f1923fdbcf
- Reworked IDT initialization to register all 32 CPU exception handlers (ISR 0-31) and 16 hardware interrupt handlers (IRQ 0-15, mapped to IDT entries 32-47). - Created assembly stubs in interrupts.S using macros for ISRs with and without error codes, plus IRQ stubs. All route through a common stub that saves registers, loads kernel data segment, and calls the C handler. - Added isr.c with a unified interrupt dispatcher that handles both exceptions (halts on fault) and hardware IRQs (sends EOI via PIC). - Implemented PIC (8259) driver in pic.c with full initialization sequence that remaps IRQ 0-7 to IDT 32-39 and IRQ 8-15 to IDT 40-47. Includes mask/unmask and EOI support. - Extracted port I/O primitives (inb, outb, io_wait) into port_io.h header for reuse across drivers. - Kernel now initializes PIC after IDT and enables interrupts with STI.
76 lines
1.8 KiB
C
76 lines
1.8 KiB
C
#include "isr.h"
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#include "pic.h"
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#include <stdint.h>
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/* Forward declaration for kernel panic or similar */
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void offset_print(const char *str);
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void print_hex(uint32_t val);
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/* Exception messages */
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char *exception_messages[] = {
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"Division By Zero",
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"Debug",
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"Non Maskable Interrupt",
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"Breakpoint",
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"Into Detected Overflow",
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"Out of Bounds",
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"Invalid Opcode",
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"No Coprocessor",
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"Double Fault",
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"Coprocessor Segment Overrun",
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"Bad TSS",
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"Segment Not Present",
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"Stack Fault",
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"General Protection Fault",
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"Page Fault",
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"Unknown Interrupt",
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"Coprocessor Fault",
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"Alignment Check",
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"Machine Check",
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"Reserved",
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"Reserved",
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"Reserved",
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"Reserved",
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"Reserved",
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"Reserved",
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"Reserved",
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"Reserved",
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"Reserved",
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"Reserved",
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"Reserved",
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"Reserved",
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"Reserved"
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};
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void isr_handler(registers_t *regs)
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{
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// If it's a hardware interrupt (IRQ), we must acknowledge it
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if (regs->int_no >= 32 && regs->int_no < 48) {
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// Send EOI to PIC (IRQ number 0-15)
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pic_send_eoi(regs->int_no - 32);
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// Here we would call the registered handler for this IRQ
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// For now, just print something for the timer tick so we know it works,
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// but limit it to avoid flooding the log.
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if (regs->int_no == 32) {
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// Timer tick - do nothing verbose
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// offset_print(".");
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} else if (regs->int_no == 33) {
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// Keyboard
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offset_print("Keyboard IRQ!\n");
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}
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return;
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}
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offset_print("received interrupt: ");
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print_hex(regs->int_no);
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offset_print("\n");
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if (regs->int_no < 32)
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{
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offset_print(exception_messages[regs->int_no]);
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offset_print(" Exception. System Halted!\n");
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for (;;) ;
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}
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}
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