From f842a9255fc7226d15d128b7d0a63ec58ee38f45 Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Fri, 13 Oct 2023 11:24:21 +0300
Subject: [PATCH] Kernel: Allow getting ACPI headers with same signature

---
 kernel/include/kernel/ACPI.h |  2 +-
 kernel/kernel/ACPI.cpp       | 13 ++++++++++---
 kernel/kernel/APIC.cpp       |  2 +-
 kernel/kernel/Timer/HPET.cpp |  2 +-
 kernel/kernel/lai_host.cpp   |  3 +--
 5 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/kernel/include/kernel/ACPI.h b/kernel/include/kernel/ACPI.h
index 4937a6af8..69905c221 100644
--- a/kernel/include/kernel/ACPI.h
+++ b/kernel/include/kernel/ACPI.h
@@ -108,7 +108,7 @@ namespace Kernel
 		static BAN::ErrorOr<void> initialize();
 		static ACPI& get();
 
-		const SDTHeader* get_header(const char[4]);
+		const SDTHeader* get_header(BAN::StringView signature, uint32_t index);
 
 	private:
 		ACPI() = default;
diff --git a/kernel/kernel/ACPI.cpp b/kernel/kernel/ACPI.cpp
index ae447ce3e..ab9955866 100644
--- a/kernel/kernel/ACPI.cpp
+++ b/kernel/kernel/ACPI.cpp
@@ -222,13 +222,20 @@ namespace Kernel
 		return {};
 	}
 
-	const ACPI::SDTHeader* ACPI::get_header(const char signature[4])
+	const ACPI::SDTHeader* ACPI::get_header(BAN::StringView signature, uint32_t index)
 	{
+		if (signature.size() != 4)
+		{
+			dprintln("Trying to get ACPI header with {} byte signature ??", signature.size());
+			return nullptr;
+		}
+		uint32_t cnt = 0;
 		for (auto& mapped_header : m_mapped_headers)
 		{
 			auto* header = mapped_header.as_header();
-			if (memcmp(header->signature, signature, 4) == 0)
-				return header;
+			if (memcmp(header->signature, signature.data(), 4) == 0)
+				if (cnt++ == index)
+					return header;
 		}
 		return nullptr;
 	}
diff --git a/kernel/kernel/APIC.cpp b/kernel/kernel/APIC.cpp
index 02cfa9cc4..1af40d70f 100644
--- a/kernel/kernel/APIC.cpp
+++ b/kernel/kernel/APIC.cpp
@@ -95,7 +95,7 @@ namespace Kernel
 			return nullptr;
 		}
 
-		const MADT* madt = (const MADT*)Kernel::ACPI::get().get_header("APIC");
+		const MADT* madt = (const MADT*)Kernel::ACPI::get().get_header("APIC"sv, 0);
 		if (madt == nullptr)
 		{
 			dprintln("Could not find MADT header");
diff --git a/kernel/kernel/Timer/HPET.cpp b/kernel/kernel/Timer/HPET.cpp
index e660b2d88..59089e90d 100644
--- a/kernel/kernel/Timer/HPET.cpp
+++ b/kernel/kernel/Timer/HPET.cpp
@@ -46,7 +46,7 @@ namespace Kernel
 
 	BAN::ErrorOr<void> HPET::initialize(bool force_pic)
 	{
-		auto* header = (ACPI::HPET*)ACPI::get().get_header("HPET");
+		auto* header = (ACPI::HPET*)ACPI::get().get_header("HPET"sv, 0);
 		if (header == nullptr)
 			return BAN::Error::from_errno(ENODEV);
 
diff --git a/kernel/kernel/lai_host.cpp b/kernel/kernel/lai_host.cpp
index 3b3eba9d0..d7b854b2d 100644
--- a/kernel/kernel/lai_host.cpp
+++ b/kernel/kernel/lai_host.cpp
@@ -51,8 +51,7 @@ void laihost_panic(const char* msg)
 
 void* laihost_scan(const char* sig, size_t index)
 {
-	ASSERT(index == 0);
-	return (void*)ACPI::get().get_header(sig);
+	return (void*)ACPI::get().get_header(sig, index);
 }
 
 void* laihost_map(size_t address, size_t count)