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article-tgtimes-what-on-mars.mw - tgtimes - The Gopher Times |
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git clone git://bitreich.org/tgtimes git://enlrupgkhuxnvlhsf6lc3fziv5h2hhfrinws65d7roiv6bfj7d652fid.onion/tgtimes (git://bitreich.org) |
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README |
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article-tgtimes-what-on-mars.mw (2278B) |
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1 .SH tgtimes |
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2 What really happened on Mars? |
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3 .2C 34v |
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4 . |
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5 .PP |
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6 What can possibly go wrong while sending a device entirely controlled |
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7 by software on a remote location where noone would ever be able to |
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8 go for a long while? The question opens a vast field of answers. |
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9 . |
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10 .PP |
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11 1997, Pathfinder, a solar-powered ground lander and station, with |
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12 VxWorks proprietary real time operating system onboard, embedding |
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13 an 6-wheeled Sojourner rover with custom firmware, landed on Mars. |
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14 . |
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15 .PP |
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16 During a field data collection mission a priority inversion did |
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17 happen on the Pathfinder station total loss of control for the time |
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18 of a reboot. |
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19 . |
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20 .PP |
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21 The bug was reproduced on earth and patched, latter explained on a |
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22 mailing list, published online. |
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23 . |
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24 .FS |
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25 https://www.cs.unc.edu/~anderson/teach/comp790/papers/mars_pathfinder_long_version.html |
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26 .FE |
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27 . |
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28 .PP |
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29 At its core, most operating systems are built around a scheduler |
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30 that orchestrates execution of many tasks onto one or several CPUs. |
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31 It is a critical piece of software in the case of real-time operating |
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32 systems, that must ensure to trigger some actions right on time. |
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33 . |
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34 .PP |
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35 Complex systems may be unfit for such purposes, and software |
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36 simplicity has found its way through experimenting how complex |
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37 systems may end-up in difficult-to-debug situations. |
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38 . |
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39 .PP |
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40 Imagine yourself in charge of reproducing a bug on earth for |
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41 something that went wrong on another planet, with a patch expected |
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42 for next Monday. A strong argument toward keeping systems simple |
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43 and easier to debug. |
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44 . |
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45 .PP |
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46 Although, the Mars operating system landscape is not all VxWorks and |
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47 nothing else. For instance, the RTEMS system, Real-Time Executive |
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48 for Multiprocessor Systems was open-sourced from US army 1993 and is |
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49 today actively maintained by both corporations and the open source |
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50 community. |
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51 . |
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52 .PP |
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53 Being part of Google Summer of Code, it is also welcoming newcomers |
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54 to real-time operating system development, who might be able to |
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55 contribute to embedded software making its way onto space. |
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56 . |
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57 .FS |
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58 https://www.rtems.org/ |
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59 .FE |
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60 . |
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61 .PP |
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62 While the ISS project was put at threat by the current events in |
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63 Ukraine involving all nations, outter-space still represents a middle |
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64 ground where all sides have a same objective and can collaborate: |
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65 extending the horizons above what could be reached before. |
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