LC3 script tools

LC3 script toolchain based on sources - https://github.com/edga/lc3 commit c7e8222bd74923f02a80986c83197796a725136c

Video instruction

https://vk.com/video-210998646_456239037

Dirs

• /tests: Regress, unit and speed tests.
• /lc3tools: Unix LC3 assembler and simulator from the book accompanying web-site.
• /lcc-1.3: LCC based C compiler for LC3.
• /lc3sim-c: A C implementation of the LC-3 virtual machine, an educational computer architecture.
• /lc3sim_cpp: C++ virtual machine with virtual interfaces

Before compile

Install cmake, compiler and libs (for altlinux):

sudo apt-get install build-environment ctest gcc-c++ flex libncurses-devel

Chages

• Migrate to cmake
• Regress test
• Unit test
• Speed test
• Small bash script for simple use cmake clean_build.bash and rebuild_and_test.bash
• lc3sim_cpp virtual machine
• 32 and 64 bit version
• __asm insertion in C compiler lcc

Usage

Script file

script.c

void some_func(void)
{
    // This code run user operation SimpleOp::Operation with value a_RegValue1 = 10, a_RegValue2 = 11, a_Value = 20
    __asm {
        AND R0, R0, #0
        ADD R0, R0, #10
        AND R1, R1, #0
        ADD R1, R1, #11
        RTI R0, R1, #20
    }
}

int main()
{
    some_func();
    return 0;
}

Compile script

Run lcc compile:

./build/bin/lcc -target=lc3 script.c -o script

lcc generate script.asm and script.obj files

Run script file

Script file script.obj file can load with function LC3_Sim::Processor::LoadObjFile, see example:

#include "lc3sim.h"
#include "os.h"

class SimpleIO: public LC3_Sim::IInputOutput
{
public:
    virtual LC3_Sim::Char GetChar() const override
    {
        return getchar();
    }

    virtual void PutChar(LC3_Sim::Char a_Word) override
    {
        putchar(a_Word);
    }

    virtual LC3_Sim::Bool CheckKeyboard() const override
    {
        return false;
    }
};

class SimpleVM: public LC3_Sim::IVirtualMemory
{
public:
    SimpleVM()
    {
        m_Memory.resize(LC3_MAX_MEMORY_ADDRESS);
    }

    virtual LC3_Sim::IVirtualMemory::Result Read(LC3_Sim::RegType* a_Value, LC3_Sim::AddressType a_Address) const override
    {
        if (a_Address >= LC3_MAX_MEMORY_ADDRESS)
            return rErrorAddressOutOfRange;

        *a_Value = m_Memory[a_Address];
        return rSuccess;
    }

    virtual LC3_Sim::IVirtualMemory::Result Write(LC3_Sim::RegType a_Value, LC3_Sim::AddressType a_Address) override
    {
        if (a_Address >= LC3_MAX_MEMORY_ADDRESS)
            return rErrorAddressOutOfRange;

        m_Memory[a_Address] = a_Value;
        return rSuccess;
    }
private:
    std::vector<LC3_Sim::RegType> m_Memory;
};

class SimpleOp: public LC3_Sim::IReservedOperation
{
public:
    virtual LC3_Sim::I_RTI_Operation::Result Operation(LC3_Sim::RegType a_RegValue1, LC3_Sim::RegType a_RegValue2, LC3_Sim::RegType a_Value) override
    {
        printf("User operation reg1 = %ld reg2 = %ld val = %ld\n", (long int)a_RegValue1, (long int)a_RegValue2, (long int)a_Value);
        return rSuccess;
    }
};

int main(int argc, const char* argv[])
{
    SimpleIO simpleio;
    SimpleVM simplevm;
    SimpleOp simpleop;
    LC3_Sim::Registers reg;

    LC3_Sim::ProcessorConfig config(0, 0xfffe, 0);
    LC3_Sim::Processor proc(&reg, &simplevm, &simpleio, &simpleop, &config);

    LC3_Sim::Processor::LoadResult res = proc.LoadData(lc3os_bin_data, lc3os_bin_data_len);

    if (res == LC3_Sim::Processor::lrSuccess)
        res = proc.LoadObjFile("script.obj");

    LC3_Sim::InstructionIndex instr = 0;
    proc.Run(&instr, 0xFFFF);

    return 0;
}

Use one define in LC3_16BIT, LC3_32BIT, LC3_32BIT_WIDE, LC3_64BIT_WIDE to compile for some architecture.

For more info see:

• unit test /test/unit/lc3sim_cpp/test_lc3sim_cpp_instr_maker.cpp
• lc3sim_cpp /lc3sim_cpp/main.cpp
• regress test /test/regress/__asm_test/test_res.c