Function FindSDT

Kernel/src/arch/x86_64/acpi.cpp:36–67

	char oem[7];

	void* FindSDT(const char* signature, int index)
	{
		int entries = 0;
		
		if(desc->revision == 2){
			entries = (rsdtHeader->header.length - sizeof(acpi_header_t)) / sizeof(uint64_t); // ACPI 2.0
		} else {
			entries = (rsdtHeader->header.length - sizeof(acpi_header_t)) / sizeof(uint32_t); // ACPI 1.0
		}

		auto getEntry = [](unsigned index) -> uintptr_t { // This will handle differences in ACPI revisions
			if(desc->revision == 2){
				return xsdtHeader->tables[index];
			} else {
				return rsdtHeader->tables[index];
			}
		};

		int _index = 0;

		if(memcmp("DSDT", signature, 4) == 0) return (void*)Memory::GetIOMapping(fadt->dsdt);
	
		for (int i = 0; i < entries; i++)
		{
			acpi_header_t* h = (acpi_header_t*)Memory::GetIOMapping(getEntry(i));
			if (memcmp(h->signature, signature, 4) == 0 && _index++ == index)
				return h;
		}
	
		// No SDT found
		return NULL;
	}

	int ReadMADT(){
		void* madt = FindSDT("APIC", 0);