Tag Archives: linux

USB Sucks Badly?

I bought new hub to use on my desk: 7 port USB 3.0 one with switchable ports. Connected to USB 3.0 port and problems started…

Base of my desktop is P67X-UD3-B3 mainboard from Gigabyte which I have chosen due to amount of USB ports on back (alternative was one of Z68 based mainboard which would give me HDMI/VGA/DVI ports for integrated graphics). But now it looks like it was not good choice.

I have those devices connected:

  • Microsoft Optical Mouse with Tilt Wheel
  • Microsoft Natural Ergonomic Keyboard 4000
  • Future Technology Devices International, Ltd FT232 USB-Serial
  • Logitech Webcam Pro 9000
  • NEC HighSpeed Hub integrated in my second monitor
  • Genesys Logic based 7-port USB 3.0 hub on my desk
  • Samsung ML-2160 Laser printer

But when I plug any of those USB 1.1 devices all I have is “Not enough bandwidth for new device state.” message from kernel. Faster devices are fine so I can connect pen drives, hard drives, phones or tablets. But forget about USB-Serial dongles or Yubikeys or BlueTooth…

Why’s that? Take a look at “lsusb -t” output:

/:  Bus 06.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 5000M
/:  Bus 05.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 480M
/:  Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 5000M
    |__ Port 1: Dev 6, If 0, Class=Hub, Driver=hub/4p, 5000M
        |__ Port 1: Dev 7, If 0, Class=Hub, Driver=hub/4p, 5000M
/:  Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 480M
    |__ Port 1: Dev 28, If 0, Class=Hub, Driver=hub/4p, 480M
        |__ Port 1: Dev 29, If 0, Class=Hub, Driver=hub/4p, 480M
            |__ Port 3: Dev 62, If 0, Class=Mass Storage, Driver=usb-storage, 480M
    |__ Port 2: Dev 54, If 0, Class=Printer, Driver=usblp, 480M
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M
    |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/8p, 480M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M
    |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/6p, 480M
        |__ Port 3: Dev 10, If 0, Class=Hub, Driver=hub/4p, 480M
            |__ Port 2: Dev 11, If 0, Class=Video, Driver=uvcvideo, 480M
            |__ Port 2: Dev 11, If 1, Class=Video, Driver=uvcvideo, 480M
            |__ Port 2: Dev 11, If 2, Class=Audio, Driver=snd-usb-audio, 480M
            |__ Port 2: Dev 11, If 3, Class=Audio, Driver=snd-usb-audio, 480M
            |__ Port 3: Dev 12, If 0, Class=Vendor Specific Class, Driver=ftdi_sio, 12M
        |__ Port 5: Dev 5, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M
        |__ Port 5: Dev 5, If 1, Class=Human Interface Device, Driver=usbhid, 1.5M
        |__ Port 6: Dev 6, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M

How many EHCI buses do you see? You may say two (as there are two ehci-pci entries) or you may say four (as there are four 480M buses). I would say that “not enough” is best answer.

I played with cables to move devices from 2nd bus to 1st one, moved printer from 3rd bus to 5th (which is two USB 3.0 connectors on top of computer’s case) and still not enough bandwidth for Yubikey or other USB 1.1 device. Note that all devices plugged into on-desk USB 3.0 hub lands on 3rd (1.1/2.0) or 4th (3.0) bus.

During next few days I will plug extra USB 2.0 controller to check will it improve situation after keyboard, mouse, monitor, webcam, ftdi move there.

UPDATE: turns out that USB 3.0 hub does not fully conform to specification. In the end I have added USB 2.0 hub (connected to 2.0 port) just for my USB 1.1 devices.

My first day with Fedora

Yesterday I switched my home desktop from Ubuntu 13.10 to Fedora 19 to have work environment ready for my Red Hat tasks.

Installation was easy as Fedora installer does not ask too many questions. But also does not give any software choice so I took KDE one. Made a backup of Ubuntu rootfs and /home partition and 10 minutes later I was running same X11 session but with Fedora logo in a corner.

Installing extra packages is argh… There is yum and basically nothing else. I tried Apper and Yumex — none of them was useful. Apper was unable to remove Konversation and message I got was useless (“some package depend on it” like). Yum did not have any objections. Yumex was even worse as it gave me a list of all packages without any grouping applied. Even “dselect” was better in 1999 when I started with Debian.

So I installed APT. This one works but only kind of… “apt-cache search something” takes eons, installing packages is impossible due to a way how RPM works…

Because RPM allows to have more than 1 version of package installed at same time. WHY? How it is supposed to work at all??? And no, I did not have any filesystem corruptions or something like that…

Anyway those problems can be bypassed or ignored. But then there are other ones. I always thought that Debian legal team has very strict rules about what can go into distribution. Fedora proved that I was wrong. External repositories are a must have here. MP3 or AAC playback? Forget. Probably also video playback etc. Want Google Chrome? Forget. I understand why Adobe Flash is not in repo (but there is one with it as well) but all that? Probably there are more entries here but I did not yet finished installing stuff I use/need.

Will have to add few tweaks here and there (like bumping “nr_uarts” kernel option to have all 7 serial ports) but it works. And I like “journalctl -b” way of checking what was going on since system boot ;D

New boot setup of my Chromebook

After several recompilations I finally got what I wanted on my Chromebook. Clean and easy way of booting own kernel.

Now situation is clean and easy:

  • power on Chromebook
  • ChromeOS U-Boot from SPI flash starts
  • white screen of warning appears
  • Ctrl-d to skip it
  • U-Boot starts from mmcblk0p1
  • U-Boot reads boot.txt from mmcblk0p2 (ext2 /boot/ partition)
  • U-Boot reads uImage kernel and exynos5250-snow.dtb file from mmcblk0p2
  • Kernel boots directly to Fedora F19 stored on mmcblk0p3

This way I can quickly test mainline kernels (but this may require U-Boot change for simplefb support), manipulate 3.[48]-chromeos ones etc.

Next step would be replace bootloader stored in SPI flash but this voids warranty so let it wait a bit.

Booted mainline kernel on Chromebook

Olof Johannson wrote on Google+ how to get mainline kernel booting on Samsung ARM Chromebook. As mine returned from repair with new speakers and bottom cover I decided to take a look.

With chainloaded U-Boot and just standard “exynos_defconfig” build of 3.11-rc2 I got my machine booting to Ubuntu right away:

00:06 hrw@krolik:~$ cat /proc/device-tree/model ;echo
Google Snow
00:06 hrw@krolik:~$ uname -snrp
Linux krolik 3.11.0-rc2 armv7l

There are some things missing (audio, usb 3.0, backlight and more) but even with what is available we can boot and use Chromebook with mainline kernel instead of ChromeOS one.

I will revert to 3.4-chromeos for now and try 3.8-chromeos one but that’s because I use Chromebook as developer machine for some builds where storage speed matters.

RedHat and real AArch64 hardware today

In around 3 hours from now Jon Masters from RedHat will have first live multi-node cluster 64-bit ARM silicon demo running Fedora. On real hardware…

It amazing how it went from new architecture announcement though simulators, boostrapping distributions to running those on real hardware. When I was working on AArch64 we were said that it will take one more year before we see devices not emulators or FPGAs (which I heard were slower than simulator).

I hope to work on AArch64 support again — one day in a future.

BTW — there will be no live streaming but Jon wrote that there will be video posted in short time after.

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.

Linux 3.9 and Chromebook support

Linus Torvalds released Linux 3.9 and many websites published summaries what’s new in it. One of common entries is support for ChromeOS laptops. But what that means for Samsung ARM Chromebook users?

Let’s start with Kernel Newbies summary which lists 5 commits:

None of them are for ARM Chromebook. But that does not mean that nothing was done for it. Touchpad driver was merged, many Exynos platform changes were made but yeah — still lot to do.

But that’s a curse of ARM platforms…

UPDATE: Arnd Bermann wrote a comment on my Google+ post that Olof Johansson has “linux-next” bootable on ARM Chromebook. YAY!

UPDATE: I got ChromeOS 3.8 kernel running on my Chromebook. Needs some testing and then will land in “saucy” as default one probably.