soaplin/kernel/src/acpi/acpi.c

74 lines
No EOL
1.8 KiB
C
Executable file

/*
* The Soaplin Kernel
* Copyright (C) 2025 The SILD Project
*
* acpi.c - ACPI table lookup
*/
#include <stdbool.h>
#include <acpi/acpi.h>
#include <arch/cpu.h>
#include <boot/limine.h>
#include <lib/log.h>
#include <mm/memop.h>
#include <mm/pmm.h>
#include <stdint.h>
static bool __acpi_use_xsdt;
static uint64_t __acpi_rsdt_addr;
void *acpi_find_table(char *sign) {
if (__acpi_use_xsdt) {
acpi_xsdt_t *xsdt = (acpi_xsdt_t*)__acpi_rsdt_addr;
uint32_t entries = (xsdt->hdr.len - sizeof(xsdt->hdr)) / 8;
for (uint32_t i = 0; i < entries; i++)
{
acpi_sdt_hdr_t *h = (acpi_sdt_hdr_t *)higher_half(*((uint64_t*)xsdt->entries + i));
if (!memcmp(h->sign, sign, 4))
return (void *) h;
}
return NULL;
}
acpi_rsdt_t *rsdt = (acpi_rsdt_t*)__acpi_rsdt_addr;
int entries = (rsdt->hdr.len - sizeof(rsdt->hdr)) / 4;
uint32_t *entries_hhalf = (uint32_t *)higher_half((uint64_t)rsdt->entries);
for (int i = 0; i < entries; i++)
{
acpi_sdt_hdr_t *h = (acpi_sdt_hdr_t *)(entries_hhalf[i] + (i * sizeof(uint32_t)));
if (!memcmp(h->sign, sign, 4))
return (void *) h;
}
return NULL;
}
void acpi_init() {
acpi_rsdp_t *rsdp = (acpi_rsdp_t*)limine_get_rsdp();
if (memcmp(rsdp->sign, "RSD PTR ", 8))
{
fatal("acpi: ACPI RSDP is corrupt\n");
hcf();
}
if (rsdp->rev >= 2)
{
trace("acpi: ACPI v2.0 or later detected: Using XSDT.\n");
acpi_xsdp_t *xsdp = (acpi_xsdp_t *)rsdp;
__acpi_use_xsdt = 1;
__acpi_rsdt_addr = higher_half(xsdp->xsdt_addr);
goto initialized;
}
__acpi_use_xsdt = 0;
__acpi_rsdt_addr = higher_half(rsdp->rsdt_addr); // Do not use a pointer, to shut up the compiler.
initialized:
trace("acpi: Initialized!\n");
}