From 2d59766eb330b9d15a9bcbcd7e1695809fc099c5 Mon Sep 17 00:00:00 2001 From: EmulatedSeasons <89668582+EmulatedSeasons@users.noreply.github.com> Date: Fri, 3 May 2024 03:39:47 -0400 Subject: renamed i386 to x86 --- kernel/arch/x86/pic.cpp | 97 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 kernel/arch/x86/pic.cpp (limited to 'kernel/arch/x86/pic.cpp') diff --git a/kernel/arch/x86/pic.cpp b/kernel/arch/x86/pic.cpp new file mode 100644 index 0000000..78cbcf8 --- /dev/null +++ b/kernel/arch/x86/pic.cpp @@ -0,0 +1,97 @@ +#include +#include +#include +#include + +#define PIC1 0x20 +#define PIC2 0xA0 +#define PIC1_CMD PIC1 +#define PIC1_DATA (PIC1 + 1) +#define PIC2_CMD PIC2 +#define PIC2_DATA (PIC2 + 1) +#define PIC_READ_IRR 0x0a // OCW3 irq ready next CMD read +#define PIC_READ_ISR 0x0b // OCW3 irq service next CMD read + +#define PIC_EOI 0x20 + +// pic reinitialization constants +#define ICW1_ICW4 0x01 // indicates icw4 will be present +#define ICW1_SINGLE 0x02 // single cascade mode +#define ICW1_INTERVAL4 0x04 // call address interval 4 +#define ICW1_LEVEL 0x08 // level triggered (edge) mode +#define ICW1_INIT 0x10 // initialization + +#define ICW4_8086 0x01 // 8086 mode +#define ICW4_AUTO 0x02 // auto (normal) eoi +#define ICW4_BUF_SLAVE 0x08 // buffered mode/slave +#define ICW4_BUF_MASTER 0x0C // buffered mode/master +#define ICW4_SFNM 0x10 // special fully nested (not) + +void pic_send_eoi(unsigned char irq) { + if (irq >= 8) { + outb(PIC2_CMD, PIC_EOI); + } + outb(PIC1_CMD, PIC_EOI); +} + +// offset 1 is for master, offset 2 is for slave +void pic_remap(int offset1, int offset2) { + unsigned char a1, a2; + + a1 = inb(PIC1_DATA); // save masks + a2 = inb(PIC2_DATA); + + outb(PIC1_CMD, ICW1_INIT | ICW1_ICW4); // starts initialization in cascade mode + io_wait(); + outb(PIC2_CMD, ICW1_INIT | ICW1_ICW4); + io_wait(); + outb(PIC1_DATA, offset1); // icw2: master and slave vector offset set + io_wait(); + outb(PIC2_DATA, offset2); + io_wait(); + outb(PIC1_DATA, 4); // tells master pic theres a slave pic at irq2 + io_wait(); + outb(PIC2_DATA, 2); // tells slave pic its cascade identity + io_wait(); + + outb(PIC1_DATA, ICW4_8086); + io_wait(); + outb(PIC2_DATA, ICW4_8086); + io_wait(); + + outb(PIC1_DATA, a1); // restore masks + outb(PIC2_DATA, a2); + + for (char i = 0; i < 15; i++) + { + irq_set_mask(i); + } +} + +void irq_set_mask(unsigned char irq) { + uint16_t port; + uint8_t value; + + if (irq < 8) { + port = PIC1_DATA; + } else { + port = PIC2_DATA; + irq -= 8; + } + value = inb(port) | (1 << irq); + outb(port, value); +} + +void irq_clear_mask(unsigned char irq) { + uint16_t port; + uint8_t value; + + if (irq < 8) { + port = PIC1_DATA; + } else { + port = PIC2_DATA; + irq -= 8; + } + value = inb(port) & ~(1 << irq); + outb(port, value); +} \ No newline at end of file -- cgit v1.2.3-70-g09d2