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Odi's astoundingly incomplete notes

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Gentoo to require initramfs

A Portage news item announces today that Gentoo is about to upgrade to udev-217. This upgrade will eliminate the userspace firmware loader. The change requires not only a kernel config change (CONFIG_FW_LOADER_USER_HELPER=N). It also may require an initramfs, if the kernel has drivers built-in that want to load firmware before the root filesystem is mounted. Examples of such drivers are: iwlwifi (Intel WiFi chips) or bnx2 (Broadcom NetXtreme II). Without userspace fw loading these drivers will fail to load their firmware. The standard solution to this problem is to use an initramfs.

A module-less initramfs is sufficient for that case (modules are built-in already), and it can easily be shared among different kernels.


posted on 2014-11-10 10:30 CET in Code | 0 comments | permalink

interactive diff merge on the console

To quickly compare and merge files ver1 and ver2 and save the result as merged:
sdiff -s -o merged ver1 ver2
It's the command that Gentoo's etc-update uses.
posted on 2014-09-18 18:20 CEST in Code | 0 comments | permalink

Gentoo fails to build dev-libs/boost-1.52.0-r7

If you get this:
ln -f -s 'libboost_wave.so.1.52.0' 'stage/lib/libboost_wave.so'

...failed updating 1 target... 

Then put this into your /etc/portage/package.use:
# boost 1.52 is broken with current icu
<dev-libs/boost-1.53 -icu

posted on 2014-08-02 12:31 CEST in Code | 1 comments | permalink
Just to ser how it is done. Nice work.

iOS and hostapd

If you want iOS devices to connect to your hostapd AP, then you must not configure SHA256. Unbelievable, Apple! You get offered a choice between two options and you just decide to fail?!?

#wpa_key_mgmt=WPA-PSK WPA-PSK-SHA256
wpa_key_mgmt=WPA-PSK


posted on 2014-07-30 22:35 CEST in Code | 0 comments | permalink

How not to design an API

Reading up on how to remotely connect to a JMX port, I wonder how one can possibly design such a horrible API. According to that document you need to create an URI string and pass that to the API. The URI string looks like this:
service:jmx:rmi:///jndi/rmi://hostName:portNum/jmxrmi
Utterly unintuitive, error prone and unreadable. And why assemble an URI string, pass it through an underpowered API and then parse that apart in the implementation again? Like somebody deliberately wanted to piss people off.

It could have been as simple as this:
JMXConnectorFactory.connect(host, port);
Because that's all people normally do! Yes, there may be one person in the Universe that wants to exchange the RMI transport with something else. But the API makes everybody pay with that:
MXServiceURL u = new JMXServiceURL(
  "service:jmx:rmi:///jndi/rmi://" + hostName + ":" + portNum +  "/jmxrmi");
  JMXConnector c = JMXConnectorFactory.connect(u);

posted on 2014-07-14 09:59 CEST in Code | 0 comments | permalink

Preventing systemd on Gentoo

With the latest upower upgrade portage may pull in systemd. If you are like me and think that systemd has grown beyond what it should do and you don't want it, do this:

/etc/portage/package.mask:
sys-apps/systemd
Then replace upower with the compatibility layer:
emerge -C sys-power/upower
emerge -1 sys-power/upower-pm-utils

posted on 2014-06-03 13:25 CEST in Code | 1 comments | permalink
Thank you! I really don't like systemd and the attitude of its developers. It just seems horrible all around, so thanks for helping me not install it on Gentoo!

bnx2 firmware and PXE bootable kernel

I am building a Linux kernel that is booted via the network with PXE. The machine that runs it has a Broadcom network card that uses the bnx2 driver. That card needs firmware to function, which is normally loaded into the card by udev.

As the kernel boots it obtains an IP via DHCP and mounts its root file system over NFS. For that it needs a working network card and hence the firmware. Of course the firmware can not be on NFS and there is no udev to load it yet. Hence the kernel must load it. If you don't want an initramfs (because it's a PITA to build), you need to build the firmware into the kernel.

The kernel has config options to build firmware blobs into the kernel. They are found under:
 Device Drivers
   Generic Driver Options
     [*] Include in-kernel firmware blobs in kernel binary
     () External firmware blobs to build into the kernel binary
     (/lib/firmware) Firmware blobs root directory
and they map to the .config variables FIRMWARE_IN_KERNEL, EXTRA_FIRMWARE and EXTRA_FIRMWARE_DIR.

EXTRA_FIRMWARE is a space separated list of file names of the firmeware blobs.
EXTRA_FIRMWARE_DIR is a slash terminated directory where those files are.

Now you first need to know which versions of these files are requested by the driver:
# cd drivers/net/ethernet/broadcom/
# grep \\.fw bnx2.c
#define FW_MIPS_FILE_06         "bnx2/bnx2-mips-06-6.2.3.fw"
#define FW_RV2P_FILE_06         "bnx2/bnx2-rv2p-06-6.0.15.fw"
#define FW_MIPS_FILE_09         "bnx2/bnx2-mips-09-6.2.1b.fw"
#define FW_RV2P_FILE_09_Ax      "bnx2/bnx2-rv2p-09ax-6.0.17.fw"
#define FW_RV2P_FILE_09         "bnx2/bnx2-rv2p-09-6.0.17.fw"
So you should list exactly these names in EXTRA_FIRMWARE. To make it extra difficult the kernel itself doesn't even contain these versions:
# ls firmware/bnx2
bnx2-mips-06-6.2.1.fw.ihex   bnx2-rv2p-06-6.0.15.fw.ihex  bnx2-rv2p-09ax-6.0.17.fw.ihex
bnx2-mips-09-6.2.1a.fw.ihex  bnx2-rv2p-09-6.0.17.fw.ihex
But fortunately the firmware is distributed separately and should already be in /lib/firmware. On Gentoo these files are installed by the ebuild sys-kernel/linux-firmware.
# ls /lib/firmware/bnx2
bnx2-mips-06-4.6.16.fw     bnx2-mips-09-5.0.0.j3.fw  bnx2-rv2p-06-6.0.15.fw
bnx2-mips-06-5.0.0.j3.fw   bnx2-mips-09-5.0.0.j9.fw  bnx2-rv2p-09-4.6.15.fw
bnx2-mips-06-5.0.0.j6.fw   bnx2-mips-09-6.0.17.fw    bnx2-rv2p-09-5.0.0.j10.fw
bnx2-mips-06-6.0.15.fw     bnx2-mips-09-6.2.1a.fw    bnx2-rv2p-09-5.0.0.j3.fw
bnx2-mips-06-6.2.1.fw      bnx2-mips-09-6.2.1b.fw    bnx2-rv2p-09-6.0.17.fw
bnx2-mips-06-6.2.3.fw      bnx2-mips-09-6.2.1.fw     bnx2-rv2p-09ax-5.0.0.j10.fw
bnx2-mips-09-4.6.17.fw     bnx2-rv2p-06-4.6.16.fw    bnx2-rv2p-09ax-5.0.0.j3.fw
bnx2-mips-09-5.0.0.j15.fw  bnx2-rv2p-06-5.0.0.j3.fw  bnx2-rv2p-09ax-6.0.17.fw
So you must set EXTRA_FIRMWARE_DIR = /lib/firmware/.

With these options correctly set, such a kernel boots perfectly over PXE.


posted on 2014-05-02 16:56 CEST in Code | 1 comments | permalink
merci Odi

Eclipse crashes in KDE

If your Eclipse (Kepler) crashes a lot in KDE it may be due to a bug in the Oxygen GTK theme. Simple solution: set a different theme.

In Gentoo first install more themes with
emerge -av gtk-engines

Then go to KDE's System Settings an chose the Application Appearance App. In the GTK Tab, select the Clearlooks GTK2 theme (and the Default GTK3 theme). I also recommend the font setting Sans Serif 10.

posted on 2014-04-21 11:14 CEST in Code | 2 comments | permalink
Oh Yeah - You are the MAN !

That was driving me nuts.

Thanks you * Thank you
For me, this helped:
http://nouseforname.de/eclipse-crash-nach-update-auf-kubuntu-14-04-verhindern/

My favourite .kshrc

/bin/bash

posted on 2014-03-18 14:38 CET in Code | 0 comments | permalink

Apache hickup after glibc update

Gentoo recently updated glibc. After that I saw this in Apache's error_log:
/usr/sbin/apache2: relocation error: /lib64/libresolv.so.2: symbol __sendmmsg, version GLIBC_PRIVATE not defined in file libc.so.6 with link time reference


Re-emerge apache to fix it.

posted on 2014-01-30 18:36 CET in Code | 0 comments | permalink