From 5f0b15e2fa1aa4dec7f45519ffa55d9c7163d0ff Mon Sep 17 00:00:00 2001
From: georgemoralis <giorgosmrls@gmail.com>
Date: Wed, 17 May 2023 19:29:05 +0300
Subject: [PATCH] draft work on memory allocation

---
 CMakeLists.txt      |  2 +-
 src/Core/Memory.cpp | 50 +++++++++++++++++++++++++++++++++++++++++++++
 src/Core/Memory.h   | 11 ++++++++++
 3 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 src/Core/Memory.cpp
 create mode 100644 src/Core/Memory.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index acdeb680..3b08cb04 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -26,7 +26,7 @@ add_executable(shadps4
     src/Loader/Elf.cpp
     src/Loader/Elf.h
     src/GUI/ElfViewer.cpp
-    src/GUI/ElfViewer.h "src/Util/Log.h" "src/Util/Log.cpp")
+    src/GUI/ElfViewer.h "src/Util/Log.h" "src/Util/Log.cpp" "src/Core/Memory.cpp" "src/Core/Memory.h")
 
 find_package(OpenGL REQUIRED)
 
diff --git a/src/Core/Memory.cpp b/src/Core/Memory.cpp
new file mode 100644
index 00000000..1420f0db
--- /dev/null
+++ b/src/Core/Memory.cpp
@@ -0,0 +1,50 @@
+#include "../Loader/Elf.h"
+#include <windows.h>
+#include "../Util/Log.h"
+
+namespace Memory
+{
+
+	static u64 get_aligned_size(const elf_program_header* phdr)
+	{
+		return (phdr->p_align != 0 ? (phdr->p_memsz + (phdr->p_align - 1)) & ~(phdr->p_align - 1) : phdr->p_memsz);
+	}
+
+	static u64 calculate_base_size(const elf_header* ehdr, const elf_program_header* phdr)
+	{
+		u64 base_size = 0;
+		for (u16 i = 0; i < ehdr->e_phnum; i++)
+		{
+			if (phdr[i].p_memsz != 0 && (phdr[i].p_type == PT_LOAD || phdr[i].p_type == PT_SCE_RELRO))
+			{
+				auto phdrh = phdr + i;
+				u64 last_addr = phdr[i].p_vaddr + get_aligned_size(phdrh);
+				if (last_addr > base_size)
+				{
+					base_size = last_addr;
+				}
+			}
+		}
+		return base_size;
+	}
+
+	namespace VirtualMemory {
+
+		u64 memory_alloc(u64 address, u64 size)
+		{
+			//TODO it supports only execute_read_write mode
+			auto ptr = reinterpret_cast<uintptr_t>(VirtualAlloc(reinterpret_cast<LPVOID>(static_cast<uintptr_t>(address)), 
+															    size,
+																static_cast<DWORD>(MEM_COMMIT) | static_cast<DWORD>(MEM_RESERVE),
+																PAGE_EXECUTE_READWRITE));
+
+			if (ptr == 0)
+			{
+				auto err = static_cast<u32>(GetLastError());
+				LOG_ERROR_IF(true,"VirtualAlloc() failed: 0x{:X}\n", err);
+			}
+			return ptr;
+		}
+	}
+
+}
\ No newline at end of file
diff --git a/src/Core/Memory.h b/src/Core/Memory.h
new file mode 100644
index 00000000..961415c5
--- /dev/null
+++ b/src/Core/Memory.h
@@ -0,0 +1,11 @@
+#pragma once
+
+namespace Memory
+{
+	static u64 get_aligned_size(const elf_program_header* phdr);
+	static u64 calculate_base_size(const elf_header* ehdr, const elf_program_header* phdr);
+
+	namespace VirtualMemory {
+		u64 memory_alloc(u64 address, u64 size);
+	}
+}
\ No newline at end of file