Personal Data

Name: Seibold
Given name: Stefani Michaela Andrea
Age group: 1964
Nationality: German


Project experience

Current skills

Preferred projects

Older skills

Qt, Java, MS SourceSafe, CVS, QNX, VxWorks, LynxOS, PSOS+, Pascal/Delphi, Forth, Basic, X.25 (X.29), VAX, PDP-11, Cray, 8-Bit Computer (6502 and Z80), 68000er Assembler, MS-DOS, CP/M, Telex, Protocols (Kermit, X-, Y- and Z-Modem), OSI 7 Layer model


English and technical English, hardware know-how, fundamental electronics knowledge, administration know-how, editorial activities

Unwanted Projects

Professional goals


Working places:

In the region of Munich and/or remote (home office), maybe abroad in a sunny country ;-)

Payment or hourly rate:

By arrangement.

Professional CV and project experiences

Linux kernel development

FAT mount Dirty Fix

Device Tree Overlay fixes for external references

VDSO timer functions for x86 32 bit (mergend in kernel 3.15).

USB Skeleton fixes.


Analysis and fix of a high latency bug related to CFI flash memory.

Analysis of a high latency bugs in the PHY Code (Busy waiting).

Extended implementation of the kernel FIFO API on basis of C-macros, in order to administer arbitrary data type in FIFO (intended for merge in the 2.6.34).

Documentation of the proc file system in the kernel source tree under documentation/filesystems/proc.txt updates.

Fix /proc/<pid>/stat for the correct start address of a process/thread stack and to mark this in the entry in /proc/<pid>/maps and/or smaps.

Stack Usage Monitoring Patch

Git, Linux kernel patches, USB, filesystems, VDSO, device tree, kernel API

2018-2019 - Drivelock (Freelance)

Prototype for a user space system call tracer which runs at least on linux kernel 3.2

Generate a Yocto buildsystems for a distribution independet SDK and libraries which are based on linux kernel 3.2

Implementation of a security monitor programm that intercepts arbitrary system calls, analyzes them and rejects them according to the programmed rule, e.g. Write on an unauthorized disk.

Implementation of the security monitor as an init prozess, which monitors the whole Linux system, including all prozesses of the root user.

Yocto, Linux, Seccomp, C++14

2018 - Rohde & Schwarz (Freelance)

Implementation of a runtime profilers (rsprof) which backtrace capabilities in C++14 under GPL license, which provides the following features:
Implementation of an ELF File Format Linter's (libcoverage) in C++14 under GPL Lizenz which provides the following features:
C++14/17, Clang, Clang-Tidy, Linux, Elf, Ptrace

2016-2018 - MSWestfalia (Freelance)

Creating a Yocto build layer, the SDK and the Root Filesystem for an ARM iMX.6 base medical breathing device, including project specific bitbake recipes.

Porting the Yocto build layer for the iMX.6 device to a new Yocto buildsystem for a Nvidia Tegra base device, also merging the latest Boot2Qt Qt layer.

Yocto, iMX.6, Nvidia Tegra

2016-2017 - Huawei (Freelance)

Reverse engineering and porting of a Linux kernel for the Taishan 2180/2280 server (32 ARM64 Cores):
RDMA and RoCE tests and benchmarking.

BMC, IPMI, RDMA, RoCE, ARM64, Linux, KVM, NUMA, Device-Tree, Git

2016 - Rohde & Schwarz (Freelance)

Implementation of an USB Frontpanel controller using Atmel SAM3 ARM Cortex M which provides the following features:
ARM Cortex M, USB Host and Target, Atmel Boot Loader

2016 - FA. Förster (Freelance)

Implementation of a generic Linux PCIe drivers which allows userspace application to map and handle the device.

2015-2016 - ARRI (Freelance)

Investigation of a memory corruption bug in the Linux kernel (which was a wrong setup of a DDR3 memory)

Implementation of a Linux PCIe root driver for an Altera FPGA

Upgrade of a distributer specific Linux kernel 3.14 for a Marvell Armada ARM CPU to kernel 4.0

Linux, DDR3 Memory Timing, PCIe Root Complex

2015 - Rohde & Schwarz (Freelance)

Implementation of an online memory leak debugger under GPL license ( which provides the following features: Linux, Ptrace, Debugger, C

2015 - PSysteme (Freelance)

Writing a Linux driver for a high speed camera (up to 1000 frames/sec.) which prevents frame drops (CPU PowerPC).

Improved bring up system which decrease the time spent by magnitudes.

Optimization and shrinking of device root filesystem

ELDK, Linux, PowerPC, FPGA

2005-2015 - Rohde & Schwarz (Freelance activity signal generators)

Bug fixes in the linux kernel (display issues, FAT dirty mount).

Implementation of an USB Storage for a Cortex-ARM based frequency multiplier (ZTX), as well as the target side and linux host driver.

Supply a real time double precision floating point library, because the GLIBC pow() function has a execution time jitter by a factor 12500 depending on the input arguments.

Revamp the PCIe endpoint driver to allow direct PCIe transfers from one endpoint to an other.

Add 4 bit ECC support for the Micron MT29F chip to the linux NAND driver.

Provide a board support packages for a P2020 dual core freescale based system.

Implementation of a FCGI Proxy, which terminates the FCGI server after a given time of inactivity.

Add FCGI support to the busybox HTTPD server.

Implementation of a IEC 488 Linux driver for the NI TNT500x chip. The driver is split in a logical IEC488 interface drivers and a hardware driver. The HW driver will do a register call to the logical part, which provides all IEC488 functions. This design allows an easy implementation for other HW, like FPGA or USB.

Reimplementation of a Linux USB TMC gadget driver.

Reimplementation optimized Windows and Linux C++ base classes for threads, mutexes and IPC.

Revamp the keyboard debouncing for a cypress 8 bit controller.

Bug fixes and improvements fpr an I2C to USB touch converter, which was based on a AVR32 micro controller.

Add multi touch support to Qt4 X11.

Provide a ARM Toolchain, Build Environment and root FS.

Implementation of a FUSE base ReadOnly-/WriteForget FS.

Implementation of an OS X of driver for NRP USB measuring sensors.

Implementation PCI Express endpoint kernel driver for MPC 8379. This was later split in a logical and HW specific layer.

Creating a generic Linux PCI driver kernel library and API.

Creation of a generic USB driver kernel library and API.

Creating a Intel cross compiler development environment on basis of GCC/Linux/glibc/X11 and ucLibc, as well as a build system for the kernel and the root file system and automatic generation of a bootable hybrid ISO installation CD.

Implementation of the NRP USB measuring sensor driver under Linux 2.6.

New implementation of the Windows NrpControl2.dll for power meter sensors under Linux in C++/STL.

Optimization of the Linux system startup, memory consumption and CCU resource.

Installation of the SMB PowerPC Freescale MPC 8347 hardware:

Advancement Linux for signal generators:

Linux boot time optimizations.

Analysis of portable GUI tool kits for performance in a visualization system. Implentation of an oscilloscope simulation benchmark for Qt, GTK+, Cairo, SDL and GDI.

Production of a VMWare for the Linux cross development environment, including a graphical debugger (Insight GDB).

Implementation of a GDB proxy service for inetd - to enable any time debugging.

GUI and block diagram implementation of a signal generator, on basis of Qt3.

Linux server administrator and implementation of a backup script.

Port of an IEEE488 driver from Windows to Linux without modify the source text of the driver.

C++14, ARM, Freescale PowerPC MPC's, I2C, PCIe, USB, IEEE488, Linux, Debugging, Cross-Toolchain, Intel x86, Hotplug, Window-Manager, NRP Messköpfe, Framebuffer Display, OneNand, NAND, FUSE, YAFFS2, SIM cards, Optimization of boot time and resources, C++/STL, C, Linux kernel, VMWare, GUI, Qt, VNC, FTP, HTTP, SSH, BASH, Memory Leak, GDB, Gnu toolchain, Update, X11, Clearcase, Mercurial.

2011-2012 - 4tiitoo (Freelance)

WeTab Tablet-PC:

Support to improving the already shipped x86 based tablet:
uinput, Crystal-HD, Xorg server mouse, Multitouch, Eye-Tracker, Optimization

2010 - NSN/Munich (Freelance)

Linux board support Packages for MPC 8360.

Development a generic build system for root file system.

Patch Linux 2.6.33 for a P4080 evaluation board (multi-core MPC 85xx).

2008-2013 - NSN/Ulm (Freelance)

Implementation of a driver for disabling the L1-Cache for code and data, as well as the L2-Cache during operation (MPC 8548 and MPC 8347).

Development of a stack monitoring patch for Linux the kernel.

Implementation of the UDPCP network kernel protocol stack for Linux.

Analysing and fixing a latency bug releated to the CFI flash memory.

Taltios Driver, OCF (Open Cryptographic Framework), OpenSSL, IPSec, Linux kernel extension

2006 - Rohde & Schwarz (Freelance)

Implementation of a Linux kernel driver to handle interrupts in user land programs.

Linux kernel programming, C

2006 - BenQ Mobile (Freelance)

Development of a Linux driver for a bistable display manufactured by the E Ink corporation: transform the RGB565 color space into 4 grey values by an optimized and improved Floyd Steinberg Dithering, including color space spreading and integer only calculations and a table generator implemented in python.

ARM PXA270/271, C, Python, Algorithms, framebuffer

2006 - Siemens ITS (Freelance)

Implementation of a modem server under Linux in C. Controlling of a GSM radio modem with on demand dial out, incoming call rejection and alternation between PPP and RAW connections.

GSM, Modem, C, Linux, Client-Server

2005 - Rohde & Schwarz (Freelance)

Boot time optimization of the Smartie series (SM300/UP300/AM300) from several minutes to 90 seconds. Among other things by adjustment and optimization of the Linux Bios on a 486er hardware and optimization of the Linux kernel and system environment.

Linux BIOS, i486, kernel, optimization

2005 - Siemens Mobile (Freelance)

Power Managment Linux driver for DVB-H mobile phone on basis ARM PXA270/271 using the I2C bus.

ARM PXA270/271, Linux, I2C

2002-2005 - Siemens ICN (Freelance optical networks)

Project planning and system design for a embedded Linux on PowerPC basis.

Systems programming under embedded PowerPC Linux: optimize boot time, elimination of errors in the PowerPC kernel (debugger, RTAI, IRQ handling), installation, administration, kernel- and realtime- programming.

Development of a PowerPC embedded Linux root of file system with RTAI realtime support.

Systems programming of transmission protocols for software update via download, external communication with the CAN bus, HDLC and serial interface to JDS Uniface Wave Lenght blocker and/or PQM, as well as Siemens ICN internal protocols.

Programming of libraries for pthread handling, thread to thread communication, semaphore, timer events, memory managment, post mortem debugging and exception handling.

Device driver under Linux for Intel 82527 CAN bus interface.

Port of a HDLC PowerPC 8260 Linux driver to PowerQuick MPC 860.

Programming a reset save PRAM disk driver.

Implementation of a message service for multicast IP.

Implementation of a socket CLI (command line interface).

Implementation of a life cycle managment logging in the EEPROM.

PowerPC 860 Linux, TCP/IP, CAN-Bus, SPI-Interface, HDLC, JDS WBA, JDS PQM, C, C++, BASH, PPC 860 Assembler, GDB-Server, ClearCase

2003 - Training laser safety

Voluntary education as Laserschutzbeautragten (Laser safety officier) and use of lasers in the clinical medicine.

2002 - Reilhofer KG (Freelance)

Benchmarking and hardware selection (MOPS 686+) for an analog data acquisition.

Implementation of a fixed point FFT (fast fourier transformation).

Programming the PC104+ DAS16JR analog/digital converter.

Connection of the embedded Linux system to Windows over a TCP/IP Socket.

Implementation of a mini Linux for the MOPS 686+.

2000-2001 - GEWOFAG Munich / Fa. Naeder GmbH (Freelance)

Installation of windows 95 thin clients of network, which is administered by a central Linux server.

Linux server administration, Windows, TCP/IP, Netzwerk, HA

1997-2002 - Siemens SVT (Freelance activity traffic engineering)

Linux device driver for a filesystem consistent SRAM disk.

Framework for RT-Linux and RTAI realtime development created.

Project planning and system design embedded Linux of a project.

Embedded Linux: Creation, kernel Patches, installation, administration, kernel and realtime Linux programming.

Development of a embedded Linux distribution including glibc, internet services, RT-Linux and RTAI realtime, SSH, SSL, zmodem, WLAN and debugging server (in 4MB Flash memory).

Creation of a cross development system with HTML assistance for Linux under Windows, including multithreaded suited cross debuggers with GUI for embedded Linux IA32 as target and Windows as host.

Device driver for panels, LCDisplays, serial interfaces (16450, 16550, 16650 and MC68332) under pSOS.

Systems programming of communications protocols for bootstarp, internal and external communication (direct and over various modems), as well as coupling to older transmission systems from the traffic engineering under pSOS, Linux and Windows.

Application development of a hand held device for controling a cross control device.

Windows GUI Key code generator for a cross control device using Tripel DES for creation activation codes, developed Delphi and C++.

Hardware installation and configuration as well as maintenance of PCs, IA32 and MC68xxx embedded systems, as well as production of BSP (board support Packages) for pSOS+.

Networks: Installation, configuration and operations with TCP/IP, Windows SMB and Novell IPX, file, backup and modem server under Linux, WAN, modem and GSM.

Linux, Windows, pSOS, TCP/IP, WLAN, Windows SMB, Novell IPX, Modem, GSM-Modems, C, C++, Delphi, BASH, Assembler

1993-1996 - Siemens SVT and EPA Bavaria in Munich (Employe)

Development a BASH Scripts to run and monitor the processes in a traffic control center.

Generator for Makefiles with automatic dissolution of source text dependence.

Device driver for dynamic time adjustment from different time sources.

ISA bus real time hardware driver for the modem interface (NAP /SIP Hardware) in C++ under LynxOS real-time Unix.

Implementation of test drivers for measurement of the real time characteristics of different real-time systems (pSOS, VxWorks, OS9, QNX, LynxOS, RTOS).

Spooler for a system V IPC Message queue.

Connection of special asynchronous Siemens interfaces for a visualization process.

Message converter between traffic control center and manufacturer independent STORM messages.

Emulation of an old traffic control computer on a 5 bit telex interface.

Generator for annual reports of the “environmental coverage of nuclear installations” for the Bavarian office for environmental protection (C, Wordperfect and Quattro pro macros, Basic).

Employees administration realizes with Quattro pro under DOS.

Hardware installation and - configuration as well as maintenance of PCs under LynxOS.

OOA, OOA, planning, creation of programming and project guidelines, system design, Ethernet, TCP/IP and Novell IPX, WAN, Modem- erver, LynxOS, UNIX, DOS, C, C++, BASH, Assembler

1987-1992 - MaxDat GmbH in Düsseldorf/Ratingen (Employe)

Development and maintenance of a mailbox system.

Interrupt controlled rs232 device driver for turbo pascal under DOS.

Telex and fax server for the mailbox, which passes the message automatically over the cheapest dispatching point.

Implementation of the asynchronous Kermit transmission protocol for 7 and 8-bits transmission developed under DOS and RSX-11M/+ with super Kermit extension (sliding windows, large packets).

Installation of a Novell 3.11.

Varios field service management application under DOS.

Programming a virus killers for 1701 link virus in C under MS-DOS.

Hardware installation and configuration as well as maintenance of a PDP-11 73 and 83.

Telefon-Hotline, X.25, X.29 and LAN, modem and long distance data transmission, MS DOS, PDP-11, X.25, X.29, LAN, Novell, C, Assembler

1987 - Technical book authoress and free journalist

Authoress of CHIP Special 68000er processor manual.

Co-author of CHIP Special Atari ST and CHIP Special Atari XL.

Hotline service

1986-1987 - Free technical consultant for the Bavarian broadcast in Munich

Development of a multimedia game show application for the TV quiz "Supergrips".

Amiga OS, Basic, Assembler 68xxx

1985-1986 - Freelancer

Hardware level software developments and process controls on 8-bit computers.

Development of various tiny computer games.

Implementation of a in house monitor programm.

Basic, Assembler, Commodore C64, PIO

1984-1985 - Software Express in Düsseldorf

Long distance data transmission: Development of protocols and terminal programs.

Development of a mailbox software

Basic, Assembler (6502), IBM-PC, C-64, long distance data transmission

1979-1984 - Hobby Computer

1979 - Visit of voluntary computer science workgroup, with a final grade of “very good”.

Since then computer was my hobby, which I financed by smaller orders, publishing programs in computer journals and development of computer games.

The computers did change during that time (KIM 1, Pet 2001, VIC 20, C64, Atari ST, Casio PB1000, CP/M and MSDOS PC), but not the enthusiasm!

Last update: April 29 2019