path: root/index.txt

Linux Kernelprogrammierung

http://beagleboard.org/project

LWN - summary:
==============

29.04.2011:
^^^^^^^^^^^

2.6.39-rc4, released on April 18

more commits in -rc4 than in -rc3

problem:

The plugging code still seems to trigger some issue with what looks
like an infinite stream of disk-change notifications on CD-ROMs - but
Jens is hopefully going to squish that problem soon. In the meantime,
you can avoid the problem by either running SMP or having preemption
enabled.




2.6.39-rc5, released on April 26

Another week, another keyboard destroyed by spilling coffee on it..
C'est la vie.

I've been alternately kicking myself for merging it, and just being so
pleased with the rcu pathname walk now extending outside of the
no-security confines ... I dunno. The patches are all pretty simple
(there's also a few dentry cleanup patches that were the result of me
looking at profiles and generated code), and it really is a rather
important performance thing, but at the same time I would shout at
others for trying to merge it to me this late. So I'll consider myself
properly chastised.

Other than that?

We should have all the fallout from the block layer
plugging changes fixed now, and Tejun fixed the infinite CD-ROM
disk-change notification thing. So that's hopefully all good and done.

The diffstat actually looks pretty good, most of it is
just one-liners and stuff like a few new device ID's etc.


Quote of the week

There really are only two acceptable models of development: "think and analyze"
or "years and years of testing on thousands of machines". Those two really do
work.
-- Linus Torvalds





14.04.2011:
^^^^^^^^^^^

2.6.39-rc3 is out:

It's been another almost spookily calm week. Usually this kind of
calmness happens much later in the -rc series (during -rc7 or -rc8,
say), but I'm not going to complain. I'm just still waiting for the
other shoe to drop.

And it is possible that this really ended up being a very calm release
cycle. We certainly didn't have any big revolutionary changes like the
name lookup stuff we had last cycle. So I'm quietly optimistic that no
shoe-drop will happen.

Anyway, not only has it been calm, it's been pretty normal. Two thirds
drivers is pretty normal, with the rest being fairly spread out all
over.

Let's hope the release cycle continues like this. I _like_ it when
people really seem to follow the whole "big changes during the merge
window" rules.

Thanks guys,

                   Linus
...
Artem Bityutskiy (10):
      UBIFS: do not read flash unnecessarily
      UBIFS: fix oops on error path in read_pnode
      UBIFS: fix assertion warnings
      UBIFS: do not select KALLSYMS_ALL
      UBIFS: unify error path dbg_debugfs_init_fs
      UBIFS: fix error path in dbg_debugfs_init_fs
      UBIFS: fix debugging failure in dbg_check_space_info
      UBI: check if we are in RO mode in the erase routine
      UBI: do not compare array with NULL
      UBI: do not select KALLSYMS_ALL

Ben Dooks (1):
      gpio/pca953x: fix error handling path in probe() call

Bryan Schumaker (2):
      NFS: Fix a signed vs. unsigned secinfo bug
...


08.04.2011:
^^^^^^^^^^^

Quotes of the week II: in memoriam

Linux has lost a great developer with the passing of David Brownell recently
	and he will be greatly missed.
	-- Greg Kroah-Hartman

David made contributions to a large number of areas in the Linux kernel. Even
	a quick look through MAINTAINERS will show that he worked on USB controllers
	(OHCI, EHCI, OMAP and others), USB gadgets, USB networking, and SPI. He was
	influential in the core USB design (the HCD "glue" layer and the
	scatter-gather library) and the development of Power Management (system sleep
	and the USB PM implementation). His designs were elegant and his code was
	always a pleasure to read.

	He also was a big help to me personally, assisting in my initial entry to USB
	core development. And he was the first person I met at the first Linux
	conference I attended. I too will miss him.
	-- Alan Stern

I guess many of us have similar experience with Dave. He also helped me a lot
	when I first started doing Linux development. I learned a lot from him and
	will miss him a lot. His teachings, I will always carry with me.
	-- Felipe Balbi



- 2.6.39-rc2 is out

35% arch (ARM and power, some unicore32 cleanups)
35% drivers (net, input and some drm)
30% random (doc updates, perf, net, btrfs).

Because it's such a small -rc, I'm appending the shortlog, something I usually
don't get to do until -rc3 or -rc4.

This should hopefully fix up the most annoying -rc1 problems. We had a
couple, like the plugging issues with the IDE layer, causing some
machines to not boot. Or the tty-full-and-hung one. And just the small
fallout from the irq cleanups (which affected a couple of less common
platforms).

But on the whole really not a lot. Which is sincerely _hope_ is a sign
that 2.6.39 is going to be a simple release.

Knock wood. Go out and test,

                          Linus



- GNOME 3 is released


01.04.2011:
^^^^^^^^^^^

- GCC 4.6.0 is out  support for the Go language, improved C++0x support, many
		optimization improvements including a "scalable whole program optimizer"
		which is said to be stable enough to use, a new -Ofast option, and more..

- 2.6.39-rc1 is out

There have been just over 2,200 non-merge changesets pulled into the mainline
since last week; that makes 8,757 total changes for this development cycle.

- an option to force all interrupt handlers to run as threads

- The media controller subsystem

- The CHOKe packet scheduler

- There is a new "mtdswap" block device which allows swapping directly to
		memory technology devices.

- printk() and friends have a new "%pB" format specifier which prints a
		backtrace symbol and its offset.

- Jump Label reworked

    #include <linux/jump_label.h>

    struct jump_label_key my_key;
Enabling and disabling the key is a simple matter of calling:

    jump_label_inc(struct jump_label_key *key);
    jump_label_dec(struct jump_label_key *key);
And using the key to control the execution of rarely-needed code becomes:

    if (static_branch(&my_key)) {
	/* Unlikely stuff happens here */
    }

The 2.6.39 kernel now goes into the stabilization phase of the development
cycle. If the usual pattern holds, we can expect to see on the order of 2000
fixes merged between now and the final release, which is likely to happen in
early June.


Quotes of the week

The C preprocessor... It is ugly, inelegant, painful, annoying, and should have
been strangled at birth -- but it is always there when you need it!
-- Paul McKenney

Make Linux Software presents the fastest ever embedded Linux boot for 720 MHz
ARM and NAND flash memory. Linux boot time is 300 milliseconds from boot loader
to shell.
-- Constantine Shulyupin



25.03.2011:
^^^^^^^^^^^

- As always lots of new drivers :))

Processors and systems: VIA/WonderMedia VT8500/WM85xx System-on-Chips,
IMX27 IPCAM boards, and MX51 Genesi Efika Smartbook systems.

Block: Broadcom NetXtreme II FCoE controllers and
Freescale MXS Multimedia Card interfaces.

Graphics: Intel GMA500 controllers (2D acceleration only),
USB-connected graphics devices, MXS LCD framebuffer devices,
and LD9040 AMOLED panels.

Input: Hyper-V virtualized mice, Roccat Kova[+] mouse devices,
Roccat Arvo keyboards, Wolfson WM831x PMIC touchscreen controllers,
Atmel AT42QT1070 touch sensor chips, and
Texas Instruments TSC2005 touchscreen controllers.

Networking: Texas Instruments WiLink7 bluetooth controllers (from staging),
Bosch C_CAN controllers, Faraday FTMAC100 10/100 Ethernet controllers,
and the Xen "netback" back-end driver.

Miscellaneous: Faraday FUSB300 USB peripheral controllers,
OMAP USBHS host controllers, NVIDIA Tegra USB host controllers,
Texas Instruments PRUSS-connected devices, MSM UARTs,
Maxim MAX517/518/519 DACs, RealTek PCI-E card readers,
Analog Devices ad7606, ad7606-6, and ad7606-4 analog to digital converters,
Maxim MAX6639 temperature monitors, Maxim MAX8688, MAX16064, MAX34440 and
MAX34441 hardware monitoring chips,
Lineage compact power line power entry modules,
PMBus-compliant hardware monitoring devices,
Linear Technology LTC4151 is high voltage I2C current and voltage monitors,
Intel SCU watchdog devices, Ingenic jz4740 SoC hardware watchdogs,
Xen watchdog devices, NVIDIA Tegra internal I2C controllers,
Freescale i.MX28 I2C interfaces, MXS Application UART (AUART) ports,
SuperH SPI controllers, Altera SPI controllers, OpenCores tiny SPI controllers,
SMSC SCH5627 Super-I/O hardware monitoring chips,
Texas Instruments ADS1015 12-bit 4-input ADC devices,
Diolan U2C-12 USB adapters, SPEAr13XX PCIe controllers (in "gadget" mode),
and Freescale MXS-based SoC i.MX23/28 DMA engines.

Sound: Firewire-connected sound devices, Wolfson Micro WM8991 codecs,
Cirrus CS4271 codecs, Freescale SGTL5000 codecs, TI tlv320aic32x4 codecs,
Maxim MAX9850 codecs, and TerraTec 6fire DMX USB interfaces.

Outgoing: A number of TTY drivers
(epca, ip2, istallion, riscom8, serial167, specialix, stallion, generic_serial,
rio, ser_a2232, sx, and vme_scc) have been moved to the staging tree in
anticipation of removal in 2.6.41.

The smbfs and autofs3 filesystems, which were moved to staging in 2.6.37, have
now been moved out of the kernel entirely.

- BKL http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=4ba8216cd90560bc402f52076f64d8546e8aefcb

- New syscall: int syncfs(int fd);

- The USB core has gained support for USB 3.0 hubs

- New Dynamic Debugging Features

	tpm_nsc.c
	346: dev_dbg(&pdev->dev, "NSC TPM detected\n");

	echo file tpm_nsc.c line 346 +p > .../dynamic_debug/control
	echo file tpm_nsc.c line 346-373 +p > .../dynamic_debug/control
	echo file tpm_nsc.c function init_nsc +p > .../dynamic_debug/control

- new set of string-to-integer converters which is expected to be used in
		preference to all others.

		Unsigned conversions can be done with any of
		kstrtoull(), kstrtoul(), kstrtouint(), kstrtou64(), kstrtou32(),
		kstrtou16(), kstrtou8().

		Conversions to signed integers can be done with
		kstrtoll(), kstrtol(), kstrtoint(), kstrtos64(), kstrtos32(), kstrtos16(),
		or kstrtos8().

	All of these functions are marked __must_check, so callers are expected to
	check to ensure that the conversion happened successfully. The older
	functions are marked deprecated, and will eventually be removed. These new
	kstrto*() functions are now the Official Best Way To Convert Strings, so
	developers need wonder no longer.

Linuxtag:
=========
Mi 11. - Sa 14. Mai Messe Berlin - Vorlesung entfällt

Excursion from 10th to 15th of May.
Conference Schedule online

Costs:

Hier könnte man im Doppelzimmer für 15 EUR / Person / Tag übernachten:
http://www.winters-hotel-berlin-city-messe.de/

RV ab Di, 10.05. 21:04, Berlin an Mi, 11.05. 07:20 (2 x umsteigen) 234 EUR
Berlin ab So, 15.05. 12:42, RV an So, 15.05. 21:07 (3 x umsteigen) 359 EUR

Hinfahrt	Bahnhof/Haltestelle	Datum	Uhrzeit	Produkte	Reservierungswunsch
 	Ravensburg
Ulm Hbf	Di, 10.05.2011	21:04
21:58	IRE 3363	Reservierung nicht möglich
 	Ulm Hbf
Mannheim Hbf	Di, 10.05.2011	22:04
23:42	ICE 990	5 Plätze in der 2. Klasse, Großraum mit Tisch, Ruhebereich
 	Mannheim Hbf
Berlin Hbf (tief)	Di, 10.05.2011	23:59
07:20	CNL 1259	Reservierungspflichtiger Zug, 5 Plätze in der 2. Klasse
Rückfahrt	Bahnhof/Haltestelle	Datum	Uhrzeit	Produkte	Reservierungswunsch
 	Berlin Hbf (tief)
Nürnberg Hbf	So, 15.05.2011	12:42
17:24	ICE 109	5 Plätze in der 2. Klasse, Großraum mit Tisch, Ruhebereich
 	Nürnberg Hbf
Aalen	So, 15.05.2011	17:39
19:01	IC 2062	5 Plätze in der 2. Klasse, Großraum mit Tisch
 	Aalen
Ulm Hbf	So, 15.05.2011	19:07
19:54	IRE 3235	Reservierung nicht möglich
 	Ulm Hbf
Ravensburg	So, 15.05.2011	20:12
21:07	IRE 4215	Reservierung nicht möglich
Ihr Ticket	 HIN- UND RÜCKFAHRT, 5 Erw., 2. Klasse, Hin: Sitzplatz, 5 Personen im Ruhesessel Großraumwagen, Ravensburg - Berlin, Berlin - Ravensburg
Sparpreis
Zugbindung. Umtausch/Erstattung 15 EUR; ab 1. Geltungstag ausgeschlossen
Inkl. Nachtzugaufpreis, reservierungspflichtiger Zug enthalten (Preis inkl. Res.), Anschlussreservierung kostenpflichtig	 593,00 EUR
Reservierung	Hinfahrt:
Rückfahrt:	12,50 EUR
12,50 EUR
Gesamtpreis	618,00 EUR

Damit läge die Zugfahrt bei ca. 118 EUR / Person + 60 EUR übernachtung (im
Doppelzimmer) + 16 EUR Eintritt Linuxtag + ca. 15 EUR U-Bahn Tickets
(Gruppentageskarte 5 Pers. 15 EUR * 5 Tage)

--> ~210 EUR

maybe 50 - 70 EUR grant from University

Plesae mail me until Monday if you want to join. (manut@mecka.net)

Prüfung:
========
schriftlich, 60 Minuten

Material:
=========
http://manut.eu/hswgt

Script:
=======
Mitschriebe gerne an
manut@mecka.net

Literatur:
==========
http://lwn.net
http://heise.de/open <-- Kernel Log
http://kernelnewbies.org
http://beagleboard.org

Corbet, Rubini, Kroah-Hartmann: Linux Device Drivers 3rd Edition
  http://lwn.net/Kernel/LDD3

Kroah-Hartmann: Linux Kernel In A Nutshell
  http://www.kroah.com/lkn

Bovet, Cesati: Understanding The Linux Kernel (34,95)

Love: Linux Kernel Development (29,95 EUR)

Bewertung:
==========
http://www.meinprof.de/uni/prof/51131

weitere Termine:
================
03. Juni Blutfreitag Vorlesung entfällt
17. Juni Pfingsten Vorlesung entfällt
01. Juli letzte Vorlesung

geplante Themen:
================

UE0 - what is linux:
--------------------
Linux Desktop vs. embedded Linux:
 - Kernel vs. Userspace
 - Fedora, Debian, ubuntu ..
 - Android
 - KDE / GNOME
 - CPU Architekturen
 - cross

UE1 - kernel basics, kernel best practices, kernel api:
-------------------------------------------------------
Kernelentwicklung
  - Mainline / Maintainer
  - syscalls (stabil)
  - interne API (instabil)
  Versionskontrolle:
    - diff / patch
    - quilt
    - git

UE2 - kernel build, bootloader:
-------------------------------
Board Bringup:
 - Bootloader
 - grub vs. IPL vs. u-boot

Kernel:
 - Kernel konfigurieren
 - Kernel kompilieren (auch cross)
 - Kernel Dokumentation

UE3:
----
Dateisysteme:
  Desktop:
  - ext2/3/4 - xfs
  Embedded:
  - jffs2 - ubifs
  Flash:
  - SDCard, CF vs. NAND
  Netzwerk:
  - NFS

UE4:
----
Userspace:
 - RFS generieren
 - busybox / cross
 - read only RFS
 - 'kein' RFS vs. full-featured Debian

UE5:
----
Kernelarchitektur:
  - Core
  - Driver
  - Arch
  - Coding Style

UE6:
----
Kernelmodule:
  - 1. Kernelmodul 'Hello world'
  registrieren bei Subsystemen:
  - char dev

UE7:
----
Tracing

UE8:
----
Kernelkonzepte:
  Review eines Treibers:
    - IRQ Handling
    - MM
    - Timer

UE9:
----
Echtzeit:
  - RTAI vs. RT_PREEMPT
  - Grenzen
  - cyclictest
 
UE10:
----
UIO:
  - UIO LPT Beispiel
  - RT Performance messen

UE11:
-----
MIDI:
  - Basics
  - Midi & Linux

UE12:
-----
IRQ Handling, Locking, ..

UE13:
-----
ALSA:
  - Kernel-/Userspace-Architektur
  - Tools
  - Synthesizer

UE14:
-----
Linux & Grafik oder ein anderes aktuelles Thema

UE15:
-----
Q&A tglx