Tag Archives: pandaboard

ARMv7a hardware is like minefield

I have a bunch of ARMv7a boards at home. They are from different years, have misc CPUs and GPUs. All I think that some of them suck for some reasons.

Pandaboard was great board when got released. Then Texas Instruments fired everyone involved so now it is crap. Sure, mainline kernel works fine but no audio/video decoding in hardware, no OpenGLES due to PowerVR stuff which no one cares about because it is proprietary.

Wandboard Quad. Cool, fast, 2GB of memory, SATA. And hardcoded XGA (1024×768) resolution which can not be changed. Awesome? Not so much when you connect it to FullHD monitor. And forget about community — they are mostly stuck on 3.0 and 3.10 kernels based on Freescale code drops. I should dig deeper when looked at i.mx6 hardware ;(

Looks like it is time to check other boards. Minnowboard Max probably — x86 will fully open drivers.

New project: Pandaboard based media player

I need an offline media player to play movies from hard drive. And I did not managed to find something interesting on a market. So decided to take a look into my electronics trashcan and dig some parts from it.

What did I found?

  • PandaBoard EA1
  • USB 3.0 to SATA adapter
  • 750GB 2.5″ SATA hard drive
  • 2xUSB PC bracket
  • 3.5A 5V power supply
  • u.FL to RP-SMA cable

Looks just fine for my needs. OMAP4430 ES2.0 cpu should be enough and with some libraries should decode everything I have. Just 1GB ram but hope to be enough, there is WiFi and Bluetooth on board with u.FL connector so I can get external RP-SMA antenna. HDMI with audio but no idea about CEC for remote control. And there are 4 USB ports (two at rear and two on pins) so internal hard drive is possible without any extra cables sticking outside.

OK, hard disk will be over USB 2.0 which is quite slow compared to SATA. But that’s all what is available on board. Otherwise I would have to buy new one.

Will have to find big enough plastic case to fit both boards and hard disk, cut some holes for power, HDMI and maybe also USB and RP-SMA antenna connector. Then solder J3 and J6 pins to get extra 2 USB ports, power and reset buttons and maybe even will do power LED.

Then connect USB3 -> SATA adapter into internal USB port, wire power cables to charge it directly from Pandaboard power plug (for when USB would not be enough) and get it running.

Have to check is there any good Android build for a board as this may give me more options than GNU/Linux distros with XBMC like apps. And have to solve remote control as well.

UPDATE: I booted Android 4.3.1 Jellybean (Linaro 13.10) on the board. It is so slow (with HW acceleration) that I am unable to use it. So project gets postponed to unknown date.

ARMology

When last time I was in Cambridge we had a discussion about ARM processors. Paweł used term “ARMology” then. And with recent announcement of Cortex-A12 cpu core I thought that it may be a good idea to write a blog post about it.

Please note that my knowledge of ARM processors started in 2003 so I can make mistakes in everything older. Tried to understand articles about old times but sometimes they do not keep one version of story.

Ancient times

ARM1 got released in 1985 as CPU add-on to BBC Micro manufactured by Acorn Computers Ltd. as result of few years of research work. They wanted to have new processor to replace ageing 6502 used in BBC Micro and Acorn Electron and none of existing ones did not fit their requirements. Note that it was not market product but rather development tool made available for selected users.

But it was ARM2 which landed in new computers — Acorn Archimedes (1987 year). Had multiply instructions added so new version of instruction set was created: ARMv2. Just 8MHz clock but remember that it was first computer with new CPU…

Then ARM3 came — with cache controller integrated and 25MHz clock. ISA was bumped to ARMv2a due to SWP instruction added. And it was released in another Acorn computer: A5000. This was also used in Acorn A4 which was first ARM powered laptop (but term “ARM Powered” was created few years later). I hope that one day I will be able to play with all those old machines…

There was also ARM250 processor with ARMv2a instruction set like in ARM3 but no cache controller. But it is worth mentioning as it can be seen as first SoC due to ARM, MEMC, VIDC, IOC chips integrated in one piece of silicon. This allowed to create budget versions of computers.

ARM Ltd.

In 1990 Acorn, Apple and VLSI co-founded Advanced RISC Machines Ltd. company which took over research and development of ARM processors. Their business model was simple: “we work on cpu cores and other companies pay us license costs to make chips”.

Their first cpu was ARM60 with new instruction set: ARMv3. It had 32bit address space (compared to 26bit in older versions), was endian agnostic (so both big and little endian was possible) and there were other improvements.

Please note lack of ARM4 and ARM5 processors. I heard some rumours about that but will not repeat them here as some of them just do not fit when compared against facts.

ARM610 was powering Apple Newton PDA and first Acorn RiscPC machines where it was replaced by ARM710 (still ARMv3 instruction set but ~30% faster).

First licensees

You can create new processor cores but someone has to buy them and manufacture… In 1992 GEC Plessey and Sharp licensed ARM technology, next year added Cirrus Logic and Texas Instruments, then AKM (Asahi Kasei Microsystems) and Samsung joined in 1994 and then others…

From that list I recognize only Cirrus Logic (used their crazy EP93xx family), TI and Samsung as vendors of processors ;D

Thumb

One of next cpu cores was ARM7TDMI (Thumb+Debug+Multiplier+ICE) which added new instruction set: Thumb.

The Thumb instructions were not only to improve code density, but also to bring the power of the ARM into cheaper devices which may primarily only have a 16 bit datapath on the circuit board (for 32 bit paths are costlier). When in Thumb mode, the processor executes Thumb instructions. While most of these instructions directly map onto normal ARM instructions, the space saving is by reducing the number of options and possibilities available — for example, conditional execution is lost, only branches can be conditional. Fewer registers can be directly accessed in many instructions, etc. However, given all of this, good Thumb code can perform extremely well in a 16 bit world (as each instruction is a 16 bit entity and can be loaded directly).

ARM7TDMI landed nearly everywhere – MP3 players, cell phones, microwaves and any place where microcontroller could be used. I heard that few years ago half of ARM Ltd. income was from license costs of this cpu core…

ARM7

But ARM7 did not ended at ARM7TDMI… There was ARM7EJ-S core which used ARMv5TE instruction set and also ARM720T and ARM740T with ARMv4T. You can run Linux on Cirrus Logic CLPS711x/EP721x/EP731x ones ;)

According to ARM Ltd. page about ARM7 the ARM7 family is the world’s most widely used 32-bit embedded processor family, with more than 170 silicon licensees and over 10 Billion units shipped since its introduction in 1994.

ARM8

I heard that ARM8 is one of those things you should not ask ARM Ltd. people about. Nothing strange when you look at history…

ARM810 processor made use of ARMv4 instruction set and had 72MHz clock. At same time DEC released StrongARM with 200MHz clock… 1996 was definitively year of StrongARM.

In 2004 I bought my first Linux/ARM powered device: Sharp Zaurus SL-5500.

ARM9

Ah ARM9… this was huge family of processor cores…

ARM moved from a von Neumann architecture (Princeton architecture) to a Harvard architecture with separate instruction and data buses (and caches), significantly increasing its potential speed.

There were two different instruction sets used in this family: ARMv4T and ARMv5TE. Also some kind of Java support was added in the latter one but who knows how to use it — ARM keeps details of Jazelle behind doors which can be open only with huge amount of money.

ARMv4T

Here we have ARM9TDMI, ARM920T, ARM922T, ARM925T and ARM940T cores. I mostly saw 920T one in far too many chips.

My collection includes:

  • ep93xx from Cirrus Logic (with their sick VFP unit)
  • omap1510 from Texas Instruments
  • s3c2410 from Samsung (note that some s3c2xxx processors are ARMv5T)

ARMv5T

Note: by ARMv5T I mean every cpu never mind which extensions it has built-in (Enhanced DSP, Jazelle etc).

I consider this one to be most popular one (probably after ARM7TDMI). Countless companies had own processors based on those cores (mostly on ARM926EJ-S one). You can get them even in QFP form so hand soldering is possible. CPU frequency goes over 1GHz with Kirkwood cores from Marvell.

In my collection I have:

  • at91sam9263 from Atmel
  • pxa255 from Intel
  • st88n15 from ST Microelectronics

Had also at91sam9m10, Kirkwood based Sheevaplug and ixp425 based NSLU2 but they found new home.

ARM10

Another quiet moment in ARM history. ARM1020E, ARM1022E, ARM1026EJ-S cores existed but did not looked popular.

UPDATE: Conexant uses ARM10 core in their next generation DSL CPE systems such as bridge/routers, wireless DSL routers and DSL VoIP IADs.

ARM11

Released in 2002 as four new cores: ARM1136J, ARM1156T2, ARM1176JZ and ARM11 MPCore. Several improvements over ARM9 family including optional VFP unit. New instruction set: ARMv6 (and ARMv6K extensions). There was also Thumb2 support in arm1156 core (but I do not know did someone made chips with it). arm1176 core got TrustZone support.

I have:

  • omap2430 from Texas Instruments
  • i.mx35 from Freescale

Currently most popular chip with this family is BCM2835 GPU which got arm1136 cpu core on die because there was some space left and none of Cortex-A processor core fit there.

Cortex

New family of processor cores was announced in 2004 with Cortex-M3 as first cpu. There are three branches:

  • Aplication
  • Realtime
  • Microcontroller

All of them (with exception of Cortex-M0 which is ARMv6) use new instruction sets: ARMv7 and Thumb-2 (some from R/M lines are Thumb-2 only). Several cpu modules were announced (some with newer cores):

  • NEON for SIMD operations
  • VFP3 and VFP4
  • Jazelle RCT (aka ThumbEE).
  • LPAE for more then 4GB ram support (Cortex A7/12/15)
  • virtualization support (A7/12/15)
  • big.LITTLE
  • TrustZone

I will not cover R/M lines as did not played with them.

Cortex-A8

Announced in 2006 single core ARMv7a processor core. Released in chips by Texas Instruments, Samsung, Allwinner, Apple, Freescale, Rockchip and probably few others.

Has higher clocks than ARM11 cores and achieves roughly twice the instructions executed per clock cycle due to dual-issue superscalar design.

So far collected:

  • am3358 from Texas Instruments
  • i.mx515 from Freescale
  • omap3530 from Texas Instruments

Cortex-A9

First multiple core design in Cortex family. Allows up to 4 cores in one processor. Announced in 2007. Looks like most of companies which had previous cores licensed also this one but there were also new vendors.

There are also single core Cortex-A9 processors on a market.

I have products based on omap4430 from Texas Instruments and Tegra3 from NVidia.

Cortex-A5

Announced around the end of 2009 (I remember discussion about something new from ARM with someone at ELC/E). Up to 4 cores, mostly for use in all designs where ARM9 and ARM11 cores were used. In other words new low-end cpu with modern instruction set.

Cortex-A15

The fastest (so far) core in ARMv7a part of Cortex family. Up to 4 cores. Announced in 2010 and expanded ARM line with several new things:

  • 40-bit LPAE which extends address range to 1TB (but 32-bit per process)
  • VFPv4
  • Hardware virtualization support
  • TrustZone security extensions

I have Chromebook with Exynos5250 cpu and have to admit that it is best device for ARM software development. Fast, portable and hackable.

Cortex-A7

Announced in 2011. Younger brother of Cortex-A15 design. Slower but eats much less power.

Cortex-A12

Announced in 2013 as modern replacement for Cortex-A9 designs. Has everything from Cortex-A15/A7 and is ~40% faster than Cortex-A9 at same clock frequency. No chips on a market yet.

big.LITTLE

That’s interesting part which was announced in 2011. It is not new core but combination of them. Vendor can mix Cortex-A7/12/15 cores to have kind of dual-multicore processor which runs different cores for different needs. For example normal operation on A7 to save energy but go up for A15 when more processing power is needed. And amount of cores in each of them does not even have to match.

It is also possible to make use of all cores all together which may result in 8-core ARM processor scheduling tasks on different cpu cores.

There are few implementations already: ARM TC2 testing platform, HiSilicon K3V3, Samsung Exynos 5 Octa and Renesas Mobile MP6530 were announced. They differ in amount of cores but all (except TC2) use the same amount of A7/A15 cores.

ARMv8

In 2011 ARM announced new 64-bit architecture called AArch64. There will be two cores: Cortex-A53 and Cortex-A57 and big.LITTLE combination will be possible as well.

Lot of things got changed here. VFP and NEON are parts of standard. Lot of work went into making sure that all designs will not be so fragmented like 32-bit architecture is.

I worked on AArch64 bootstrapping in OpenEmbedded build system and did also porting of several applications.

Hope to see hardware in 2014 with possibility to play with it to check how it will play compared to current systems.

Other designs

ARM Ltd. is not the only company which releases new cpu cores. That’s due to fact that there are few types of license you can buy. Most vendors just buy licence for existing core and make use of it in their designs. But some companies (Intel, Marvell, Qualcomm, Microsoft, Apple, Faraday and others) paid for ‘architectural license’ which allows to design own cores.

XScale

Probably oldest one was StrongARM made by DEC, later sold to Intel where it was used as a base for XScale family with ARMv5TEJ instruction set. Later IWMMXT got added in PXA27x line.

In 2006 Intel sold whole ARM line to Marvell which released newer processor lines and later moved to own designs.

There were few lines in this family:

  • Application Processors (with the prefix PXA).
  • I/O Processors (with the prefix IOP)
  • Network Processors (with the prefix IXP)
  • Control Plane Processors (with the prefix IXC).
  • Consumer Electronics Processors (with the prefix CE).

One day I will undust my Sharp Zaurus c760 just to check how recent kernels work on PXA255 ;D

Marvell

Their Feroceon/PJ1/PJ4 cores were independent ARMv5TE implementations. Feroceon was Marvell’s own ARM9 compatible CPU in Kirkwood and others, while PJ1 was based on that and replaced XScale in later PXA chips. PJ4 is the ARMv7 compatible version used in all modern Marvell designs, both the embedded and the PXA side.

Qualcomm

Company known mostly from wireless networks (GSM/CDMA/3G) released first ARM based processors in 2007. First ones were based on ARM11 core (ARMv6 instruction set) and in next year also ARMv7a were available. Their high-end designs (Scorpion and Krait) are similar to Cortex family but have different performance. Company also has Cortex-A5 and A7 in low-end products.

Nexus 4 uses Snapdragon S4 Pro and I also have S4 Plus based Snapdragon development board.

Faraday

Faraday Technology Corporation released own processors which used ARMv4 instruction set (ARMv5TE in newer cores). They were FA510, FA526, FA626 for v4 and FA606TE, FA626TE, FMP626TE and FA726TE for v5te. Note that FMP626TE is dual core!

They also have license for Cortex-A5 and A9 cores.

Project Denver

Quoting Wikipedia article about Project Denver:

Project Denver is an ARM architecture CPU being designed by Nvidia, targeted at personal computers, servers, and supercomputers. The CPU package will include an Nvidia GPU on-chip.

The existence of Project Denver was revealed at the 2011 Consumer Electronics Show. In a March 4, 2011 Q&A article CEO Jen-Hsun Huang revealed that Project Denver is a five year 64-bit ARM architecture CPU development on which hundreds of engineers had already worked for three and half years and which also has 32-bit ARM architecture backward compatibility.

The Project Denver CPU may internally translate the ARM instructions to an internal instruction set, using firmware in the CPU.

X-Gene

AppliedMicro announced that they will release AArch64 processors based on own cores.

Final note

If you spotted any mistakes please write in comments and I will do my best to fix them. If you have something interesting to add also please do a comment.

I used several sources to collect data for this post. Wikipedia articles helped me with details about Acorn products and ARM listings. ARM infocenter provided other information. Dates were taken from Wikipedia or ARM Company Milestones page. Ancient times part based on The ARM Family and The history of the ARM CPU articles. The history of the ARM architecture was interesting and helpful as well.

Please do not copy this article without providing author information. Took me quite long time to finish it.

Changelog

8 June evening

Thanks to notes from Arnd Bergmann I did some changes:

  • added ARM7, Marvell, Faraday, Project Denver, X-Gene sections
  • fixed Cortex-A5 to be up to 4 cores instead of single.
  • mentioned Conexant in ARM10 section.
  • improved Qualcomm section to mention which cores are original ARM ones, which are modified.

David Alan Gilbert mentioned that ARM1 was not freely available on a market. Added note about it.

I am running out of names for computers

Somewhere in 2010/11 I decided to clean up mess of naming machines at home and decided to go with character names from “Winnie the Pooh” books (Polish edition). Today I got new developer board and had to spend a moment to get a name for it.

So “klapouchy” (Eyeore) will be new name for DragonBoard. Maybe not best one but most of the names are already taken:

  • krzys (Christopher Robin) is my router (because Chris decides who can enter Hundred Acre Wood which is the name of my WiFi network)
  • puchatek (Winnie the Pooh) is main desktop
  • lumpek (Lumpy) is conference laptop (it was lucek before because it got Ubuntu Lucid as first system)
  • gofer (Gopher) is Efika MX Smartbook
  • krolik (Rabbit) is Samsung Chromebook
  • malenstwo (Roo) is Pandaboard (there were malenstwo-a1 and malenstwo-ea1 when I had two boards)
  • prosiaczek (Piglet) was MX53 Quickstart
  • kangurzyca (Kanga) is my wife laptop (she chosen the name)
  • sowa (Owl) is another router
  • tygrysek (Tigger) is my VPS (at beginning it was up/down/up/down all the time)

So most of the names from books are already taken. There are also Disney movies which adds few new ones (like Gopher and Lumpy) and cartoons (which I am not fan of). In worst case one day I will start re-using names or add names from other story.

What I used before? Desktop was “home” or “hrw”, Dell laptop (now “kangurzyca”) was “maluch” (small) due to 12″ size, “lumpek” was “lucek” due to Ubuntu Lucid installed and rest was named by hardware name (which is a default in OpenEmbedded).

How you are naming your machines?

What interest me in ARM world

When I published my last post about ARM boards there were many questions and suggestions with interesting devices. Thank You all for it.

But there were also suggestions about ARM9 or ARM11 based devices. So I decided that it is good time to write what interest me now in ARM world.

But first some inventory. I had/used/have several devices with ARM cpu:

  • StrongARM (armv4) one:

    • Sharp Zaurus SL-5500 (which took me to ARM world)
  • ARM920 (armv4t) ones:

    • Openmoko GTA01 bv3, bv4 (s3c2410)
    • EDB9301 (EP9301 cpu)
    • Sim-One (EP9307)
  • ARM926 (armv5te) ones:

    • Sharp Zaurus sl-5600 (pxa250)
    • Sharp Zaurus c760/sl-6000 (pxa255)
    • Sharp Zaurus sl-c3000 (pxa272)
    • Sheevaplug (kirkwood)
    • Atmel devboards (at91sam9263, at91sam9m10)
    • ST-Microelectronics/ST-Ericsson NDK-15, NHK-15 (st88n15)
    • Nokia 770 (omap1710)
    • Linksys NSLU2 (ixp425 iirc)
  • ARM1136 (armv6) ones:

    • Nokia N810 (omap2430)
    • Bug r1.0, r1.2 (i.mx31)
  • Cortex-A8 (armv7a) ones:

    • Beagleboard B7, B7, C3 (omap3430)
    • Nokia N900 (omap3430)
    • Nexus S (exynos3)
    • Genesi Efika MX Smartbook (i.mx51)
    • Freescale Quickstart (i.mx53)
  • Cortex-A9 (armv7a) ones:

    • Pandaboard EA1, A1 (omap4430)
    • Archos G9 80 (omap4430)

All of that during last 8 years. Most of my ARM live so far was around ARM926 based devices (some of them still can not be listed here) and I do not want to go there again. Kirkwood core was fastest one with 1.2GHz clock and 512MB of RAM it was really fast machine. I only missed Serial ATA in my Sheevaplug (rev 1.0) but even with hard drive on USB it was nice improvement.

Then I played a bit with ARM11 processors. Ok, they were faster than most of ARM9 cpus but I already had experience with Sheevaplug. And after few months first Cortex-a8 board landed on my desk — I got Beagleboard B7 from Bug labs as test platform for their new device. This was improvement!

I still remember my reaction when connected it to normal LCD monitor and saw it used at 720p resolution (1680×1050 was a bit hard for omap3). Moved to Nokia N900 few months later and found that fast cpu means nothing when paired with slow storage and not enough memory for system.

So today I prefer to not look below Cortex-A9 (or comparable cores like ones from Qualcomm or Marvell). Hope to play one day with Cortex-A5 (which should replace ARM926 one day) just to see how low-end armv7a cpu behave.

And wait for ARMv8 to hit market.

I am tired of Raspberry/Pi

Please people… stop asking me about Raspberry/Pi. I do not want it, do not plan to buy one (when they will be finally available for normal people) and for sure do not plan to support it.

Raspberry/Pi may look as interesting hardware to you but it does not have to mean same to others. Want to run desktop? 256MB of memory means really crippled one (last time I saw this amount of RAM in desktop computer right before opening it to add 512MB stick). Sure, for 25-35 USD it is proper range as memory is probably the most expensive part. Device may be good for using it in more embedded environment where GPIO/I²C/I²S/SPI/UART matter — expansion connector provides those signals.

But I would rather buy BeagleBone to play with peripherials connected to such pins. Someone may ask “why? it is more expensive”. Reason is simple — it is in production, already has expansions which adds things like video output, touchscreens. And it has ARMv7 cpu which allows me to run any ARM distribution available today — so Debian ‘armel/armhf’, Ubuntu, Fedora, OpenSUSE, Ångström (which is preinstalled with great IDE to play with device already) or anything other.

I do not need small device which can run XMBC or Quake — have private PandaBoard which can do that too and has few things more than Raspberry/Pi.

And I do not think that companies which do software should start working on <100USD hardware like article at Techblaze suggests.