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Week-3 @RTEMS-GSoC-2025

Published on 11 Jun 2025

Overview

This week is the third week working with RTEMS as a GSoC Contributor. This week wholly lies in the Coding Period of GSoC. This week, I completed the following tasks :

  • Able to start GRETH Simulation in RTEMS-SIS Terminal
  • Continued coding for GRETH lwIP
  • Created Blog post for Week-3

Work completed this week

  1. Able to start simulation of GRETH Legacy Network Driver in RTEMS-SIS, after a long wait.

    • First I started lxcbr0 bridge in one terminal and start SIS in another terminal, ttcpshell01.exe being generated after building RTEMS Net Services. Starting-SIS-terminal-for-LEON3
    • But, I got this error indicating that the network stack is not able to obtain network configuration via BOOTP Protocol and hence the network device (GRETH) is not configured properly. BOOTP_error
    • Also, unexpectedly, no tap interface was automatically created in spite of enabling GRETH. lxcbr0_no_tap
    • So, I decided to go with assigning Static IP to the GRETH Driver. Upon exploring further, I learnt that setting required configuration in config.inc file of RTEMS Net Services then building RTEMS Net Services would set this configuration in hence generated ttcpshell01.exe. In addition, I decided to set configuration for GRETH Driver using custom rtems_bsdnet_ifconfig struct and rtems_bsdnet_config struct; however, on doing this, sometimes I was getting BOOTP error again in some cases, and in some other cases, different types of errors occured, one of them indicating that invalid address is present in a register. Upon checking . instruction_trap_error
    • Lastly, I thought of restarting my approach again so I just set the configuration in config.inc file of RTEMS Net Services and built it, avoiding using custom rtems_bsdnet_ifconfig and rtems_bsdnet_config structs…and…the shell started inside SIS where I was able to run ttcp commands! SIS_TTCP_working
    • tap0 interface was also created successfully when TTCP was running. tap0_interface_created
    • However, apparently the traffic in TTCP was too overwhelming causing it to crash unexpectedly. So, according to the suggestion of my mentors, I am planning too check with Telnet and/or TCP Echo Server, or rather even UDP Echo Server.
  2. Continued coding for GRETH lwIP Port
    • This week, I was not able to devote much time for coding for GRETH lwIP Port
    • However I studied further studied esecially memory mapping for GRETH.
  3. Created Blog post for current week (Week-3)

Plans for next week

  1. Explore options for TCP Echo Server / Telnet / UDP Server for GRETH Legacy Networking Driver Simulation
  2. Create blogs till Week-4 by end of week
  3. Continue on GRETH lwIP Code

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