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Kernel/VM探検隊@北陸 Part 7 で発表した内容です。

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1. KOBA789 ࣌ͷྲྀΕ͕ڐͤͳ͍ ,FSOFM7.୳ݕୂ!๺཮
   1BSU
   
2. KOBA789 ప໷Ͱͭ͘͹͔ΒंͰདྷ·ͨ͠ʢ৸ෆ଍ʣ w ࢓ࣄͷ࿩͸͠·ͤΜ
   w ࢓ࣄͷ࿩͸͠·ͤΜʢʣ
   w ͏͔ͬΓձࣾͷ1$Λ͖࣋ͬͯͨͷͰ͍ͭ΋ͷࣗݾ঺հςϯϓϨʔτ͕ͳ͍
4. ಈ͘Α͏ʹͳΓ·ͨ͠ ΫϦελϧͷཪ໘ʹ৴߸ઢ͕௨ͬͯͯΫϩοΫ͕๫Ε͍ͯͨͷ͕ݪҼ
5. ࣌ͷྲྀΕ͕ڐͤͳ͍
6. Έͳ͞Μ΋ͦ͏Ͱ͢Ͷʁ
7. ࢲͩͬͯͦ͏ͩ
8. ͭͷϚΠίϯͰ࣌ࠁΛಉظ͍ͨ͠ ΈΜͳେ޷͖6"35ͰλΠϜελϯϓΛૹΔ .$6
   # .$6
   " l
   z
9. ͭͷϚΠίϯͰ࣌ࠁΛಉظ͍ͨ͠ ΈΜͳେ޷͖6"35ͰλΠϜελϯϓΛૹΔ #ͷ࣌ܭ͕ͪΐͬͱ͚ͩ஗ΕΔ .$6
   # .$6
   " l
   z
10. ͭͷϚΠίϯͰ࣌ࠁΛಉظ͍ͨ͠ ΈΜͳେ޷͖6"35ͰλΠϜελϯϓΛૹΔ #ͷ࣌ܭ͕ͪΐͬͱ͚ͩ஗ΕΔ .$6
    # .$6
    " l
    z ͳ͔ͥʁ
11. 6"35ͷ࢓૊Έ CBVEͳΒ#ZUFૹΔͷʹ໿NT͔͔Δ https://vanhunteradams.com/Protocols/UART/UART.html    <CJU>
    
    <CJUT>
    ˺
    <NT> ੨͍෦෼͸KOBA789ʹΑΔՃච
12. 6"35ͷ࢓૊Έ #ZUFͷ࣌ࠁΛૹͬͨΒ໿NT஗Ԇ͢Δ .$6
    # .$6
    " ໿NT #ͷ࣌ܭ͕NT஗ΕΔ   
13. 6"35ͷ࢓૊Έ #ZUFͷ࣌ࠁΛૹͬͨΒ໿NT஗Ԇ͢Δ .$6
    # .$6
    " ໿NT #ͷ࣌ܭ͕NT஗ΕΔ    NT
    Ҿ͍ͨΒʁ
14. ·͊஗Ԇ͕ίϯελϯτͳΒ
    ͦΕͰ͍͍ΜͰ͢Α
15. ͕ͩࣄଶ͸ͦ͏୯७Ͱ͸ͳ͍
16. let time = gettimeofday(); send(time);
17. let time = gettimeofday(); send(time); ߦ໨͕࣮ߦ͞Ε͔ͯΒ
    ߦ໨͕࣮ߦ͞ΕΔ·Ͱͷ஗Ԇ͸ʁ
18. ߦ໨ͱߦ໨ͷؒʹ͋Δ஗Ԇ Α͋͘Γ͕ͪͳϚΠίϯͷ৔߹ w ී௨ʹ໋ྩ࣮ߦʹ͔͔ΔαΠΫϧ෼͚ͩ஗Ԇ͢Δ
    w ༏ઌ౓ͷߴׂ͍ΓࠐΈ͕ೖΕ͹஗Ԇ͢ΔʢཁΫϦςΟΧϧηΫγϣϯʣ
    w ࠷ۙͷϚΠίϯͰ͸
    w $16͕଎͍͗ͯ͢Ζ͍Ζ͕૬ରతʹ஗͍ͷͰΩϟογϡ͕͋Δ
    w Ωϟογϡώοτ
    PS
    OPU
    Ͱ஗Ԇ͕࣌ؒมԽʢඇܾఆ࿦తʣ
    w 5$.ͱ͔࢖͑͹Ϛγʹ͸ͳΔ͕
    w 0VUPG0SEFS࣮ߦ͢Δ
    w ίʔυಡΉ͚ͩͰ͸஗Ԇ͕࣌ؒΘ͔Βͳ͍ʢࣄ্࣮ඇܾఆ࿦తʣ
19. let time = gettimeofday(); send(time);
20. let time = gettimeofday(); send(time); ͦ΋ͦ΋TFOE ͷ࣮૷͸ʁ
21. Α͋͘Δ6"35ૹ৴ϖϦϑΣϥϧʢงғؾʣ ૹ৴'*'0 5%3 ͕ϝϞϦϚοϓ͞Ε͍ۭͯͯʹͳΔͱׂΓࠐΈ͕ೖΔ 4IJGU
    SFHJTUFS EFQUI
    '*'0 59 %"5" όε $16 %"5" '*'0
    &NQUZ
    *OUFSSVQU 5%3
22. 5%3ʹ஋Λॻ͖ࠐΉͱૹ৴͞ΕΔ ͨͱ͑͹5%3ͷΞυϨεΛY@ͱ͢Δ *(uint32_t*)0x400001000 = 'A'; core::ptr::write_volatile(0x400001000 as *mut u8, b'A');
23. 5%3ʹ஋Λॻ͖ࠐΉͱૹ৴͞ΕΔ EFQUI
    '*'0ͳΒจࣈ·Ͱ͸Ұؾʹॻ͚Δ͕ɺӽ͑ΔͱᷓΕΔ core::ptr::write_volatile(0x40000100 as *mut u8, b'0'); core::ptr::write_volatile(0x40000100 as *mut u8, b'1'); core::ptr::write_volatile(0x40000100 as *mut u8, b'2'); core::ptr::write_volatile(0x40000100 as *mut u8, b'3'); core::ptr::write_volatile(0x40000100 as *mut u8, b'4'); core::ptr::write_volatile(0x40000100 as *mut u8, b'5'); core::ptr::write_volatile(0x40000100 as *mut u8, b'6'); core::ptr::write_volatile(0x40000100 as *mut u8, b'7'); core::ptr::write_volatile(0x40000100 as *mut u8, b'8'); core::ptr::write_volatile(0x40000100 as *mut u8, b'9'); core::ptr::write_volatile(0x40000100 as *mut u8, b'A'); core::ptr::write_volatile(0x40000100 as *mut u8, b'B'); core::ptr::write_volatile(0x40000100 as *mut u8, b'C'); core::ptr::write_volatile(0x40000100 as *mut u8, b'D'); core::ptr::write_volatile(0x40000100 as *mut u8, b'E'); core::ptr::write_volatile(0x40000100 as *mut u8, b’F'); // ͔͜͜Βઌ͸ᷓΕΔ
24. Α͋͘Δ6"35υϥΠόʢงғؾʣ %."ͷ͜ͱ͸Ұ୴๨Ε͍ͯͩ͘͞ w TFOE 
    w ·ͣ'*'0ͷۭ͖༰ྔ෼͚ͩॻ͘
    w ᷓΕͨ෼͸ιϑτ΢ΣΞόοϑΝʹॻ͘
    w &NQUZ
    '*'0ׂΓࠐΈ
    w '*'0ͷۭ͖༰ྔ෼͚ͩιϑτ΢ΣΞόοϑΝ͔ΒҠ͢
25. ΋͏͓෼͔ΓͰ͢Ͷʁ
26. όοϑΝɾ'*'0͕
    ٧·ͬͯͨΒ
    ଈ࠲ʹ͸ૹ৴͞Εͳ͍
    ʢͦΕ͸ͦ͏ʣ
27. ͯ͞
28. Α͋͘Δ6"35ड৴ϖϦϑΣϥϧʢงғؾʣ ड৴'*'0 3%3 ͕ϝϞϦϚοϓ͞Ε͍ͯͯ஋͕དྷΔͱׂΓࠐΈ͕ೖΔ 4IJGU
    SFHJTUFS EFQUI
    '*'0 39 %"5" όε $16 %"5" '*'0
    /PO&NQUZ
    *OUFSSVQU 3%3
29. 3%3͔Β஋ΛಡΉͱ'*'0͔ΒQPQ͞ΕΔ ͨͱ͑͹3%3ͷΞυϨεΛY@ͱ͢Δ uint8_t r = *(uint32_t*)0x40000200; // r == 'A' let r = core::ptr::read_volatile(0x40000100 as *const u8); // r == b’A'
30. Α͋͘Δ6"35υϥΠόʢงғؾʣ %."ͷ͜ͱ͸Ұ୴๨Ε͍ͯͩ͘͞ʢʣ w /POFNQUZ
    '*'0ׂΓࠐΈ
    w '*'0ͷ಺༰Λιϑτ΢ΣΞόοϑΝʹҠ͢
    w ͜ΕΛ͠ͳ͍ͱ'*'0͸༰қʹᷓΕΔ
    w SFDW 
    w ιϑτ΢ΣΞόοϑΝ͔ΒಡΈग़͢
31. ड৴σʔλͷಡΈऔΓ͸͍͘ΒͰ΋஗Ԇ͢Δ ΋͏͓Θ͔ΓͰ͢Ͷʢʣ w ΞϓϦέʔγϣϯ͕ιϑτ΢ΣΞόοϑΝΛ͍ͭಡΉ͔͸ࣗ༝
    w ׂΓࠐΈϋϯυϥ͕ݺ͹ΕΔλΠϛϯά͸ʜʜʁ
    w ΞςʹͳΒͳ͍
    w ผͷΫϦςΟΧϧηΫγϣϯͰεϐϯϩοΫͯͨ͠Β஗ΕΔ
    w $PSUFY.Ͱ͸ׂΓࠐΈͷԣऔΓͱ͔ͰϨΠςϯγ͕ζϨΔ
32. ࠔΔ
33. ࠔΔͷͰɺΑ͋͘Δํ๏ʢ6"35 114ʣ ඵ͝ͱʹύϧεΛೖྗ͠ɺͦΕΛϋʔυ΢ΣΞͰΩϟϓνϟ͢Δ .$6
    # .$6
    " l
    z ʮࠓͰ͢ʂʯ
34. *OQVU
    $BQUVSF0VUQVU
    $PNQBSF ΠέͯΔϚΠίϯͷλΠϚʹ͸͍͍ͩͨ͋Δ w *OQVU
    $BQUVSF
    w ύϧεೖྗΛτϦΨʔʹͯ͠ɺΧ΢ϯλͷ஋ΛϨδελʹΩϟϓνϟ
    w ιϑτ΢ΣΞͷλΠϛϯάʹґଘͤͣਖ਼֬ͳλΠϛϯά͕औΕΔ
    w (1*0ׂΓࠐΈͱ͸શ͘ผͷػೳ
    w 0VUQVU
    $PNQBSF
    w Χ΢ϯλͷ஋ΛτϦΨʔʹͯ͠ɺύϧεΛग़ྗ
    w ιϑτ΢ΣΞͷλΠϛϯάʹґଘͤͣʢSZ
35. ΊͰͨ͠ΊͰͨ͠ʢʁʣ
36. ݪཧతʹ͸੒ཱ͍ͯ͠Δ͕ݱ࣮తʹ͸ࠔΔ 6"35͸࣌ࠁ഑৴ઐ༻Ͱ͸ͳ͍ɻଞͷίϚϯυ΋ૹΓ͍ͨ .$6
    # .$6
    " l
    z ʮࠓͰ͢ʂʯ $.%@%0@40.&5)*/( ࠞͬͯ͟͠·͏
37. 6"35ʹྲྀΕΔσʔλΛ෼ผ͍ͨ͠ ͜ͷ΁ΜͷεϥΠυ͕Ͱ͖ͯͳ͍ w σʔλΛ෼ผ͢Δʹ͸ϔομΛ෇͚Δͷ͕ৗ౟खஈ
    w ϔομΛ෇͚Δʹ͸ύέοτࢦ޲͡Όͳ͍ͱ͍͚ͳ͍
    w ͱ͜ΖͰ6"35͸ͨͩͷ੾Ε໨ͷͳ͍όΠτετϦʔϜ
    w ύέοτʹ͢Δʹ͸ϓϩτίϧ͕ඞཁ
    w ͔͠΋ඪ४Խ͞Εͯͳ͍ͱඍਖ΋خ͘͠ͳ͍
38. ͜ͷ΁ΜͷεϥΠυ͕Ͱ͖ͯͳ͍
39. ΋͏݁࿦ߦͧ͘
40. 151 1SFDJTJPO
    5JNF
    1SPUPDPM &UIFSOFU্Ͱ/51ΑΓਫ਼ີͳ࣌ࠁಉظΛ͢Δϓϩτίϧ w ൃ૝ͱͯ͠͸/51ͱಉ͡ʢԟ෮ͰϨΠςϯγΛଌΔʣ
    w େ͖ͳҧ͍͸ϋʔυ΢ΣΞλΠϜελϯϓͷαϙʔτ
    w &UIFSOFUϑϨʔϜͷ4'%͕1):Λ௨աͨ͠ॠؒͷΧ΢ϯλͷ஋Λ
    ϋʔυ΢ΣΞͰΩϟϓνϟ͢Δ
    w ΑΓਫ਼ີʹϨΠςϯγ͕ଌΕΔͷͰVTʙOTΦʔμʔͷਫ਼౓͕ૂ͑Δ
    w ࣮ࡍʹ͸΋ͬͱ͍Ζ͍Ζ͋Δ͕ɺ͜͜ʹॻ͘ʹ͸४උ͕࣌ؒ଍Βͳ͗͢͞Δ
41. 151 1SFDJTJPO
    5JNF
    1SPUPDPM &UIFSOFU্Ͱ/51ΑΓਫ਼ີͳ࣌ࠁಉظΛ͢Δϓϩτίϧ .$6
    # .$6
    "
42. 31J
    $.ͱळ݄ͷ(14ϞδϡʔϧͰ࡞ΕΔ ͜ͷهࣄಡΜͩΒ؆୯ʹ࡞ΕΔͱࢥ͏ https://www.je ff geerling.com/blog/2022/ptp-and-ieee-1588-hardware-timestamping-on-raspberry-pi-cm4
43. /VDMFP 45. Ͱ΋΍Ε͹ಈ͘ ୭΋151ͳΜͯ࢖ͬͯͳ͍ͷͰؾ߹ೖΕ࣮ͯ૷͢Δඞཁ͸͋Δ
44. ͱͳΔͱؾʹͳΔ͜ͱ͕
    ͋Γ·͢Ͷʁ
45. Ϣʔβʔϥϯυͷ"1*
    Ͳ͏ͳͬͯΜͩ
46. #4%
    TPDLFUʹ
    λΠϜελϯϓऔΔ"1*͸ͳ͍
47. ·ͣ͸TFUTPDLPQUͰઃఆ͢Δ https://docs.kernel.org/networking/timestamping.html#so-timestamping-also-so-timestamping-old-and-so-timestamping-new
48. ·ͣ͸TFUTPDLPQUͰઃఆ͢Δ https://docs.kernel.org/networking/timestamping.html#so-timestamping-also-so-timestamping-old-and-so-timestamping-new
49. ·ͣ͸TFUTPDLPQUͰઃఆ͢Δ https://docs.kernel.org/networking/timestamping.html#so-timestamping-also-so-timestamping-old-and-so-timestamping-new ΤϥʔΩϡʔʹ
    ใࠂ͞ΕΔ
50. ·ͣ͸TFUTPDLPQUͰઃఆ͢Δ https://docs.kernel.org/networking/timestamping.html#so-timestamping-also-so-timestamping-old-and-so-timestamping-new ͸ʁʁʁ
51. λΠϜελϯϓ͸
    ΠϯλʔϑΣʔεΛ
    ഁյͯͭ͠Β͍
    ʢਫ਼౓ӠʑΑΓͦΕ͕ͭΒ͍ʣ