Merge pull request #8 from rebovas/msr

Msr + interrupts implement + crude implementation of IDT filling

2 files changed, 164 insertions, 0 deletions

diff --git a/arch/x86/msr/Msr.cpp b/arch/x86/msr/Msr.cpp
new file mode 100644
index 0000000..6d21b54
--- /dev/null
+++ b/arch/x86/msr/Msr.cpp
@@ -0,0 +1,106 @@
+#include "Msr.h"
+
+Msr::Msr()
+{
+    Cpuinfo cpuinfo;
+    cpuinfo.cpuid(Cpuinfo::VersionInfo);
+
+    msrSupport = cpuinfo.getRegs().edx & Cpuinfo::MSR;
+};
+
+bool Msr::rdmsr(MsrCommand *cmd)
+{
+    if(!msrSupport or cmd == nullptr) return true;
+
+    uint64 rdmsrResult = 0;
+    uint32 regs[2];
+    asm(
+        "mov %2, %%ecx\n\t"
+        "rdmsr\n\t"
+        "mov %%eax, %0\n\t"
+        "mov %%edx, %1\n\t"
+        : "=&r"(regs[0]), "=&r"(regs[1])
+        : "r"(cmd->getCommand()));
+
+    MemoryOperations::copy(regs, &rdmsrResult, sizeof(uint64));
+    cmd->decode(rdmsrResult);
+
+    return false;
+};
+
+bool Msr::wrmsr(MsrCommand *cmd)
+{
+    if(!msrSupport or cmd == nullptr) return true;
+
+    uint32 regs[2];
+    uint64 msr = cmd->getMsr();
+
+    MemoryOperations::copy(&msr, regs, sizeof(uint64));
+
+    asm(
+        "mov %0, %%eax\n\t"
+        "mov %1, %%edx\n\t"
+        "mov %2, %%ecx\n\t"
+        "wrmsr\n\t"
+        : "=r"(regs[0]), "=r"(regs[1])
+        : "r"(cmd->getCommand()));
+
+    return false;
+};
+
+Ia32ApicBase::Ia32ApicBase()
+{
+    Cpuinfo cpuinfo;
+    bool cpuidAddrSzNotSupport = cpuinfo.cpuid(Cpuinfo::AddressSize);
+    cpuidOutputRegisters AddrSzRegs = cpuinfo.getRegs();
+
+    cpuinfo.cpuid(Cpuinfo::VersionInfo);
+    if(cpuinfo.getRegs().edx & Cpuinfo::PAE
+        and cpuidAddrSzNotSupport) maxPhyAddr = 36;
+    else if(cpuidAddrSzNotSupport) maxPhyAddr = 32;
+    else if(!cpuidAddrSzNotSupport) maxPhyAddr = (uint8)AddrSzRegs.edx;
+
+    bspFlag = enableFlag = false;
+    baseField = NULL;
+};
+
+uint32 Ia32ApicBase::getCommand()
+{
+    return 0x1b;
+};
+
+void Ia32ApicBase::decode(uint64 rdmsrResult)
+{
+    bspFlag = rdmsrResult & BSP_FLAG;
+    enableFlag = rdmsrResult & APIC_ENABLE_FLAG;
+    setBaseField(rdmsrResult);
+};
+
+uint64 Ia32ApicBase::getMsr()
+{
+    uint64 msr = 0;
+
+    MemoryOperations::copy(&baseField, &msr, sizeof(uint64));
+    msr |= bspFlag << 8;
+    msr |= enableFlag << 11;
+
+    return msr;
+};
+
+void Ia32ApicBase::setBaseField(uint64 fieldAddr)
+{
+    uint64 mask = BASE_FIELD_MASK_LOW | 
+                    ((UINT64_HIGH<< (maxPhyAddr - 32)) ^ UINT64_HIGH);
+
+    baseField = fieldAddr & mask;
+};
+
+void Ia32ApicBase::setBspFlag(bool flag)
+{
+    bspFlag = flag;
+};
+
+void Ia32ApicBase::setEnableFlag(bool flag)
+{
+    enableFlag = flag;
+};
diff --git a/arch/x86/msr/Msr.h b/arch/x86/msr/Msr.h
new file mode 100644
index 0000000..98c1b02
--- /dev/null
+++ b/arch/x86/msr/Msr.h
@@ -0,0 +1,58 @@
+// Tasks:
+//         1) Implement msr write and save functions
+//         2) Ia32ApicBase field
+
+#include "../cpuinfo/Cpuinfo.h"
+#include <MemoryOperations.h>
+
+#ifndef MSR_H
+#define MSR_H
+
+// defines for Ia32ApicBase
+
+#define BSP_FLAG 0x100
+#define APIC_ENABLE_FLAG 0x800
+#define BASE_FIELD_MASK_LOW 0xfffff000
+#define UINT64_HIGH 0xffffffff00000000
+
+//------------------------
+
+class MsrCommand
+{
+    public:
+        virtual uint32 getCommand() = 0;
+        virtual void decode(uint64 rdmsrResult) = 0;
+        virtual uint64 getMsr() = 0;
+};
+
+class Ia32ApicBase : public MsrCommand
+{
+    private:
+        // Get through Cpuinfo instance
+        uint8 maxPhyAddr;
+        bool bspFlag, enableFlag;
+        uint64 baseField;
+
+    public:
+        Ia32ApicBase();
+        virtual uint32 getCommand() override final;
+        virtual void decode(uint64 rdmrResult) override final;
+        virtual uint64 getMsr() override final;
+        void setBspFlag(bool flag);
+        void setEnableFlag(bool flag);
+        void setBaseField(uint64 fieldAddr);
+};
+
+class Msr
+{
+    private:
+        bool msrSupport;
+    public:
+        Msr();
+        // Return true if MSR not supported (CPUID.01H:EDX[5] = 0)
+        bool rdmsr(MsrCommand *cmd);
+        // Return value same as rdmsr method
+        bool wrmsr(MsrCommand *cmd);
+};
+
+#endif