An actual memory implementation

app/CMakeLists.txt

@@ -9,7 +9,8 @@ include_directories(${source_DIR}/include)
 add_library(lightswitch SHARED
         ${source_DIR}/lightswitch.cpp
         ${source_DIR}/core/arm/cpu.cpp
+        ${source_DIR}/core/arm/memory.cpp
 
         ${source_DIR}/core/hos/loaders/nro.cpp
 )
-target_link_libraries(lightswitch ${source_DIR}/lib/${ANDROID_ABI}/libunicorn.a)
+target_link_libraries(lightswitch ${source_DIR}/lib/${ANDROID_ABI}/libunicorn.a)

app/src/main/cpp/core/arm/memory.cpp

@@ -0,0 +1,43 @@
+#include <sys/mman.h>
+#include <syslog.h>
+#include <vector>
+#include "memory.h"
+
+std::vector<mem::MemoryRegion> memRegions;
+
+namespace mem {
+    bool Map(uc_engine* uc, uint64_t address, size_t size, std::string label) {
+        void* ptr = mmap((void*)(address), size, PROT_EXEC | PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, 0, 0);
+        if(!ptr)
+            return false;
+
+        // Skipping this until the CPU implementation is working
+        if(uc) {
+            uc_err err = uc_mem_map_ptr(uc, address, size, UC_PROT_ALL, ptr);
+            if(err)
+            {
+                syslog(LOG_ERR, "Memory map failed: %s", uc_strerror(err));
+                return false;
+            }
+        }
+
+        syslog(LOG_INFO, "Successfully mapped region '%s' to 0x%x", label.c_str(), address);
+
+        memRegions.push_back({label, address, size, ptr});
+
+        return true;
+    }
+
+    // TODO: Boundary checks
+    void Write(void* data, uint64_t offset, size_t size) { std::memcpy((void*)(offset), data, size); }
+    void WriteU8(uint8_t value, uint64_t offset)   { Write(reinterpret_cast<void*>(&value), offset, 1); }
+    void WriteU16(uint16_t value, uint64_t offset) { Write(reinterpret_cast<void*>(&value), offset, 2); }
+    void WriteU32(uint32_t value, uint64_t offset) { Write(reinterpret_cast<void*>(&value), offset, 4); }
+    void WriteU64(uint64_t value, uint64_t offset) { Write(reinterpret_cast<void*>(&value), offset, 8); }
+
+    void Read(void* destination, uint64_t offset, size_t size) { std::memcpy(destination, (void*)(offset), size); }
+    uint8_t ReadU8(uint64_t offset)  { uint8_t value; Read(reinterpret_cast<void*>(&value), offset, 1); return value; }
+    uint16_t ReadU16(uint64_t offset) { uint16_t value; Read(reinterpret_cast<void*>(&value), offset, 2); return value; }
+    uint32_t ReadU32(uint64_t offset) { uint32_t value; Read(reinterpret_cast<void*>(&value), offset, 4); return value; }
+    uint64_t ReadU64(uint64_t offset) { uint64_t value; Read(reinterpret_cast<void*>(&value), offset, 8); return value; }
+}

app/src/main/cpp/core/arm/memory.h

@@ -0,0 +1,28 @@
+#pragma once
+#include <string>
+#include <unicorn/unicorn.h>
+
+#define MEM_BASE 0x80000000
+
+namespace mem {
+    struct MemoryRegion {
+        std::string label;
+        uint64_t address;
+        size_t size;
+        void* ptr;
+    };
+
+    bool Map(uc_engine* uc, uint64_t address, size_t size, std::string label="");
+
+    void Write(void* data, uint64_t offset, size_t size);
+    void WriteU8(uint8_t value, uint64_t offset);
+    void WriteU16(uint16_t value, uint64_t offset);
+    void WriteU32(uint32_t value, uint64_t offset);
+    void WriteU64(uint64_t value, uint64_t offset);
+
+    void Read(void* destination, uint64_t offset, size_t size);
+    uint8_t ReadU8(uint64_t offset);
+    uint16_t ReadU16(uint64_t offset);
+    uint32_t ReadU32(uint64_t offset);
+    uint64_t ReadU64(uint64_t offset);
+}

app/src/main/cpp/core/hos/loaders/nro.cpp

@@ -1,13 +1,10 @@
 #include <fstream>
-#include <string>
 #include <syslog.h>
 #include <sys/mman.h>
 #include <vector>
+#include "../../arm/memory.h"
 #include "nro.h"
 
-// TODO: Move memory to it's own file
-#define MEM_BASE 0x80000000
-
 void ReadDataFromFile(std::string file, char* output, uint32_t offset, size_t size)
 {
     std::ifstream f(file, std::ios::binary | std::ios::beg);
@@ -34,30 +31,22 @@ namespace loader {
         ro.resize(h.segments[1].size);
         data.resize(h.segments[2].size);
 
-        ReadDataFromFile(file, reinterpret_cast<char *>(text.data()),
-                                     h.segments[0].fileOffset, h.segments[0].size);
-        ReadDataFromFile(file, reinterpret_cast<char *>(ro.data()),
-                                     h.segments[1].fileOffset, h.segments[1].size);
-        ReadDataFromFile(file, reinterpret_cast<char *>(data.data()),
-                                     h.segments[2].fileOffset, h.segments[2].size);
+        ReadDataFromFile(file, reinterpret_cast<char *>(text.data()), h.segments[0].fileOffset, h.segments[0].size);
+        ReadDataFromFile(file, reinterpret_cast<char *>(ro.data()), h.segments[1].fileOffset, h.segments[1].size);
+        ReadDataFromFile(file, reinterpret_cast<char *>(data.data()), h.segments[2].fileOffset, h.segments[2].size);
 
-
-        if(!mmap((void*)(MEM_BASE),
-                 h.segments[0].size, PROT_EXEC | PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, 0, 0) ||
-           !mmap((void*)(MEM_BASE + h.segments[0].size),
-                 h.segments[1].size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, 0, 0) ||
-           !mmap((void*)(MEM_BASE + h.segments[0].size + h.segments[1].size),
-                 h.segments[2].size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, 0, 0) ||
-           !mmap((void*)(MEM_BASE + h.segments[0].size + h.segments[1].size + h.segments[2].size),
-                 h.bssSize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, 0, 0)) {
+        if( !mem::Map(nullptr, MEM_BASE, h.segments[0].size, ".text") ||
+            !mem::Map(nullptr, MEM_BASE + h.segments[0].size, h.segments[1].size, ".ro") ||
+            !mem::Map(nullptr, MEM_BASE + h.segments[0].size + h.segments[1].size, h.segments[2].size, ".data") ||
+            !mem::Map(nullptr, MEM_BASE + h.segments[0].size + h.segments[1].size + h.segments[2].size, h.bssSize, ".bss")) {
 
            syslog(LOG_ERR, "Failed mapping regions for executable");
            return false;
         }
 
-        std::memcpy((void*)(MEM_BASE), text.data(), text.size());
-        std::memcpy((void*)(MEM_BASE + h.segments[0].size), ro.data(), ro.size());
-        std::memcpy((void*)(MEM_BASE + h.segments[0].size + h.segments[1].size), data.data(), data.size());
+        mem::Write(text.data(), MEM_BASE, text.size());
+        mem::Write(ro.data(), MEM_BASE + h.segments[0].size, ro.size());
+        mem::Write(data.data(), MEM_BASE + h.segments[0].size + h.segments[1].size, data.size());
 
         return true;
     }