Facebook yakaburitsa zviitiko zvine chekuita nekugadzirwa kwePCIe bhodhi, iyo inosanganisira kuitwa kwediki atomu wachi uye GNSS inogamuchira. Iyo bhodhi inogona kushandiswa kuronga kushanda kweakaparadzana nguva yekuyananisa maseva. Izvo zvinotsanangurwa, schematics, BOM, Gerber, PCB uye CAD mafaera anodiwa kugadzira bhodhi anoburitswa paGitHub. Bhodhi racho rakatanga kugadzirwa sechigadzirwa chemodular, chichibvumira kushandiswa kwezvimwe zvakasiyana-siyana zve-atomic clock chips uye GNSS modules, zvakadai seSA5X, mRO-50, SA.45s uye u-blox RCB-F9T. Orolia inotarisira kutanga kugadzirwa kwemabhodhi akapera zvichibva pane zvakagadzirirwa zvakatemwa.
Iyo Kadhi Yenguva iri kuvandudzwa sechikamu cheimwe yepasirese Nguva Yekushandisa purojekiti, ine chinangwa chekupa zvikamu zvekugadzira ekutanga (Nguva Master) chaiyo nguva maseva (Open Time Server), iyo inogona kuiswa muzvivakwa zvavo uye kushandiswa, semuenzaniso, ronga kuwiriranisa nguva munzvimbo dze data. Kushandisa sevha yakaparadzana kunobvumira kuti usatsamira kune ekunze network masevhisi ekuenzanisa nguva chaiyo, uye kuvapo kweatomu yewachi yakavakirwa-mukati kunopa yakakwira mwero wekuzvimiririra kana paine kutadza kugamuchira data kubva kune satellite masisitimu (semuenzaniso, kumamiriro ekunze kana kurwiswa).
Iyo yakasarudzika yepurojekiti ndeyekuvaka yekutanga chaiyo nguva sevha, unogona kushandisa yakajairwa sevha yakavakirwa pa x86 yekuvaka, kusanganisira yakajairika network kadhi uye Nguva Kadhi. Mune sevha yakadaro, ruzivo pamusoro penguva chaiyo inogamuchirwa kubva kuma satellites kuburikidza neGNSS, uye atomic clock inoshanda seyo oscillator yakagadzikana, ichibvumira kuchengetedza yakakwirira yehutano kana chiitiko chekukundikana mukugamuchira ruzivo kuburikidza neGNSS. Iko kutsauka kunobvira kubva panguva chaiyo kana zvisingakwanisi kuwana data kuburikidza neGNSS mubhodhi rakarongwa inofungidzirwa kusvika ku300 nanoseconds pazuva.
Iyo ocp_pt mutyairi akagadzirirwa Linux uye yakarongwa kuti ibatanidzwe mune huru Linux 5.15 kernel. Mutyairi anoshandisa interfaces PTP POSIX (/dev/ptp2), GNSS kuburikidza ne serial port (/dev/ttyS7), atomic wachi kuburikidza ne serial port (/dev/ttyS8) uye maviri i2c zvishandiso (/dev/i2c-*), uchishandisa iyo inogona kupa mukana kune kugona kweiyo hardware wachi (PHC) kubva kunharaunda yemushandisi. Paunenge uchimhanyisa sevha yeNTP (Network Time Protocol), inokurudzirwa kushandisa Chrony neNTPd, uye kana uchimhanyisa PTP (Precision Time Protocol) server, ptp4u kana ptp4l pamwe chete ne phc2sys stack, iyo inova nechokwadi chekuti nguva dzakakosha dziripo. kukopwa kubva paatomic wachi kuenda kunetiweki kadhi.
Kurongeka kwekushanda kweGNSS inogamuchira uye wachi yeatomu inogona kuitwa muhardware uye software. Kushanda kwehardware yemodule yekufananidza kunoitwa pahwaro hweFPGA, uye shanduro yesoftware inoshanda pamwero wekutarisa kwakananga mamiriro eiyo GNSS inogamuchira uye maatomu wachi kubva kumashandisirwo akaita septp4l uye chronyd.
Chikonzero chekugadzira bhodhi rakavhurika pachinzvimbo chekushandisa yakagadzirira-yakagadzirwa mhinduro dziripo pamusika ndeye proprietary yemhando yezvigadzirwa zvakadaro, izvo zvisingabvumidze munhu kuti aone chokwadi chekushandiswa, kusateedzera kwesoftware yakarongwa ine zvinodiwa zvekuchengetedza. (munguva zhinji, zvirongwa zvechinyakare zvinopihwa, uye kuendeswa kwezvigadziriso zvenjodzi zvinogona kutora mwedzi kana makore), pamwe nekugona kushomeka kwekutarisa (SNMP) uye kumisikidzwa (vanopa yavo CLI kana Webhu UI).
Source: opennet.ru