From f71a29b6c4779e5401e0122637af3fe4cb543105 Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Tue, 13 Aug 2024 22:38:01 +0300
Subject: [PATCH] Kernel: Implement AliasOp for AML interpreter

---
 kernel/include/kernel/ACPI/AML/Alias.h | 74 ++++++++++++++++++++++++++
 kernel/include/kernel/ACPI/AML/Node.h  |  3 +-
 kernel/kernel/ACPI/AML/Node.cpp        |  3 ++
 3 files changed, 79 insertions(+), 1 deletion(-)
 create mode 100644 kernel/include/kernel/ACPI/AML/Alias.h

diff --git a/kernel/include/kernel/ACPI/AML/Alias.h b/kernel/include/kernel/ACPI/AML/Alias.h
new file mode 100644
index 00000000..61520343
--- /dev/null
+++ b/kernel/include/kernel/ACPI/AML/Alias.h
@@ -0,0 +1,74 @@
+#pragma once
+
+#include <kernel/ACPI/AML/NamedObject.h>
+#include <kernel/ACPI/AML/Names.h>
+#include <kernel/ACPI/AML/ParseContext.h>
+
+namespace Kernel::ACPI::AML
+{
+
+	struct Alias : public AML::NamedObject
+	{
+		BAN::RefPtr<AML::Node> target;
+
+		Alias(NameSeg name, BAN::RefPtr<AML::Node> target)
+			: NamedObject(Node::Type::Alias, name)
+			, target(target)
+		{}
+
+		bool is_scope() const override { return target->is_scope(); }
+
+		BAN::RefPtr<Node> copy() override { return target->copy(); }
+
+		BAN::RefPtr<AML::Buffer> as_buffer() override { return target->as_buffer(); }
+		BAN::RefPtr<AML::Integer> as_integer() override { return target->as_integer(); }
+		BAN::RefPtr<AML::String> as_string() override { return target->as_string(); }
+
+		BAN::RefPtr<AML::Node> evaluate() override { return target->evaluate(); }
+		bool store(BAN::RefPtr<AML::Node> node) override { return target->store(node); }
+
+		static ParseResult parse(ParseContext& context)
+		{
+			ASSERT(context.aml_data.size() >= 1);
+			ASSERT(static_cast<Byte>(context.aml_data[0]) == Byte::AliasOp);
+			context.aml_data = context.aml_data.slice(1);
+
+			auto source_string = AML::NameString::parse(context.aml_data);
+			if (!source_string.has_value())
+				return ParseResult::Failure;
+
+			auto source_object = AML::Namespace::root_namespace()->find_object(context.scope, source_string.value(), AML::Namespace::FindMode::Normal);
+			if (!source_object)
+			{
+				AML_ERROR("Alias target could not be found");
+				return ParseResult::Failure;
+			}
+
+			auto alias_string = AML::NameString::parse(context.aml_data);
+			if (!alias_string.has_value())
+				return ParseResult::Failure;
+
+			auto alias = MUST(BAN::RefPtr<Alias>::create(alias_string.value().path.back(), source_object));
+			if (!Namespace::root_namespace()->add_named_object(context, alias_string.value(), alias))
+				return ParseResult::Success;
+
+	#if AML_DEBUG_LEVEL >= 2
+			alias->debug_print(0);
+			AML_DEBUG_PRINTLN("");
+	#endif
+
+			return ParseResult::Success;
+		}
+
+		void debug_print(int indent) const override
+		{
+			AML_DEBUG_PRINT_INDENT(indent);
+			AML_DEBUG_PRINTLN("Alias {} { ", name);
+			target->debug_print(indent + 1);
+			AML_DEBUG_PRINTLN("");
+			AML_DEBUG_PRINT_INDENT(indent);
+			AML_DEBUG_PRINT("}");
+		}
+	};
+
+}
diff --git a/kernel/include/kernel/ACPI/AML/Node.h b/kernel/include/kernel/ACPI/AML/Node.h
index 2e82f6ed..df451474 100644
--- a/kernel/include/kernel/ACPI/AML/Node.h
+++ b/kernel/include/kernel/ACPI/AML/Node.h
@@ -19,10 +19,11 @@ namespace Kernel::ACPI::AML
 
 		enum class Type
 		{
-			Debug,
+			Alias,
 			BankFieldElement,
 			Buffer,
 			BufferField,
+			Debug,
 			Device,
 			FieldElement,
 			IndexFieldElement,
diff --git a/kernel/kernel/ACPI/AML/Node.cpp b/kernel/kernel/ACPI/AML/Node.cpp
index 288dd764..fb2854ef 100644
--- a/kernel/kernel/ACPI/AML/Node.cpp
+++ b/kernel/kernel/ACPI/AML/Node.cpp
@@ -1,3 +1,4 @@
+#include <kernel/ACPI/AML/Alias.h>
 #include <kernel/ACPI/AML/Buffer.h>
 #include <kernel/ACPI/AML/Bytes.h>
 #include <kernel/ACPI/AML/Device.h>
@@ -165,6 +166,8 @@ namespace Kernel::ACPI
 			case AML::Byte::CreateDWordFieldOp:
 			case AML::Byte::CreateQWordFieldOp:
 				return AML::BufferField::parse(context);
+			case AML::Byte::AliasOp:
+				return AML::Alias::parse(context);
 			case AML::Byte::NameOp:
 				return AML::Name::parse(context);
 			case AML::Byte::PackageOp: