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feat/kernel: Started on LAPIC

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This commit is contained in:
Kevin Alavik 2025-05-30 11:05:07 +02:00
parent 242ab03274
commit 4534f1da14
Signed by: cmpsb
GPG key ID: 10D1CC0526FDC6D7
5 changed files with 63 additions and 1 deletions
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42
kernel/src/sys/apic/lapic.c Normal file
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/* EMK 1.0 Copyright (c) 2025 Piraterna */
#include <sys/apic/lapic.h>
#include <arch/cpu.h>
#include <sys/acpi/madt.h>
#include <util/log.h>
#include <mm/vmm.h>
#include <boot/emk.h>
uint64_t lapic_msr = 0;
volatile uint64_t *lapic_base = 0;
void lapic_write(uint32_t offset, uint32_t value)
{
if (!lapic_base)
{
log_early("warning: LAPIC not initialized!");
return;
}
volatile uint32_t *reg = (volatile uint32_t *)((uint8_t *)lapic_base + offset);
*reg = value;
}
uint32_t lapic_read(uint32_t offset)
{
if (!lapic_base)
{
log_early("warning: LAPIC not initialized!");
return 0;
}
volatile uint32_t *reg = (volatile uint32_t *)((uint8_t *)lapic_base + offset);
uint32_t value = *reg;
return value;
}
void lapic_init()
{
lapic_msr = rdmsr(LAPIC_BASE);
lapic_base = (volatile uint64_t *)(lapic_msr & ~(0xffff));
/* Change the lapic address that we got from MADT earlier */
lapic_addr = (uint64_t)lapic_base;
log_early("New LAPIC base: 0x%lx", lapic_base);
}