplot works on non-root user, where one usually runs software from, you can make little ugly hack to binwalk’s file. Let’s change the way how installer checks if matplotlib is present. This is a diff of original and modified file in patch format:

By changing method of plotting (to textual) you bypass the need for X server and installation runs smoothly. And app should work great too.

This is it, enjoy your binwalk:)

You may get a warning each time you run binwalk:

Warning: New continuation level 2 is more than one larger than current level 0

If so, update signatures (as root):

# binwalk -u

P.S. 2

Be sure to check for recommendations for other handy tools.

P.S. 3 (new)

Version 1.2.2 installs flawlessly.

05. August 2013 by resset
Categories: Software | Tags: , , | Leave a comment


Recently I made a small demo:

This is application running in ChibiOS/RT RTOS with addition of µGFX framework. It mimics screen unlocker known from Andriod smartphones. It was tested on Embest DM-STF4BB board with DM-LCD35RT LCD display, but should run on any other supported by µGFX. It works properly in ChibiOS/RT simulator also. For details how to run it there, please visit simulator introduction (link is dead, I’ll update this once it appears somewhere).

It allows to configure number of columns and rows you want to have, colors of the “rings” and few other options. The distance between rings is calculated automatically based on screen size and number of columns and rows. There are two functions to handle unlocker. displayUnlockerSetup() is used to draw and save unlock sequence. displayUnlocker() simply displays unlocker and exits if user drew proper pattern, either set by setup function or hardcoded. There is no persistence mechanism to store patterns.

The code is available at GitHub:

13. July 2013 by resset
Categories: Electronics, Hardware, Software | Tags: , , , , , | Leave a comment

Kate debugs in hardware

Or how to debug embedded devices with Kate editor, GCC toolchain, OpenOCD and JTAG. Or, how to replace Eclipse in embedded developer’s work.

I do most of my work with open source software, including this running on PC desktop. Few years ago my environment of choice became KDE (KDE SC nowadays). One of areas in which this choice (not ideal) shows its superiority over other desktops is multitude of accompanying applications. And the most useful for me are text editors. This backyard is dominated by indissoluble duo: KWrite and Kate. As it appears, these tools (more precisely, Kate – as it is “bigger brother”) can be used to do much more than editing.

So if you sit with KDE and some embedded stuff in front of your eyes why not give Kate a try? Curiously enough, it took me a while to hit on this idea;)

I assume that you:

  • have working GCC toolchain,
  • know how to use GDB (most preferably),
  • have proper Makefile(s), sources, linker scripts, vectors tables etc.,
  • know how to configure and use OpenOCD,
  • have hardware to play with (hardware debugger and target).

Kate setup

Start with regular Kate setup. Make new session, choose directory for it and import some source files – let us have something to play with. After that enable two plugins that Kate comes with: “Build Plugin” and “GDB”.

Kate Plugin Manager

Kate Plugin Manager

First one can execute “make” inside project directory, second gives actual ability to debug. Both of them extend interface of Kate a bit. This is how my editor looks now:

Kate main window

Kate main window

At top toolbar area appeared a bunch of unsurprisingly familiar buttons. I had to manually add first one (“Start debugging”). At the bottom there are two new activators: “Debug View” and “Build Output”. Open the first one and go to “Settings” tab, then click “Advanced Settings”.

GDB advanced settings dialog

GDB advanced settings dialog

This is where your desired setup may start to diverge from mine, but general guidelines should be the same for any case. In “GDB command” field put GDB executable name. Full path here is preferred, I didn’t manage to make it work relying on PATH. From select choose “Remote TCP”, set “localhost” as a host and “3333″ as a port that GDB will connect to. OpenOCD usually binds there. In “Custom Startup Commands” type all instructions that GDB have to execute before start debugging. This is important step, as Kate doesn’t know anything about debug server and your target. Every initialization step you have to undertake should go here or to OpenOCD scripts. Most common are loading binary to flash, remapping memory, setting clocks. To program flash you can use either GDB commands (if they work) or pass OpenOCD instructions as argument of “monitor” (or shortly: “mon”) command – as I do. Note last line of my input: I make GDB automatically break on “main” function.

GDB plugin settings

GDB plugin settings

Back to Settings tab, set path to executable file (usually in ELF format). If you set working directory, executable can be just a file name. The nice thing about Kate GDB plugin is that apart from controlling GDB it gives you its command prompt (GDB output tab). To keep focus on GDB console, select “Keep focus”. If your setup handles IO redirection properly, you should be able to control it in tab “IO”, which appears after checking “Redirect IO”. Mine doesn’t, so I did not test it. I saved this setup under “openocd” name; use whichever you like. Configurations are easily selectable in “Debug > Targets” top menu.

Build settings tab

Build settings tab

Next, configure build add-on settings. Hit “Build Output” activator at the bottom and select “Target Settings” tab. Fill in working directory, and next three inputs. I chose “Build” command to run both clean and make so the “Quick compile” executes only make and “Build” rebuilds entire project. Again, you can save this configuration under arbitrary name and load it later in “Build > Targets”. Build plugin doesn’t have its own toolbar so commands will be available in “Build” top menu.

Let’s run it!

Having this done we can move into action. Build your project using menu “Build > Build”. Then go to “Terminal” activator and type OpenOCD startup command. This activator shows up after enabling “Terminal tool view” plugin.

For my target I execute:


Kate terminal window

Kate terminal window

Click “Start Debugging” button. GDB Output tab should appear:

GDB console

GDB console

This is just a GDB console. Debugger stopped at “main” function as we told it to do. You can type “c” (continue) directly in highlighted input box, or hit “Continue” button from toolbar. Before doing that set cursor in editor to certain place in main() and make there breakpoint with “Toggle breakpoint” button.

Breakpoint inserted

Breakpoint inserted

Breakpoint line gets light red background. Inserting breakpoints is possible only when program is not being run.

Local variables view

Local variables view

Toggling activator to the right of main window, we get local variables preview.

To sum up

There are few more options that both described plugins provide, but most of “the meat” ends here. This is no equivalent to Eclipse-based toolchain setup (not to mention others), but makes nice distinction (faster! not Java! …and not Java!). And also gives very good quality of text editing, something what KatePart is known of. There is even vi-like mode:) Should you happen to consider improving current state of GDB plugin, maybe to push it more towards embeded world or to contribute to Kate itself – do not hesitate, it’s authors will welcome your efforts warm. So do I!

23. February 2013 by resset
Categories: Electronics, Software | Tags: , , , , , , , , , , | Leave a comment

Canny edge detector

I uploaded one of my student projects to GitHub: Canny algrithm implementation. This is popular method of finding edges in the image invented in 80′s: What you will find here is extremely naive approach, possibly with bugs and certainly not written with memory consumption issues in mind. But that’s just student project, it served well for its purpose:) Make sure to see README:

Below there is an exmple of each step of algorithm being performed:

Original image

Original image

Luminance extracted

Luminance extracted

Gaussian blur

Gaussian blur

Edge magnitude map

Edge magnitude map

Gradient direction map

Gradient direction map

Pixel suppresion result

Pixel suppresion result

After hysteresis thresholding - final image

After hysteresis thresholding – final image

24. December 2012 by resset
Categories: Software | Tags: , , , , | Leave a comment

Benefit of Cortex-M4F

Embedded systems gurus always repeated: don’t use floating-point numbers in your firmware! But what if you have processor with a FPU? Well, then you simply can. Do not forget, however, to carefully look at your disassembly file, as always.

So this is what we get with GCC 4.6.2 on Cortex-M3:

float a = 0.123123f;
 8000350:	4b21      	ldr	r3, [pc, #132]	; (80003d8 <main+0xd8>)
 8000352:	617b      	str	r3, [r7, #20]
	float b = 0.123123f;
 8000354:	4b20      	ldr	r3, [pc, #128]	; (80003d8 <main+0xd8>)
 8000356:	613b      	str	r3, [r7, #16]
	float c = 0.0f;
 8000358:	4b20      	ldr	r3, [pc, #128]	; (80003dc <main+0xdc>)
 800035a:	60fb      	str	r3, [r7, #12]
	c = a * b;
 800035c:	6978      	ldr	r0, [r7, #20]
 800035e:	6939      	ldr	r1, [r7, #16]
 8000360:	f000 f8d6 	bl	8000510 <__aeabi_fmul>
 8000364:	4603      	mov	r3, r0
 8000366:	60fb      	str	r3, [r7, #12]
	b = c;
 8000368:	68fb      	ldr	r3, [r7, #12]
 800036a:	613b      	str	r3, [r7, #16]


08000510 <__aeabi_fmul>:
 8000510:	f04f 0cff 	mov.w	ip, #255	; 0xff
 8000514:	ea1c 52d0 	ands.w	r2, ip, r0, lsr #23
 8000518:	bf1e      	ittt	ne
 800051a:	ea1c 53d1 	andsne.w	r3, ip, r1, lsr #23
 800051e:	ea92 0f0c 	teqne	r2, ip
 8000522:	ea93 0f0c 	teqne	r3, ip
 8000526:	d06f      	beq.n	8000608 <__aeabi_fmul+0xf8>
 8000528:	441a      	add	r2, r3
 800052a:	ea80 0c01 	eor.w	ip, r0, r1
 800052e:	0240      	lsls	r0, r0, #9
 8000530:	bf18      	it	ne
 8000532:	ea5f 2141 	movsne.w	r1, r1, lsl #9
 8000536:	d01e      	beq.n	8000576 <__aeabi_fmul+0x66>
 8000538:	f04f 6300 	mov.w	r3, #134217728	; 0x8000000
 800053c:	ea43 1050 	orr.w	r0, r3, r0, lsr #5
 8000540:	ea43 1151 	orr.w	r1, r3, r1, lsr #5
 8000544:	fba0 3101 	umull	r3, r1, r0, r1
 8000548:	f00c 4000 	and.w	r0, ip, #2147483648	; 0x80000000
 800054c:	f5b1 0f00 	cmp.w	r1, #8388608	; 0x800000
 8000550:	bf3e      	ittt	cc
 8000552:	0049      	lslcc	r1, r1, #1
 8000554:	ea41 71d3 	orrcc.w	r1, r1, r3, lsr #31
 8000558:	005b      	lslcc	r3, r3, #1
 800055a:	ea40 0001 	orr.w	r0, r0, r1
 800055e:	f162 027f 	sbc.w	r2, r2, #127	; 0x7f
 8000562:	2afd      	cmp	r2, #253	; 0xfd
 8000564:	d81d      	bhi.n	80005a2 <__aeabi_fmul+0x92>
 8000566:	f1b3 4f00 	cmp.w	r3, #2147483648	; 0x80000000
 800056a:	eb40 50c2 	adc.w	r0, r0, r2, lsl #23
 800056e:	bf08      	it	eq
 8000570:	f020 0001 	biceq.w	r0, r0, #1
 8000574:	4770      	bx	lr
 8000576:	f090 0f00 	teq	r0, #0
 800057a:	f00c 4c00 	and.w	ip, ip, #2147483648	; 0x80000000
 800057e:	bf08      	it	eq
 8000580:	0249      	lsleq	r1, r1, #9
 8000582:	ea4c 2050 	orr.w	r0, ip, r0, lsr #9
 8000586:	ea40 2051 	orr.w	r0, r0, r1, lsr #9
 800058a:	3a7f      	subs	r2, #127	; 0x7f
 800058c:	bfc2      	ittt	gt
 800058e:	f1d2 03ff 	rsbsgt	r3, r2, #255	; 0xff
 8000592:	ea40 50c2 	orrgt.w	r0, r0, r2, lsl #23
 8000596:	4770      	bxgt	lr
 8000598:	f440 0000 	orr.w	r0, r0, #8388608	; 0x800000
 800059c:	f04f 0300 	mov.w	r3, #0
 80005a0:	3a01      	subs	r2, #1
 80005a2:	dc5d      	bgt.n	8000660 <__aeabi_fmul+0x150>
 80005a4:	f112 0f19 	cmn.w	r2, #25
 80005a8:	bfdc      	itt	le
 80005aa:	f000 4000 	andle.w	r0, r0, #2147483648	; 0x80000000
 80005ae:	4770      	bxle	lr
 80005b0:	f1c2 0200 	rsb	r2, r2, #0
 80005b4:	0041      	lsls	r1, r0, #1
 80005b6:	fa21 f102 	lsr.w	r1, r1, r2
 80005ba:	f1c2 0220 	rsb	r2, r2, #32
 80005be:	fa00 fc02 	lsl.w	ip, r0, r2
 80005c2:	ea5f 0031 	movs.w	r0, r1, rrx
 80005c6:	f140 0000 	adc.w	r0, r0, #0
 80005ca:	ea53 034c 	orrs.w	r3, r3, ip, lsl #1
 80005ce:	bf08      	it	eq
 80005d0:	ea20 70dc 	biceq.w	r0, r0, ip, lsr #31
 80005d4:	4770      	bx	lr
 80005d6:	f092 0f00 	teq	r2, #0
 80005da:	f000 4c00 	and.w	ip, r0, #2147483648	; 0x80000000
 80005de:	bf02      	ittt	eq
 80005e0:	0040      	lsleq	r0, r0, #1
 80005e2:	f410 0f00 	tsteq.w	r0, #8388608	; 0x800000
 80005e6:	3a01      	subeq	r2, #1
 80005e8:	d0f9      	beq.n	80005de <__aeabi_fmul+0xce>
 80005ea:	ea40 000c 	orr.w	r0, r0, ip
 80005ee:	f093 0f00 	teq	r3, #0
 80005f2:	f001 4c00 	and.w	ip, r1, #2147483648	; 0x80000000
 80005f6:	bf02      	ittt	eq
 80005f8:	0049      	lsleq	r1, r1, #1
 80005fa:	f411 0f00 	tsteq.w	r1, #8388608	; 0x800000
 80005fe:	3b01      	subeq	r3, #1
 8000600:	d0f9      	beq.n	80005f6 <__aeabi_fmul+0xe6>
 8000602:	ea41 010c 	orr.w	r1, r1, ip
 8000606:	e78f      	b.n	8000528 <__aeabi_fmul+0x18>
 8000608:	ea0c 53d1 	and.w	r3, ip, r1, lsr #23
 800060c:	ea92 0f0c 	teq	r2, ip
 8000610:	bf18      	it	ne
 8000612:	ea93 0f0c 	teqne	r3, ip
 8000616:	d00a      	beq.n	800062e <__aeabi_fmul+0x11e>
 8000618:	f030 4c00 	bics.w	ip, r0, #2147483648	; 0x80000000
 800061c:	bf18      	it	ne
 800061e:	f031 4c00 	bicsne.w	ip, r1, #2147483648	; 0x80000000
 8000622:	d1d8      	bne.n	80005d6 <__aeabi_fmul+0xc6>
 8000624:	ea80 0001 	eor.w	r0, r0, r1
 8000628:	f000 4000 	and.w	r0, r0, #2147483648	; 0x80000000
 800062c:	4770      	bx	lr
 800062e:	f090 0f00 	teq	r0, #0
 8000632:	bf17      	itett	ne
 8000634:	f090 4f00 	teqne	r0, #2147483648	; 0x80000000
 8000638:	4608      	moveq	r0, r1
 800063a:	f091 0f00 	teqne	r1, #0
 800063e:	f091 4f00 	teqne	r1, #2147483648	; 0x80000000
 8000642:	d014      	beq.n	800066e <__aeabi_fmul+0x15e>
 8000644:	ea92 0f0c 	teq	r2, ip
 8000648:	d101      	bne.n	800064e <__aeabi_fmul+0x13e>
 800064a:	0242      	lsls	r2, r0, #9
 800064c:	d10f      	bne.n	800066e <__aeabi_fmul+0x15e>
 800064e:	ea93 0f0c 	teq	r3, ip
 8000652:	d103      	bne.n	800065c <__aeabi_fmul+0x14c>
 8000654:	024b      	lsls	r3, r1, #9
 8000656:	bf18      	it	ne
 8000658:	4608      	movne	r0, r1
 800065a:	d108      	bne.n	800066e <__aeabi_fmul+0x15e>
 800065c:	ea80 0001 	eor.w	r0, r0, r1
 8000660:	f000 4000 	and.w	r0, r0, #2147483648	; 0x80000000
 8000664:	f040 40fe 	orr.w	r0, r0, #2130706432	; 0x7f000000
 8000668:	f440 0000 	orr.w	r0, r0, #8388608	; 0x800000
 800066c:	4770      	bx	lr
 800066e:	f040 40fe 	orr.w	r0, r0, #2130706432	; 0x7f000000
 8000672:	f440 0040 	orr.w	r0, r0, #12582912	; 0xc00000
 8000676:	4770      	bx	lr

And this is output from the same GCC version on Cortex-M4F (compiled with flags -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 -ffast-math -fsingle-precision-constant):

float a = 0.123123f;
 8000410:	4b3c      	ldr	r3, [pc, #240]	; (8000504 )
 8000412:	617b      	str	r3, [r7, #20]
	float b = 0.123123f;
 8000414:	4b3b      	ldr	r3, [pc, #236]	; (8000504 )
 8000416:	613b      	str	r3, [r7, #16]
	float c = 0.0f;
 8000418:	4b3b      	ldr	r3, [pc, #236]	; (8000508 )
 800041a:	60fb      	str	r3, [r7, #12]
	c = a * b;
 800041c:	ed97 7a05 	vldr	s14, [r7, #20]
 8000420:	edd7 7a04 	vldr	s15, [r7, #16]
 8000424:	ee67 7a27 	vmul.f32	s15, s14, s15
 8000428:	edc7 7a03 	vstr	s15, [r7, #12]
	b = c;
 800042c:	68fb      	ldr	r3, [r7, #12]
 800042e:	613b      	str	r3, [r7, #16]

This is the difference, isn’t it?

08. July 2012 by resset
Categories: Electronics, Software | Tags: , , , | Leave a comment

VMware Workstation 8.0.2 on Linux 3.2.x

There is a great aricle (and blog) on solving problems with running VMware on Linux hosts: What is not said there is that sometimes you are unable even to install Workstation itself. The cause is that installer tries to build modules and it fails to do this, so the installation is reverted and you end up with nothing. The cure, which solved the case for me were following parameters:

# ./VMware-Workstation-Full-8.0.2-591240.x86_64.bundle --console --required --ignore-errors

Thanks to the –ignore-errors, after seeing few ugly Python tracebacks we finally get Installation was successful message. Now just run the patch:

# ./

…and VMware is all yours:)

16. April 2012 by resset
Categories: Software | Tags: , , | Leave a comment

Setting up a locale in PostgreSQL on Linux

After installation of fresh copy of PostgreSQL database server it is often required to configure proper localization settings. This helps to avoid messages like this:

ERROR: invalid locale name en_GB.utf8

where en_GB.utf8 is setting you want to have. In order to create a database with custom locale there are few steps one has to follow.

The first is to enable all locales you might want to use in PostgreSQL in your system config. On Debian, edit file /etc/locale.gen and uncomment lines with your locales names. In my case it looks like this:

# pl_PL ISO-8859-2
pl_PL.UTF-8 UTF-8
# ps_AF UTF-8

Then run command locale-gen which will generate system localization files.

# locale-gen
Generating locales (this might take a while)...
en_US.UTF-8... done
pl_PL.UTF-8... done
Generation complete.

I have two locales enabled: en_US.UTF-8 and pl_PL.UTF-8. Both of them should be available in PostgreSQL. To check that, switch user to postgres and run SQL console, psql:

# su - postgres
$ psql
psql (8.4.9)
Type "help" for help.


Create user (if you haven’t done this yet):

postgres=# CREATE ROLE myuser WITH PASSWORD 'secret' LOGIN;

Then create database with some extra parameters:

postgres=# CREATE DATABASE mydb WITH OWNER myuser ENCODING 'UTF8' LC_COLLATE 'pl_PL.utf8' LC_CTYPE 'pl_PL.utf8' TEMPLATE template0;

Most of this is self-explanatory. Purposes of all parameters are explained in the documentation: CREATE DATABASE. Note, that there is template0 database used as a template. More on this you will find in the manual: Template Databases.

Note: above example was successfully tested also on PostgreSQL 9.1.2.

08. January 2012 by resset
Categories: Software | Tags: , , , | Leave a comment

OpenOCD + Actel (Microsemi) CoreMP7

In my engineer degree work I used CoreMP7-enabled ProASIC3 Development Kit (part number M7A3P-DEV-KIT-SCS). In a time it was launched by Actel (acquired by Microsemi) it was one of the first attempts of creating a SoPC with soft ARM core available for wide market without royalties. This particular kit has M7A3P1000 chip with 484 balls, 1M system gates and can drive internal PLL up to 350 MHz, so it’s pretty powerful. There is 1 MB of on-board RAM and 16 MB of Intel FLASH.

ARM7TDMI-S processor itself is available as a compiled and pre-placed component that can be put into user system design in SmartDesign tool (part of Libero environment). Although one cannot simulate core directly due to the lack of HDL source files, there is a BFM script compiler which produces HDL testbenches simulating transfers over AHB system bus. User writes BFM (TCL-like) scripts as if they were processor read and write operations.

The board provides several ways of programming the device. FPGA configuration is loaded with on-board FlashPro3 programmer. The same tool can be used to program and debug software written for ARM processor via SoftConsole IDE (which is modified Eclipse software). Microsemi’s FlashPro3 debugger has serious limitation, however: it can only debug code running in RAM. It can program FLASH memory using additional application (cliarm.exe console) and on this its functionality ends. Producer didn’t left programmer without choice, there is additional JTAG header on board. It is called RV (RealView) header and can be connected with 20-wire (2×10) flat cable to regular JTAG programmer. This was the reason I installed and configured fresh Eclipse with CodeSourcery G++ Lite (now Mentor Graphics) version 2011.03-42 with GCC 4.5.2 and OpenOCD in version 0.4.0 (2010-02-22-19:05). Maybe in some further post I will discuss how to set up this environment, now let’s look how to connect a programmer to the ARM core.

I use device based on FT2232 (-C, -D, -L) chip, it is similar to Amontec JAGkey. This piece of hardware was designed by Freddie Chopin. It is has a standard JTAG dual-row pin header which easily connects with P3 connector on board:

M7A3P-DEV-KIT-SCS JTAG header schematics

M7A3P-DEV-KIT-SCS JTAG header schematics

SmartDesign CoreMP7Bridge

SmartDesign CoreMP7Bridge

The tricky part is how to connect the header to ARM processor. On the core side there are following connections:

Note, that UJTAG group refers to the ports that have predefined physical design constraints – they are automatically connected in Designer I/O Attribute Editor. They serve as a JTAG connected to FlashPro3.

As you can see ports in RV_ICE_If group are not one-to-one compatible with pins on board. What you have to do is to make a HDL wrapper that will sort these pins and do some other actions to make things work. In this step extremely helpful was sample project distributed with board. Its sources are present on a CD or in ZIP downloaded from Actel’s website, in folder Design/. To get that idea look at file Hardware/Source/socTop.v. There is also an example on how to connect memories to CoreMemCtrl module.

Finally, I had to write OpenOCD configuration scripts. Traditionally, they are split in two: one referring to CPU-specific settings and second with settings related to board. Unlike in hard processor cores in CoreMP7 you are the one who designs memory map, so most probably both of these files must be altered before use. Be sure to read the comments!


If you read this you probably already know there’s not much information about designs in Actel/Microsemi devices in the Internet. Producer gives excellent documentation and examples, but that’s all. I am aware that my article hasn’t covered topic even in a small part. This FPGA/ARM7 board is also quite ancient device (odd, isn’t it? 2007 if I recall well…) and I have experience only with this specific one. But it finally worked, so feel free to encourage me to write more:-)

13. December 2011 by resset
Categories: Electronics, Hardware, Software | Tags: , , , , | Leave a comment

Preserving /home directory on LVM while switching distros

I have been using Slackware since I remember. Well, it wasn’t that long ago but  it was one of the first distros I tried to use. It works (like a charm, I can’t deny) on my laptop, PC, VMs and in few other places. Times changed and now I decided to switch to other distro I know and like which is Debian. The question is, how to do this and not to loose any data in /home directory?

On virtual machine with Slackware I have four partitions:

/dev/sda1 – / ext4 (root directory)
/dev/sda2 – swap
/dev/sda3 – LVM PV
/dev/sda4 – LVM PV

As numbers say (and I say), all of them are primary.

Two PVs, sda3 and sda4 are merged into one VG named “user_data” and on this there is one LV named “home” containing /home directory with ext4 filesystem. I know this design is a bit weird but on this machine I used to play with LVM (adding, removing, resizing and more) and this is what has left. What I want to do is to throw away everything except /home directory. The final, satisfactory result will be fresh Debian installation with the same /home content. There is not much to do with partition design in my case, so I won’t be doing strange joining nor splitting.

So this is what to do if you want to save existing LVM partitions while installing Debian.

Start normal installation. Go through first steps, then in “Partition disks” window select manual partitioning method. Installer should properly recognize existence of LVM volumes. There should be two lists of devices on the screen, one starting with “LVM” referring to VG and one entitled “SCSI1″ which is hard disk (virtual in my case). In both there are sublists of devices.

Under “SCSI1″ there are all physical partitions. Since we do not want to change PVs we are interested only in sda1 (#1) for root and sda2 (#2) for swap. In “Partition settings” displayed after selecting #1 choose filesystem type you  want in “Use as”, set mount point to “/” and agree on formatting partition. Be sure that bootable flag is set and that’s it. Swap (#2) configuration is straightforward as installer should detect it automatically.

Under “LVM” there are listed all existing LVs.  In our example there is only one and we want it to be /home. What we need to do is to select it and setup as a normal partition. Extremely important is to not format it. Make sure the chosen option says “no, keep existing data”.

After that just select “Finish partitioning and write changes to disk” then confirm formatting of partitions #1 and #2. Continue normal installation and  after reboot we have what we wanted: /dev/mapper/user_data-home device mounted to /home directory with all data already there.

21. October 2011 by resset
Categories: Software | Tags: , , | Leave a comment

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