From 672e2b2d77941b61dfaf753f80afae90241ee080 Mon Sep 17 00:00:00 2001
From: georgemoralis <giorgosmrls@gmail.com>
Date: Thu, 8 Jun 2023 12:51:11 +0300
Subject: [PATCH] initial dynamic loader , parsing DT_HASH atm

---
 src/Core/PS4/Linker.cpp | 19 +++++++++++++++++++
 src/Core/PS4/Linker.h   |  9 +++++++++
 src/Loader/Elf.h        | 13 +++++++++++++
 3 files changed, 41 insertions(+)

diff --git a/src/Core/PS4/Linker.cpp b/src/Core/PS4/Linker.cpp
index 0cc7e646..8476bdbb 100644
--- a/src/Core/PS4/Linker.cpp
+++ b/src/Core/PS4/Linker.cpp
@@ -47,6 +47,7 @@ Module* Linker::LoadModule(const std::string& elf_name)
 	if (m->elf->isElfFile())
 	{
 		LoadModuleToMemory(m);
+		LoadDynamicInfo(m);
 	}
 	else
 	{
@@ -157,4 +158,22 @@ void Linker::LoadModuleToMemory(Module* m)
 		offset += instruction.info.length;
 		runtime_address += instruction.info.length;
 	}
+}
+
+void Linker::LoadDynamicInfo(Module* m)
+{
+	m->dynamic_info = new DynamicModuleInfo;
+
+	for (const auto* dyn = static_cast<elf_dynamic*>(m->m_dynamic); dyn->d_tag != DT_NULL; dyn++)
+	{
+		switch (dyn->d_tag)
+		{
+		case DT_OS_HASH:
+			m->dynamic_info->hash_table = reinterpret_cast<void*>(static_cast<uint8_t*>(m->m_dynamic_data) + dyn->d_un.d_ptr);
+			break;
+		default:
+			LOG_INFO_IF(debug_loader, "unsupported dynamic tag ..........: {:#018x}\n", dyn->d_tag);
+		}
+		
+	}
 }
\ No newline at end of file
diff --git a/src/Core/PS4/Linker.h b/src/Core/PS4/Linker.h
index 002dc30f..7add71c2 100644
--- a/src/Core/PS4/Linker.h
+++ b/src/Core/PS4/Linker.h
@@ -2,6 +2,8 @@
 #include "../../Loader/Elf.h"
 #include <vector>
 
+struct DynamicModuleInfo;
+
 /*this struct keeps neccesary info about loaded modules.Main executeable is included too as well*/
 struct Module
 {
@@ -11,6 +13,12 @@ struct Module
 
 	void* m_dynamic = nullptr;
 	void* m_dynamic_data = nullptr;
+	DynamicModuleInfo* dynamic_info = nullptr;
+};
+
+struct DynamicModuleInfo
+{
+	void* hash_table = nullptr;
 };
 
 class Linker
@@ -22,6 +30,7 @@ public:
 	Module* LoadModule(const std::string& elf_name);
 	Module* FindModule(/*u32 id*/);
 	void LoadModuleToMemory(Module* m);
+	void LoadDynamicInfo(Module* program);
 
 private:
 	std::vector<Module*> m_modules;
diff --git a/src/Loader/Elf.h b/src/Loader/Elf.h
index dbe7c9c3..b425e794 100644
--- a/src/Loader/Elf.h
+++ b/src/Loader/Elf.h
@@ -323,6 +323,19 @@ struct elf_program_id_header
     u64 firmver;
     u08 digest[32];
 };
+
+constexpr s64 DT_NULL = 0;
+constexpr s64 DT_OS_HASH = 0x61000025;
+
+struct elf_dynamic 
+{
+    s64 d_tag;
+    union
+    {
+        u64 d_val;
+        u64 d_ptr;
+    } d_un;
+};
 class Elf
 {
 public: