From 7b4bd3577a31d0f0adc7371840642791ae1567f4 Mon Sep 17 00:00:00 2001
From: Amlal <amlal.elmahrouss@icloud.com>
Date: Fri, 24 Jan 2025 10:38:36 +0100
Subject: ADD: Open version, with important changes kept out.

Signed-off-by: Amlal <amlal.elmahrouss@icloud.com>
---
 dev/Kernel/src/ACPIFactoryInterface.cc | 96 ++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 dev/Kernel/src/ACPIFactoryInterface.cc

(limited to 'dev/Kernel/src/ACPIFactoryInterface.cc')

diff --git a/dev/Kernel/src/ACPIFactoryInterface.cc b/dev/Kernel/src/ACPIFactoryInterface.cc
new file mode 100644
index 00000000..cbfded4e
--- /dev/null
+++ b/dev/Kernel/src/ACPIFactoryInterface.cc
@@ -0,0 +1,96 @@
+/* -------------------------------------------
+
+	Copyright (C) 2024, Amlal EL Mahrouss, all rights reserved.
+
+------------------------------------------- */
+
+#include <Mod/ACPI/ACPIFactoryInterface.h>
+#include <NewKit/KString.h>
+#include <ArchKit/ArchKit.h>
+#include <KernelKit/Heap.h>
+
+namespace Kernel
+{
+	/// @brief Finds a descriptor table inside ACPI XSDT.
+	ErrorOr<voidPtr> ACPIFactoryInterface::Find(const Char* signature)
+	{
+		MUST_PASS(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;
+
+		kcout << "ACPI: Number of entries: " << number(this->fEntries) << endl;
+		kcout << "ACPI: Revision: " << number(xsdt->Revision) << endl;
+		kcout << "ACPI: Signature: " << xsdt->Signature << endl;
+		kcout << "ACPI: Address of XSDT: " << hex_number((UIntPtr)xsdt) << endl;
+
+		const short cAcpiSignatureLength = 4;
+
+		for (Size index = 0; index < this->fEntries; ++index)
+		{
+			SDT* sdt = reinterpret_cast<SDT*>(xsdt->AddressArr[index]);
+
+			kcout << "ACPI: Checksum: " << number(sdt->Checksum) << endl;
+			kcout << "ACPI: Revision: " << number(sdt->Revision) << endl;
+
+			for (short signature_index = 0; signature_index < cAcpiSignatureLength; ++signature_index)
+			{
+				if (sdt->Signature[signature_index] != signature[signature_index])
+					break;
+
+				if (signature_index == (cAcpiSignatureLength - 1))
+				{
+					kcout << "ACPI: SDT Signature: " << sdt->Signature << endl;
+					kcout << "ACPI: SDT OEM ID: " << sdt->OemId << endl;
+					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;
+	}
+} // namespace Kernel
-- 
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