{"id":38908,"date":"2019-10-31T22:26:41","date_gmt":"2019-10-31T19:26:41","guid":{"rendered":"https:\/\/prohoster.info\/blog\/budushhee-uzhe-zdes-ili-kodim-pryamo-v-brauzere\/"},"modified":"2019-10-31T22:26:41","modified_gmt":"2019-10-31T19:26:41","slug":"budushhee-uzhe-zdes-ili-kodim-pryamo-v-brauzere","status":"publish","type":"post","link":"https:\/\/prohoster.info\/cs\/blog\/administrirovanie\/budushhee-uzhe-zdes-ili-kodim-pryamo-v-brauzere","title":{"rendered":"Budoucnost je ji\u017e zde, nebo k\u00f3dujeme p\u0159\u00edmo v prohl\u00ed\u017ee\u010di","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Pov\u00edm v\u00e1m o kuri\u00f3zn\u00ed situaci, kter\u00e1 se mi stala, a o tom, jak se st\u00e1t p\u0159isp\u011bvatelem do zn\u00e1m\u00e9ho projektu.
\n<\/a><\/noindex>
\nNed\u00e1vno jsem pracoval na jednom n\u00e1padu: spou\u0161t\u011bn\u00ed Linuxu p\u0159\u00edmo z UEFI\u2026
\nN\u00e1pad nen\u00ed nov\u00fd a existuje n\u011bkolik n\u00e1vod\u016f na toto t\u00e9ma. Jeden z nich si m\u016f\u017eete prohl\u00e9dnout tady<\/a><\/noindex><\/p>\n

Moje dlouholet\u00e9 pokusy vy\u0159e\u0161it tuto ot\u00e1zku se vyvinuly v pom\u011brn\u011b podrobn\u00fd rozhodnut\u00ed<\/a><\/noindex>. \u0158e\u0161en\u00ed je pln\u011b funk\u010dn\u00ed a pou\u017e\u00edv\u00e1m ho na n\u011bkter\u00fdch sv\u00fdch dom\u00e1c\u00edch stroj\u00edch. O n\u011bco podrobn\u011bji je toto \u0159e\u0161en\u00ed pops\u00e1no tady<\/a><\/noindex>.<\/p>\n

Podstata UEFI-Boot spo\u010d\u00edv\u00e1 v tom, \u017ee ESP (EFI System Partition) je slou\u010den s adres\u00e1\u0159em \/boot. Tedy, v\u0161echny j\u00e1dra a obrazy po\u010d\u00e1te\u010dn\u00edho zav\u00e1d\u011bn\u00ed (initrd) jsou um\u00edst\u011bny na tomt\u00e9\u017e odd\u00edlu, ze kter\u00e9ho m\u016f\u017ee UEFI spou\u0161t\u011bt spustiteln\u00e9 soubory a konkr\u00e9tn\u011b spou\u0161t\u011bt zav\u00e1d\u011b\u010de syst\u00e9mu. Ale samotn\u00e9 j\u00e1dro Linuxu se ji\u017e v mnoha distribuc\u00edch sestavuje s mo\u017enost\u00ed UEFISTUB, kter\u00e1 umo\u017e\u0148uje j\u00e1dru spustit se z UEFI.<\/p>\n

Toto \u0159e\u0161en\u00ed m\u00e1 jeden nep\u0159\u00edjemn\u00fd moment \u2014 odd\u00edl ESP je form\u00e1tov\u00e1n ve FAT32, na kter\u00e9m nelze vytv\u00e1\u0159et tvrd\u00e9 odkazy (kter\u00e9 syst\u00e9m pravideln\u011b vytv\u00e1\u0159\u00ed p\u0159i aktualizaci initrd). A na tom nen\u00ed nic zvl\u00e1\u0161\u0165 krimin\u00e1ln\u00edho, ale vid\u011bt varov\u00e1n\u00ed syst\u00e9mu p\u0159i aktualizaci komponent j\u00e1dra \u2014 nen\u00ed moc p\u0159\u00edjemn\u00e9\u2026<\/p>\n

Existuje i jin\u00e1 cesta. <\/p>\n

Spr\u00e1vce zav\u00e1d\u011bn\u00ed UEFI (to je ten, do kter\u00e9ho je t\u0159eba zapsat zav\u00e1d\u011b\u010d OS) um\u00ed krom\u011b zav\u00e1d\u011b\u010d\u016f\/jader Linuxu tak\u00e9 na\u010d\u00edtat ovlada\u010de. Tak\u017ee m\u016f\u017eete na\u010d\u00edst ovlada\u010d t\u00e9 souborov\u00e9 soustavy, kde m\u00e1te \/boot, a p\u0159\u00edmo odtud na\u010d\u00edtat j\u00e1dro pomoc\u00ed UEFI. Ovlada\u010d je samoz\u0159ejm\u011b nutn\u00e9 um\u00edstit do odd\u00edlu ESP. P\u0159esn\u011b t\u00edm se zab\u00fdvaj\u00ed zav\u00e1d\u011b\u010de typu GRUB. Ale specialitou je, \u017ee v\u0161echny \u010dasto pou\u017e\u00edvan\u00e9 funkce GRUB ji\u017e existuj\u00ed v UEFI. P\u0159esn\u011bji \u0159e\u010deno v jeho spr\u00e1vcovsk\u00e9m rozhran\u00ed. A pokud bychom cht\u011bli b\u00fdt je\u0161t\u011b \u0161kolometsk\u00fd, spr\u00e1va zav\u00e1d\u011bn\u00ed UEFI m\u00e1 v n\u011bkter\u00fdch ohledech dokonce v\u00edce mo\u017enost\u00ed. <\/p>\n

Zd\u00e1lo by se, \u017ee je to p\u011bkn\u00e9 \u0159e\u0161en\u00ed, ale je tu jedno \u201eALE\u201c (l\u00e9pe \u0159e\u010deno, bylo, ale o tom pozd\u011bji). Jde o to, \u017ee syst\u00e9m ovlada\u010d\u016f UEFI je pom\u011brn\u011b jednoduch\u00fd. Neexistuje zde koncept, jako je p\u0159ipojen\u00ed souborov\u00e9ho syst\u00e9mu nebo p\u0159i\u0159azen\u00ed ovlada\u010de k ur\u010dit\u00e9mu za\u0159\u00edzen\u00ed. Existuje syst\u00e9mov\u00fd vol\u00e1n\u00ed s podm\u00edn\u011bn\u00fdm n\u00e1zvem Map, kter\u00e9 vezme postupn\u011b ka\u017ed\u00fd ovlada\u010d a pokus\u00ed se jej spojit se v\u0161emi vhodn\u00fdmi za\u0159\u00edzen\u00edmi. A pokud se ovlada\u010di poda\u0159\u00ed se za\u0159\u00edzen\u00ed p\u0159ipojit, vytvo\u0159\u00ed se mapov\u00e1n\u00ed \u2014 spojovac\u00ed z\u00e1znam. Pr\u00e1v\u011b tak by m\u011bl b\u00fdt znovu na\u010dten\u00fd ovlada\u010d inicializov\u00e1n mezi ostatn\u00edmi. A je pot\u0159eba ud\u011blat jen to \u2014 v z\u00e1znamu ovlada\u010de nastavit jeden bit (LOAD_OPTION_FORCE_RECONNECT) na 1 a UEFI po jeho na\u010dten\u00ed provede toto glob\u00e1ln\u00ed p\u0159e-mapov\u00e1n\u00ed.<\/p>\n

Jen\u017ee ud\u011blat to nen\u00ed tak jednoduch\u00e9. Standardn\u00ed n\u00e1stroj efibootmgr (kter\u00fd se pou\u017e\u00edv\u00e1 pro konfiguraci UEFI boot manageru) to neum\u00ed (p\u0159esn\u011bji to neum\u011bl) tento bit nastavit. Bylo pot\u0159eba to dod\u011blat ru\u010dn\u011b prost\u0159ednictv\u00edm docela slo\u017eit\u00e9 a riskantn\u00ed procedury. <\/p>\n

A tak p\u0159i dal\u0161\u00edm pokusu ud\u011blat to ru\u010dn\u011b jsem to nevydr\u017eel a vytvo\u0159il jsem issue na GitHubu<\/a><\/noindex> s \u017e\u00e1dost\u00ed k v\u00fdvoj\u00e1\u0159\u016fm, aby tuto mo\u017enost p\u0159idali.<\/p>\n

Uplynulo p\u00e1r dn\u00ed, ale nikdo si m\u00e9 \u017e\u00e1dosti nev\u0161iml. A ze zv\u011bdavosti jsem se pod\u00edval na zdrojov\u00e9 k\u00f3dy\u2026 fork jsem a pak jsem si vymyslel, jak tuto funkci p\u0159idat\u2026 \u201eNa kolen\u011b\u201c, proto\u017ee jsem si nic takov\u00e9ho nenainstaloval a p\u0159\u00edmo v prohl\u00ed\u017ee\u010di jsem editoval zdrojov\u00e9 k\u00f3dy.<\/p>\n

C (programovac\u00ed jazyk) zn\u00e1m velmi povrchn\u011b, ale p\u0159ibli\u017en\u00e9 \u0159e\u0161en\u00ed jsem nakreslil (p\u0159ev\u00e1\u017en\u011b kop\u00edrov\u00e1n\u00edm a vkl\u00e1d\u00e1n\u00edm)\u2026 no a potom jsem si pomyslel \u2014 a\u0165 u\u017e tam m\u00e1m jist\u011b spoustu chyb (moje p\u0159edchoz\u00ed pokusy upravit ciz\u00ed C-k\u00f3d se skl\u00e1daly asi z 10 pokus\u016f), tak jsem vytvo\u0159il Pull Request. A nakonec jsem vytvo\u0159il<\/a><\/noindex>.<\/p>\n

A tam se uk\u00e1zalo, \u017ee je p\u0159ipojen Travis CI na kontrolu pull request\u016f. A ten mi pe\u010dliv\u011b vypsal v\u0161echny moje chyby. No, kdy\u017e jsou chyby zn\u00e1m\u00e9 \u2014 pro\u010d je neopravit: op\u011bt p\u0159\u00edmo v prohl\u00ed\u017ee\u010di, a na \u010dtvrt\u00fd pokus se k\u00f3d sestavil (\u00fasp\u011bch pro m\u011b).<\/p>\n

A takto, ani\u017e bych opustil prohl\u00ed\u017ee\u010d, jsem vytvo\u0159il zcela re\u00e1ln\u00fd Pull Request do n\u00e1stroje, kter\u00fd pou\u017e\u00edv\u00e1 prakticky ve v\u0161ech modern\u00edch distribuc\u00edch Linuxu.<\/p>\n

I was surprised that I, not really knowing the language, without configuring anything on my own (there's quite a hefty stack of libraries needed for assembly), and without even running the compiler once, simply 'coded' a completely functional and useful feature in the browser.<\/p>\n

However, my request remained unanswered since March 19, 2019, and I had already started to forget about it. <\/p>\n

But just yesterday, this request was added to master. <\/p>\n

\nSo what is my story about? It's about how, with modern technologies, it has turned out that real code can already be written in the browser without setting up any local developer tools and dependencies.<\/p>\n

Moreover, I must admit, this is already my second pull request to well-known (at least in narrow circles) utilities. Last time, my request to fix the display of some fields in the web interface of SyncThing resulted in a literally one-line fix in an environment I didn't know at all.<\/p>\n

Pouze registrovan\u00ed u\u017eivatel\u00e9 se mohou \u00fa\u010dastnit ankety. P\u0159ihlaste se<\/a><\/noindex>, pros\u00edm.<\/p>\n

Should I write more or not?<\/h2>\n