IPC Episode 1 - Prologue

app/CMakeLists.txt

@@ -12,6 +12,7 @@ add_library(lightswitch SHARED
         ${source_DIR}/core/arm/cpu.cpp
         ${source_DIR}/core/arm/memory.cpp
 
+	${source_DIR}/core/hos/kernel/ipc.cpp
 	${source_DIR}/core/hos/kernel/kernel.cpp
 	${source_DIR}/core/hos/kernel/svc.cpp
         ${source_DIR}/core/hos/loaders/nro.cpp

app/src/main/cpp/core/hos/kernel/ipc.cpp

@@ -0,0 +1,49 @@
+#include <syslog.h>
+#include <cstdlib>
+#include "ipc.h"
+
+namespace core::kernel
+{
+    IpcRequest::IpcRequest(uint8_t* tlsPtr)
+    {
+        for(int i = 0; i < 32; i++)
+            syslog(LOG_DEBUG, "%02x\t%02x %02x %02x %02x %02x %02x %02x %02x", i*8, tlsPtr[0+(i*8)], tlsPtr[1+(i*8)], tlsPtr[2+(i*8)], tlsPtr[3+(i*8)], tlsPtr[4+(i*8)], tlsPtr[5+(i*8)], tlsPtr[6+(i*8)], tlsPtr[7+(i*8)]);
+        syslog(LOG_DEBUG,     "-----------------------");
+        uint32_t word1 = ((uint32_t*)tlsPtr)[1];
+        type = *(uint16_t*)tlsPtr;
+        xCount = tlsPtr[2] & 0xF0 >> 4;
+        aCount = tlsPtr[2] & 0x0F;
+        bCount = tlsPtr[3] & 0xF0 >> 4;
+        wCount = tlsPtr[3] & 0x0F;
+        dataSize = word1 & 0x3FF;
+        dataPos = 8;
+
+        if(tlsPtr[2] || tlsPtr[3])
+        {
+            syslog(LOG_ERR, "IPC - X/A/B/W descriptors");
+            exit(0);
+        }
+
+        syslog(LOG_DEBUG, "Enable handle descriptor: %s", word1 >> 31 ? "yes" : "no");
+        if(word1 >> 31)
+        {
+            syslog(LOG_ERR, "IPC - Handle descriptor");
+            exit(0);
+        }
+
+        // Align to 16 bytes
+        if((dataPos % 16) != 0)
+            dataPos += 16 - (dataPos % 16);
+        dataPtr = &tlsPtr[dataPos+16];
+
+        syslog(LOG_DEBUG, "Type: %x", type);
+        syslog(LOG_DEBUG, "X descriptors: 0x%x", xCount);
+        syslog(LOG_DEBUG, "A descriptors: 0x%x", aCount);
+        syslog(LOG_DEBUG, "B descriptors: 0x%x", bCount);
+        syslog(LOG_DEBUG, "W descriptors: 0x%x", wCount);
+        syslog(LOG_DEBUG, "Raw data size: 0x%x", word1 & 0x3FF);
+        syslog(LOG_DEBUG, "Data offset=%x, Data size=%x", dataPos, dataSize);
+        syslog(LOG_DEBUG, "Payload CmdId=%i", *((uint32_t*)&tlsPtr[dataPos+8]));
+        syslog(LOG_DEBUG, "Setting dataPtr to %08x", dataPos+16);
+    }
+}

app/src/main/cpp/core/hos/kernel/ipc.h

@@ -0,0 +1,31 @@
+#pragma once
+#include <cstdint>
+
+namespace core::kernel
+{
+class IpcRequest
+{
+public:
+    IpcRequest(uint8_t* tlsPtr);
+
+    template<typename T>
+    T GetValue()
+    {
+        dataPos += sizeof(T);
+        return *reinterpret_cast<T*>(&dataPtr[dataPos-sizeof(T)]);
+    }
+
+    uint16_t type, xCount, aCount, bCount, wCount;
+    uint32_t dataSize;
+
+private:
+    uint8_t* dataPtr;
+    uint32_t dataPos;
+};
+
+class IpcResponse
+{
+public:
+    IpcResponse() {}
+};
+}

app/src/main/cpp/core/hos/kernel/kernel.h

@@ -2,6 +2,8 @@
 #include <cstdint>
 #include <memory>
 
+#define SM_HANDLE 0xd000 // sm: is hardcoded for now
+
 namespace core::kernel
 {
     class KObject

app/src/main/cpp/core/hos/kernel/svc.cpp

@@ -4,10 +4,40 @@
 #include <utility>
 #include "core/arm/cpu.h"
 #include "core/arm/memory.h"
+#include "kernel.h"
+#include "ipc.h"
 #include "svc.h"
 
 using namespace core::cpu;
 namespace core::kernel {
+    static uint32_t ConnectToNamedPort()
+    {
+        std::string port(8, '\0');
+        memory::Read((void*)port.data(), GetRegister(UC_ARM64_REG_X1), 8);
+
+        if(std::strcmp(port.c_str(), "sm:") == 0)
+            SetRegister(UC_ARM64_REG_W1, SM_HANDLE);
+        else
+        {
+            syslog(LOG_ERR, "svcConnectToNamedPort tried connecting to invalid port '%s'", port.c_str());
+            exit(0);
+        }
+
+        return 0;
+    }
+
+    static uint32_t SendSyncRequest()
+    {
+        syslog(LOG_INFO, "svcSendSyncRequest called for handle 0x%x, dumping TLS:", GetRegister(UC_ARM64_REG_X0));
+        uint8_t tls[0x100];
+        memory::Read(&tls, 0x2000000, 0x100);
+
+        core::kernel::IpcRequest* r = new core::kernel::IpcRequest(tls);
+
+        exit(0);
+        return 0;
+    }
+
     static uint32_t OutputDebugString()
     {
         std::string debug(GetRegister(UC_ARM64_REG_X1), '\0');
@@ -71,9 +101,9 @@ namespace core::kernel {
             {0x1c, nullptr},
             {0x1d, nullptr},
             {0x1e, nullptr},
-            {0x1f, nullptr},
+            {0x1f, ConnectToNamedPort},
             {0x20, nullptr},
-            {0x21, nullptr},
+            {0x21, SendSyncRequest},
             {0x22, nullptr},
             {0x23, nullptr},
             {0x24, nullptr},