Ukulinganisa iLinus Torvalds: Yenza eyakho inkqubo yokusebenza ukusuka ekuqaleni (VI)

Ewe, emva kobuzali obuncinci siyaqhubeka nothotho lwezifundo zethu. Ukuba sibuyela kwikhowudi yangaphambili kufuneka sibe ne-ISR yokwahlula ngo-zero. Ngoku kufuneka sigcwalise ezinye ii-ISRs esasizithumele (ezokuqala ezingama-32). Ewe ngoku siza kuqhubeka nokuphazamiseka kwenkqubo, siza kwenza i-IRQ eyaziwa ngokuba yi Ukuphazamisa iZicelo. Ezi IRQs ziveliswa zizixhobo zehardware ezinjengebhodi yezitshixo, iimpuku, iiprinta, njl. Ekuqaleni ii-IRQs ezisi-8 zokuqala zenzelwa imephu ngokuzenzekelayo kwizikhundla ze-IDT 8 ukuya ku-15. Njengokuba sisebenzise ezingama-32 zokuqala ngaphandle ngoku kufuneka sizibuyise. Siza kubeka i-IRQ ukusuka kuma-32 kuye kuma-45. Ngoku kufuneka siqale sibuyisele i-IRQs:

void ND::IRQ::Remap(int pic1, int pic2)
{
#define PIC1 0x20
#define PIC2 0xA0
#define ICW1 0x11
#define ICW4 0x01
/* send ICW1 */
ND::Ports::OutputB(PIC1, ICW1);
ND::Ports::OutputB(PIC2, ICW1);
/* send ICW2 */
ND::Ports::OutputB(PIC1 + 1, pic1); /* remap */
ND::Ports::OutputB(PIC2 + 1, pic2); /* pics */
/* send ICW3 */
ND::Ports::OutputB(PIC1 + 1, 4); /* IRQ2 -> connection to slave */
ND::Ports::OutputB(PIC2 + 1, 2);
/* send ICW4 */
ND::Ports::OutputB(PIC1 + 1, ICW4);
ND::Ports::OutputB(PIC2 + 1, ICW4);
/* disable all IRQs */
ND::Ports::OutputB(PIC1 + 1, 0xFF);
}

Ngoku senza umsebenzi wokufaka ii-IRQs:

void ND::IRQ::Install()
{
ND::Screen::SetColor(ND_SIDE_FOREGROUND,ND_COLOR_BLACK);
ND::Screen::PutString("\nInstalling IRQ...");
ND::IRQ::Remap(0x20,0x28);
ND::IDT::SetGate(32,(unsigned)ND::IRQ::IRQ1,0x08,0x8E);
ND::IDT::SetGate(33,(unsigned)ND::IRQ::IRQ2,0x08,0x8E);
ND::IDT::SetGate(34,(unsigned)ND::IRQ::IRQ3,0x08,0x8E);
ND::IDT::SetGate(35,(unsigned)ND::IRQ::IRQ4,0x08,0x8E);
ND::IDT::SetGate(36,(unsigned)ND::IRQ::IRQ5,0x08,0x8E);
ND::IDT::SetGate(37,(unsigned)ND::IRQ::IRQ6,0x08,0x8E);
ND::IDT::SetGate(38,(unsigned)ND::IRQ::IRQ7,0x08,0x8E);
ND::IDT::SetGate(39,(unsigned)ND::IRQ::IRQ8,0x08,0x8E);
ND::IDT::SetGate(40,(unsigned)ND::IRQ::IRQ9,0x08,0x8E);
ND::IDT::SetGate(41,(unsigned)ND::IRQ::IRQ10,0x08,0x8E);
ND::IDT::SetGate(42,(unsigned)ND::IRQ::IRQ11,0x08,0x8E);
ND::IDT::SetGate(43,(unsigned)ND::IRQ::IRQ12,0x08,0x8E);
ND::IDT::SetGate(44,(unsigned)ND::IRQ::IRQ13,0x08,0x8E);
ND::IDT::SetGate(45,(unsigned)ND::IRQ::IRQ14,0x08,0x8E);
ND::IDT::SetGate(46,(unsigned)ND::IRQ::IRQ15,0x08,0x8E);
ND::IDT::SetGate(47,(unsigned)ND::IRQ::IRQ16,0x08,0x8E);
ND::Screen::SetColor(ND_SIDE_FOREGROUND,ND_COLOR_GREEN);
ND::Screen::PutString("done");
asm volatile("sti");
}

Isivakalisi se-asm Sti senza ii-IRQs zisebenze. Ewe ngoku sihamba nento efana ne-ISR. Imisebenzi ye-IRQ esisiseko:

void ND::IRQ::IRQ1()
{
asm volatile(
"cli \n"
"pushl 0\n"
"pushl 32\n"
"jmp ND_IRQ_Common"
);
}


Icandelo eliqhelekileyo (elifanayo ne-ISR):

extern "C"
void ND_IRQ_Common()
{
asm volatile(
"pusha \n"
"push %ds\n"
"push %es\n"
"push %fs\n"
"push %gs\n"
"movw $0x10, %ax \n"
"movw %ax, %ds \n"
"movw %ax, %es \n"
"movw %ax, %fs \n"
"movw %ax, %gs \n"
"movl %esp, %eax \n"
"push %eax \n"
"movl $ND_IRQ_Handler, %eax \n"
"call *%eax \n"
"popl %eax \n"
"popl %ds \n"
"popl %es \n"
"popl %fs \n"
"popl %gs \n"
"popa \n"
"addl 8, %esp \n"
"iret \n"
);
}


Kwaye isiphatho esisiseko:

extern "C"
void ND_IRQ_Handler(struct regs* r)
{
void (*handler)(struct regs *r);
if(r->int_no >= 40)
{
ND::Ports::OutputB(0xA0,0x20);
}
ND::Ports::OutputB(0x20,0x20);
}


Ngale nto kufanele ukuba sele sine-IRQ esebenzayo nokuba ayenzi kwanto. Kwisahluko esilandelayo siza kubona ukuba sifumana njani idatha kwezi IRQ ezifana newotshi okanye ikhibhodi.

Kwaye oku kuyaphela iposti yanamhlanje. Njengoko ubona ngoku ndibhala kancinci rhoqo ngenxa yeminye imiba. Nangona kunjalo ndiza kuqhubeka de ndibenenkqubo yokusebenza epheleleyo