'embarcado' Category

  • set
    06
    2010

    Compiler for Nuttx

    I was following this thread on Nuttx maillist on recommended compiler to build Nuttx RTOS. As a matter of practicality I guess that many users use CodeSourcery arm-none-linux-gnueabi but today I decided test the code generated for Cortex-M3 (LPC1768) using the toolchain from Buildroot. As Greg Nutt said (text adapted):
    They were configured using OABI [old arm ABI], but [...]

    posted in embarcado by Tiago Maluta

  • jun
    24
    2010

    Opcode stats

    I was trying some GCC options and decided see how they affect assembly code generated. I’ve created a simple Python script that parses .s output and put in a human readable way. Suppose the classical Hello World program. The output will be something like:
    $ python stats_opcodes.py file
    For Cortex-m3 (check previous post):

    At my laptop (x86):

    Download the script here.

    posted in embarcado by Tiago Maluta

  • jun
    23
    2010

    Cortex-M3 and Qemu

    Just a small tip to test code generated for ARM Cortex-M3 using QEmu:
    $ arm-none-eabi-gcc main.c -ggdb -mcpu=cortex-m3 -mthumb -T generic-m-hosted.ld
    $ qemu-arm -cpu cortex-m3 ./a.out
    You can download Code Sourcery toolchain here and QEmu here (also available from package management system of your favorite Linux distribution). Just unpack the toolchain associating the arm-201XqX/bin with your $PATH and run qemu.

    posted in embarcado by Tiago Maluta

  • jun
    08
    2010

    NFS errors

    If you use NFS to mount your root filesystem you should probably faced with this problem:
    Root-NFS: Unable to get mountd port number from server, using default
    Root-NFS: Server returned error -5 while mounting /my/nfs/server/path/
    VFS: Unable to mount root fs via NFS, trying floppy.
    The -5 and -13 are the most common on my daily usage, but I [...]

    posted in embarcado by Tiago Maluta

  • abr
    12
    2010

    MyHDL: trazendo o Python para o mundo das FPGAs

    From Python to silicon
    Depois de uma longa história estou participando de dois um curso aberto sobre hardware: um abordando VHDL e outro Verilog. Até aí nada de novo, quando… descobri algo interessante. Algo que realmente motivou a mudar minha rotina de trabalho para (durante alguns dias) levantar as 7h. a escrever sobre o assunto aqui [...]

    posted in embarcado by Tiago Maluta

  • abr
    06
    2010

    Stellaris EKK-LM3S9b96 Evaluation Kit (1)

    O blog do Jê foi um dos canais brasileiros que anunciou o concurso promovido pela Texas Instruments e a revista Circuit Cellar. Como sempre tive curiosidade nos microcontroladores de 32bits da ARM resolvi me inscrever no concurso para receber o KIT. Com uma proposta semelhante (mas sem o concurso) a NXP, a um tempo atrás, [...]

    posted in embarcado by Tiago Maluta

  • mar
    09
    2010

    Welcome back NGW100!

    A some time ago I’ve bricked my NGW100 board by overwritten the U-boot from flash. To fix it was necessary using a JTAG interface, so I check some alternatives.

    AVR JTAGICE mkII (US$ 299) [official] http://atmel.com/dyn/products/tools_card.asp?tool_id=3353
    AVR JTAG ICE mkii CN (US$ 99)  http://enshop.avrvi.com/avrjtagicemkiicn.html
    AT AVR JTAGICE mkII clone (US$ 159) http://enshop.avrvi.com/jtagicemkiiclone.html

    Considering that NGW100 itself costs about US$ [...]

    posted in embarcado by Tiago Maluta

  • fev
    24
    2010

    ipconfig over usb ethernet

    I guess this post apply only if you are using Linux v.2.6.33-rc3 or above.
    You would have noted that kernel IP auto-configuration is not usable for some USB-Ethenet dongles on newer kernel because it starts before the USB devices are found. This was already discussed on LKML.  I proposed a workaround adding a section on menuconfig [...]

    posted in embarcado by Tiago Maluta