Kuteedzera Linus Torvalds: gadzira yako yega sisitimu yekushandisa kubva pakutanga (VII)

Kugamuchirwa kune imwe posvo nezve maitiro ekugadzira yedu pachedu sisitimu (Zvinyorwa zvakapfuura munhevedzano: 1, 2, 3, 4, 5 y 6). Yakave iri nguva yakareba kubvira yekupedzisira posvo, kunyanya nekuda kwebug iyo yandakawana mune izvo zvatiinazvo nhasi. Tichaona maitiro ekubata wachi pane x86 mavakirwo.

Pakutanga tanga taita kuti IRQs iitwe nenzira yakajairika, asi pakanga paine dambudziko diki sezvo isu tisina kuvamisa nenzira kwayo uye takapfuudza imwe data. Isu tinozozvigadzirisa carlosorta uye ini neni tinogona kuenderera mberi tichitaura nezvekuenderera mberi.

Zvakanaka, iyo wachi iri IRQ, kunyanya yekutanga. Kuimisa, isu tinoshandisa iro basa ratakatsanangura pamusoro kuti tiise IRQs, iyo ND_IRQ_InstallHandler.

int ND_TIMER_TICKS = 0; void ND :: Nguva: Phase (int hz) {int divisor = 1193180 / hz; ND :: Zviteshi zvengarava: KubudaB (0x43,0x36); ND :: Ports :: KuburitsaB (0x40, divisor & 0xFF); ND :: Ports :: KubudaB (0x40, divisor >> 8); } void ND :: Timer :: Mira (int ticks) {unsigned marefu eticks; eticks = ND_TIMER_TICKS + zvikwekwe; apo (ND_TIMER_TICKS <eticks) {void ND :: Timer :: Setup () {ND :: Screen :: SetColor (ND_SIDE_FOREGROUND, ND_COLOR_BLACK); ND :: Screen :: PutString ("\ nSetup timer ..."); ND_IRQ_InstallHandler (0, & ND_Timer_Handler); ND :: Screen :: SetColor (ND_SIDE_FOREGROUND, ND_COLOR_GREEN); ND :: Screen :: PutString ("zvaitwa"); } extern "C" isina ND_Timer_Handler (struct regs * r) {ND_TIMER_TICKS ++; kana (ND_TIMER_TICKS% 18 == 0) {// ND :: Screen :: SetColor (ND_SIDE_FOREGROUND, ND_COLOR_BROWN); // ND :: Screen :: PutString ("\ nIyezve wechipiri"); TINOFANIRA KUZIVA ZVINONYANYA KUONESA}}

Iyo kodhi inomhanya seinotevera: iyo yekutanga system kufona ND :: Nguva :: Setup, iyo inodaidza ND_IRQ_InstallHandler kuisa munzvimbo yekutanga, iyo IRQ0, yekufona basa kana chiitiko chikaitika, ndiko kuti ND_Timer_Handler izvo zvinowedzera iyo ticks. Sezvo isu takamisikidza kumhanya wachi kusvika ku18 Hz, sezvatichaona gare gare, kana isu tikaipatsanura na18 ndokutipa iyo manhamba, yechipiri ingadai yapfuura.

Basa racho ND :: Nguva :: Chikamu Zvinotibatsira kugadzirisa kumhanya kweiyo timer, iyo yekuwedzeredza nhamba i1.19 .XNUMX MHz inova yakakosha kukosha. Zvakanaka, iri basa rinofanira kudaidzwa kana tichida kuchinja kumhanya kweiyo timer, nekumisikidza inoenda kuna 18,22 Hz, kukosha kwakasarudzika uko mumwe munhu anofanira kunge akasarudza mukati IBM uye ichiripo nanhasi.

Basa racho ND :: Nguva :: Mira zviri nyore, chingomirira uine chiuno apo kusvikira iyo ticks yaida kuenderera.

Mumufananidzo tinogona kuona kuti kana tikabvisa kodhi iri mukati me ND_Timer_Handler tinowana izvi:

Muchitsauko chinotevera tichaona maitiro ekuverenga yekuisa keyboard uye toita zvishoma deko kusangana nehurongwa hwedu. Semazuva ese, kodhi inowanikwa mukati GitHub pasi pezenisi GNU GPL v2.