Embedded Systems Design Europe - April 2008 - (Page 32)

linux the graphical trace visualization tool (for more information, read the LTT reference manual at www.opersys.com/LTT/ dox/ltt-online-help/index.html). Eventually all embedded systems projects reach the optimization phase where a good proﬁler can come in handy. OProﬁle is a systemwide proﬁler for Linux that’s capable of proﬁling user space applications, kernel code, and loadable modules. The OProﬁle software package consists of kernel code, userspace daemon, and utilities. Fortunately, no kernel patching is required as OProﬁle is part of the stock Linux 2.6 kernel. A typical OProﬁle session looks like: opcontrol —vmlinux =/path/to/vmlinux opcontrol —start #execute your code opreport -l /path/to/mybinary opcontrol —reset you to read more at oproﬁle.sourceforge. net/doc/index.html. An important tip for embedded developers is that they can ﬁlter proﬁling results by modules, which can be a driver, an application, or the kernel itself. Note that OProﬁle is a statistical proﬁler, which means it samples program-counter values on interrupt (usually timer interrupt), so you must run the code for some minimal time period to get meaningful results. If your hardware is like most, and has performance counters that can generate an interrupt on such events as cache miss, you can ﬁnd not only the most CPU-intensive pieces of code, but also the most cache inefﬁcient. Unless you use an exotic CPU, OProﬁle will already have support for performance counters of that CPU. BINDING IT ALL TOGETHER Although it’s not necessary and can even make things more complex, if you’re more comfortable with a monolithic IDE-like software package that can do all your daily tasks using keyboard shortcuts and menus, the simplest way to do this is to create a new Emacs menu called “Embedded” and add all your scripts to that menu. The example in Listing 3 (Emacs Lisp code The ﬁrst two commands start the proﬁler, opreport prints the results, and the last command resets the data. OProﬁle is a powerful proﬁler with many features, all of which are outside the scope of this article, but I encourage that should be added to your .emacs ﬁle) illustrates this. Full explanation of this code requires some Lisp knowledge (and beyond the scope of this article), but a brief description of each command will be given, so you can customize the code and add new functionality without a full understanding of Lisp and Emacs internals. The ﬁrst set of commands creates the “Embedded” drop-down menu. The second one adds a new entry “Program ﬂash” to the menu that executes the “program-ﬂash” Lisp function. The third set binds that command to “Ctrl-c” followed by a “pf” key combination. The ﬁnal one is a Lisp function that executes a “program-ﬂash.sh” shell script redirecting its output to a newly created Emacs buffer. Creating an embedded Linux development environment by yourself may look like a serious task. But keep in mind that this is a good investment. This task can be easily outsourced to an embedded Linux consultant, in which case it’ll probably cost less than an off-the-shelf embedded Linux IDE. Note that in the Linux world, there many different ways to accomplish the same task. This article shows just one of those alternatives. Alexander Sirotkin works for Metalink Broadband as a software architect. For more than 10 years, he’s been dealing with software, operating systems, and networking, and holds M.Sc. and B.Sc. degrees in applied statistics, computer science and physics from Tel-Aviv University. Sirotkin can be reached at sasha.sirotkin@gmail.com. Listing 3 Emacs Lisp code that should be added to your .emacs ﬁle to create IDE-type keyboard shortcuts. (deﬁne-key global-map [menu-bar embedded] (cons “Embedded” (make-sparse-keymap “Embedded”))) (deﬁne-key global-map [menu-bar embedded program-ﬂash] ‘(“Program ﬂash” . program-ﬂash)) (deﬁne-key global-map “\C-cpf” ‘program-ﬂash) (defun program-ﬂash () “Program ﬂash.” (interactive) (setq embedded-buffer (get-buffer-create “Embedded Buffer”)) (display-buffer embedded-buffer) (set-buffer embedded-buffer) (setq buffer-read-only nil) (call-process “program-ﬂash.sh” nil embedded-buffer t) RESOURCES Wine – www.winehq.org/ VirtualBox – www.virtualbox.org/ Eclipse – www.eclipse.org/ Emacs – www.gnu.org/software/emacs/ Cscope – cscope.sourceforge.net/ Busybox – busybox.net/ GDB – www.gnu.org/software/gdb/ DDD – www.gnu.org/software/ddd/ Insight – sourceware.org/insight/ OProﬁle – oproﬁle.sourceforge.net/ 32 APRIL 2008 | embedded systems design europe | www.embedded.com/europe 028-029-030-031-032_ESDE.indd 32 8/04/08 12:41:44 http://oprofile.sourceforge.net/doc/index.html http://oprofile.sourceforge.net/doc/index.html http://www.opersys.com/LTT/dox/ltt-online-help/index.html http://www.opersys.com/LTT/dox/ltt-online-help/index.html http://www.winehq.org/ http://www.virtualbox.org/ http://www.eclipse.org/ http://www.gnu.org/software/emacs/ http://cscope.sourceforge.net/ http://busybox.net/ http://www.gnu.org/software/gdb/ http://www.gnu.org/software/ddd/ http://sourceware.org/insight/ http://oprofile.sourceforge.net/ http://www.embedded.com/europe

Table of Contents Feed for the Digital Edition of Embedded Systems Design Europe - April 2008

Embedded Systems Design Europe - April 2008 Contents Chip Industry Confronts 'Software' Gap Wind River's VxWorks OS Part of the nEUROn UCAV Demonstrator iSuppli Cuts Electronic Equipment Forecast Study Says GigE Vision Not Mature Chip Aids Wireless Health Monitoring Kontron Reports Strong Financial Growth Xilinx Completes Virtex-5 Line-Up French Project Builds Open Platform Home Automation Group Uses Enocean Radio Layer MIPs Adds Multi-Core Option to Portfolio Cover Feature: Next Gen Programmable Chips: Why Can't Hardware Be More Like Software? Improving Productivity & Quality With Domain-Specific Modeling Efficient CRC Calculation With Minimal Memory Footprint Do-It-Yourself Linux Embedded Development Tools Hardware/Software Verification Enters the Atomic Age New Products Advertising Contacts

Embedded Systems Design Europe - April 2008

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