1 files changed, 101 insertions, 0 deletions
diff --git a/dev/kernel/src/ACPIFactoryInterface.cc b/dev/kernel/src/ACPIFactoryInterface.cc
new file mode 100644
index 00000000..3cc76e44
--- /dev/null
+++ b/dev/kernel/src/ACPIFactoryInterface.cc
@@ -0,0 +1,101 @@
+/* -------------------------------------------
+
+	Copyright (C) 2024-2025, Amlal EL Mahrouss, all rights reserved.
+
+------------------------------------------- */
+
+#include <modules/ACPI/ACPIFactoryInterface.h>
+#include <NewKit/KString.h>
+#include <ArchKit/ArchKit.h>
+#include <KernelKit/MemoryMgr.h>
+
+namespace NeOS
+{
+	/// @brief Finds a descriptor table inside ACPI XSDT.
+	ErrorOr<voidPtr> ACPIFactoryInterface::Find(const Char* signature)
+	{
+		MUST_PASS(this->fRsdp);
+
+		if (!signature)
+			return ErrorOr<voidPtr>{-1};
+
+		if (*signature == 0)
+			return ErrorOr<voidPtr>{-1};
+
+		RSDP* rsp_ptr = reinterpret_cast<RSDP*>(this->fRsdp);
+
+		if (rsp_ptr->Revision <= 1)
+			return ErrorOr<voidPtr>{-1};
+
+		RSDT* xsdt = reinterpret_cast<RSDT*>(rsp_ptr->RsdtAddress);
+
+		Int64 num = (xsdt->Length - sizeof(SDT)) / sizeof(Int64);
+
+		/***
+			crucial to avoid underflows.
+		*/
+		if (num < 1)
+		{
+			/// stop here, we should have entries...
+			ke_panic(RUNTIME_CHECK_ACPI);
+			return ErrorOr<voidPtr>{-1};
+		}
+
+		this->fEntries = num;
+
+		kout << "ACPI: Number of entries: " << number(this->fEntries) << kendl;
+		kout << "ACPI: Revision: " << number(xsdt->Revision) << kendl;
+		kout << "ACPI: Signature: " << xsdt->Signature << kendl;
+		kout << "ACPI: Address of XSDT: " << hex_number((UIntPtr)xsdt) << kendl;
+
+		const short cAcpiSignatureLength = 4;
+
+		for (Size index = 0; index < this->fEntries; ++index)
+		{
+			SDT* sdt = reinterpret_cast<SDT*>(xsdt->AddressArr[index]);
+
+			kout << "ACPI: Checksum: " << number(sdt->Checksum) << kendl;
+			kout << "ACPI: Revision: " << number(sdt->Revision) << kendl;
+
+			for (short signature_index = 0; signature_index < cAcpiSignatureLength; ++signature_index)
+			{
+				if (sdt->Signature[signature_index] != signature[signature_index])
+					break;
+
+				if (signature_index == (cAcpiSignatureLength - 1))
+				{
+					kout << "ACPI: SDT Signature: " << sdt->Signature << kendl;
+					kout << "ACPI: SDT OEM ID: " << sdt->OemId << kendl;
+					return ErrorOr<voidPtr>(reinterpret_cast<voidPtr>(xsdt->AddressArr[index]));
+				}
+			}
+		}
+
+		return ErrorOr<voidPtr>{-1};
+	}
+
+	/***
+	@brief Checksum on SDT header.
+	@param checksum the header to checksum
+	@param len the length of it.
+	*/
+	bool ACPIFactoryInterface::Checksum(const Char* checksum, SSizeT len)
+	{
+		if (len == 0)
+			return 1;
+
+		char chr = 0;
+
+		for (int index = 0; index < len; ++index)
+		{
+			chr += checksum[index];
+		}
+
+		return chr == 0;
+	}
+
+	ErrorOr<voidPtr> ACPIFactoryInterface::operator[](const Char* signature)
+	{
+		return this->Find(signature);
+	}
+} // namespace NeOS