diff options
| -rw-r--r-- | CMakeLists.txt | 2 | ||||
| -rw-r--r-- | bus.cpp | 46 | ||||
| -rw-r--r-- | bus.hpp | 6 | ||||
| -rw-r--r-- | vdp.cpp | 64 | ||||
| -rw-r--r-- | vdp.hpp | 23 |
5 files changed, 117 insertions, 24 deletions
diff --git a/CMakeLists.txt b/CMakeLists.txt index 0b2323c..5edf23b 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -20,6 +20,7 @@ set(emulator_sources emulator.cpp gdbremote_parser.cpp m68k_debugging.cpp + vdp.cpp ) set(musashi_m68k_sources musashi-m68k/m68kcpu.c @@ -49,6 +50,7 @@ target_link_libraries(emulator musashi_m68k) target_compile_definitions(emulator PRIVATE DEBUG_TRACE_INSTRUCTIONS=0 DEBUG_TRACE_GDB_REMOTE=0 + DEBUG_TRACE_VDP_ACCESS=1 ) ## Target for GDB Remote Debugging protocol implementation testing @@ -4,6 +4,7 @@ #include "bus.hpp" #include "musashi-m68k/m68k.h" #include "utils.hpp" +#include "vdp.hpp" #include <cassert> #include <cstdarg> @@ -12,6 +13,10 @@ #include <cstdint> #include <cstdlib> +#if !defined(DEBUG_TRACE_VDP_ACCESS) +# define DEBUG_TRACE_VDP_ACCESS 0 +#endif + namespace Adr { static constexpr uint32_t kZ80BusReq = 0x00a11100; } @@ -22,9 +27,10 @@ unsigned char g_rom[ROM_SIZE] = {}; unsigned char g_ram[RAM_SIZE] = {}; unsigned char g_sound_ram[SOUND_RAM_SIZE] = {}; unsigned char g_io1[IO1_SIZE] = {}; -unsigned char g_io2[VDP_SIZE] = {}; std::vector<Breakpoint> code_bkpts{}, read_bkpts{}, write_bkpts{}, access_bkpts{}; +static VDP g_vdp(VDP_START); + static void exit_error(const char* fmt, ...) { static bool in_error = false; @@ -69,13 +75,7 @@ static inline bool is_in_range(uint32_t value, uint32_t begin, uint32_t length) return value >= begin && value <= begin + length; } -enum bitness { - BITNESS_8 = 1, - BITNESS_16 = 2, - BITNESS_32 = 4, -}; - -struct read_result { +struct ReadResult { unsigned int result; bool successful; }; @@ -128,39 +128,38 @@ static inline void m68k_read_callback(const uint32_t address, const uint32_t siz } } -static inline struct read_result memory_read( +static inline ReadResult memory_read( const enum bitness bitness, const uint32_t address) { m68k_read_callback(address, bitness); if (is_in_range(address, ROM_START, ROM_SIZE)) { - return read_result{ + return ReadResult{ memory_read_concrete(bitness, g_rom, address - ROM_START), true, }; } else if (is_in_range(address, RAM_START, RAM_SIZE)) { - return read_result{ + return ReadResult{ memory_read_concrete(bitness, g_ram, address - RAM_START), true, }; } else if (is_in_range(address, SOUND_RAM_START, SOUND_RAM_SIZE)) { - return read_result{ + return ReadResult{ memory_read_concrete(bitness, g_sound_ram, address - SOUND_RAM_START), true, }; } else if (is_in_range(address, IO1_START, IO1_SIZE)) { - return read_result{ + return ReadResult{ memory_read_concrete(bitness, g_io1, address - IO1_START), true, }; } else if (is_in_range(address, VDP_START, VDP_SIZE)) { - printf("VDP read u%d 0x%0x\n", bitness * 8, address); - return read_result{ - memory_read_concrete(bitness, g_io2, address - VDP_START), + return ReadResult{ + g_vdp.Read(address - g_vdp.base_address, bitness), true, }; } - return read_result{0, false}; + return ReadResult{0, false}; } static inline void memory_write_concrete( @@ -232,8 +231,7 @@ static inline bool memory_write( } return true; } else if (is_in_range(address, VDP_START, VDP_SIZE)) { - printf("VDP write u%d 0x%0x\n", bitness * 8, address); - memory_write_concrete(bitness, g_io2, address - VDP_START, value); + g_vdp.Write(address - g_vdp.base_address, bitness, value); return true; } return false; @@ -244,7 +242,7 @@ static inline bool memory_write( unsigned int m68k_read_memory_8(const unsigned int address_a) { const uint32_t address = MASK_24(address_a); - const struct read_result ret = memory_read(BITNESS_8, address); + const ReadResult ret = memory_read(BITNESS_8, address); if (!ret.successful) { report_error("Read error u8 @%08x", address); m68k_breakpoint_callback(); @@ -255,7 +253,7 @@ unsigned int m68k_read_memory_8(const unsigned int address_a) unsigned int m68k_read_memory_16(const unsigned int address_a) { const uint32_t address = MASK_24(address_a); - const struct read_result ret = memory_read(BITNESS_16, address); + const ReadResult ret = memory_read(BITNESS_16, address); if (!ret.successful) { report_error("Read error u16 @%08x", address); m68k_breakpoint_callback(); @@ -266,7 +264,7 @@ unsigned int m68k_read_memory_16(const unsigned int address_a) unsigned int m68k_read_memory_32(const unsigned int address_a) { const uint32_t address = MASK_24(address_a); - const struct read_result ret = memory_read(BITNESS_32, address); + const ReadResult ret = memory_read(BITNESS_32, address); if (!ret.successful) { report_error("Read error u32 @%08x", address); m68k_breakpoint_callback(); @@ -277,7 +275,7 @@ unsigned int m68k_read_memory_32(const unsigned int address_a) unsigned int m68k_read_disassembler_16(const unsigned int address_a) { const uint32_t address = MASK_24(address_a); - const struct read_result ret = memory_read(BITNESS_16, address); + const ReadResult ret = memory_read(BITNESS_16, address); if (0 && !ret.successful) exit_error("Disasm read error u16 @0x%08x", address); return ret.result; @@ -286,7 +284,7 @@ unsigned int m68k_read_disassembler_16(const unsigned int address_a) unsigned int m68k_read_disassembler_32(const unsigned int address_a) { const uint32_t address = MASK_24(address_a); - const struct read_result ret = memory_read(BITNESS_32, address); + const ReadResult ret = memory_read(BITNESS_32, address); if (0 && !ret.successful) exit_error("Disasm read error u32 @0x%08x", address); return ret.result; @@ -18,6 +18,12 @@ #define VDP_START (0xC00000) #define VDP_SIZE (0x20) +enum bitness { + BITNESS_8 = 1, + BITNESS_16 = 2, + BITNESS_32 = 4, +}; + struct Breakpoint { uint32_t offset, length; }; @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: Unlicense + */ + +#include "vdp.hpp" + +uint32_t VDP::Read(const uint32_t offset, const enum bitness bitness) +{ + const uint32_t res{}; + if (DEBUG_TRACE_VDP_ACCESS) { + printf( + "VDP r%d%s @0x%08x 0x%0*x\n", + bitness * 8, + (bitness <= 1 ? " " : ""), + base_address + offset, + bitness * 2, + res); + } + if (bitness == BITNESS_32) { + // TODO + } else if (bitness == BITNESS_16) { + // TODO + } + // Ignore 8-bit reads for now + return 0; +} + +void VDP::Write(const uint32_t offset, const enum bitness bitness, const uint32_t value) +{ + if (DEBUG_TRACE_VDP_ACCESS) { + printf( + "VDP w%d%s @0x%08x 0x%0*x", + bitness * 8, + (bitness <= 1 ? " " : ""), + base_address + offset, + bitness * 2, + value); + } + if (bitness == BITNESS_32) { + if (offset == 4 || offset == 6) { + writeControl((value >> 16) & 0xffff); + writeControl(value & 0xffff); + } + } else if (bitness == BITNESS_16) { + if (offset == 4 || offset == 6) { + writeControl(value & 0xffff); + } + } + if (DEBUG_TRACE_VDP_ACCESS) { + printf("\n"); + } + // Ignore 8-bit writes for now +} + +void VDP::writeControl(const uint16_t value) +{ + if (((value >> 13) & 0x7) == 4) { + const uint8_t reg_num = (value >> 8) & 0x1f; + const uint8_t reg_val = value & 0xff; + if (DEBUG_TRACE_VDP_ACCESS) { + printf(": reg 0x%02x w 0x%02x", reg_num, reg_val); + } + _reg[reg_num] = reg_val; + } +} @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: Unlicense + */ + +#pragma once + +#include "bus.hpp" + +#include <cstdio> + +class VDP { + public: + VDP(const uint32_t base_address_a = VDP_START): base_address(base_address_a) {} + uint32_t Read(uint32_t offset, enum bitness); + void Write(uint32_t offset, enum bitness, uint32_t value); + + const uint32_t base_address; + + private: + void writeControl(uint16_t value); + + static constexpr size_t kRegistersCount = 0x18; + uint8_t _reg[kRegistersCount]{}; +}; |