diff options
author | 2015-11-08 12:56:12 +0100 | |
---|---|---|
committer | 2015-11-08 12:56:12 +0100 | |
commit | 7c19aac60e12d6f5ea301bdb34d7826a01e0b06f (patch) | |
tree | f310d86aa2c6bfc19d115307dedde4eb0cd52dad /src/devices/bus/generic/rom.cpp | |
parent | a57b46ae933badd7441ce1644711dbb851e2b504 (diff) |
Rename *.c -> *.cpp in our source (nw)
Diffstat (limited to 'src/devices/bus/generic/rom.cpp')
-rw-r--r-- | src/devices/bus/generic/rom.cpp | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/src/devices/bus/generic/rom.cpp b/src/devices/bus/generic/rom.cpp new file mode 100644 index 00000000000..a816040e229 --- /dev/null +++ b/src/devices/bus/generic/rom.cpp @@ -0,0 +1,122 @@ +// license:BSD-3-Clause +// copyright-holders:Fabio Priuli +/*********************************************************************************************************** + + + Generic ROM emulation (for carts and ROM sockets) + + This offers generic access to a ROM + + generic_rom_plain : returns 0xff when the system reads beyond the end of the ROM + generic_rom_linear : maps linearly the ROM in the accessed area (i.e., read offset is masked with (ROM size - 1) ) + + generic_romram_plain : allows support for carts always containing ROM + RAM (e.g. X07) + + + TODO: + - possibly support linear mapping when non-power of 2 ROMs are mapped + + ***********************************************************************************************************/ + + +#include "emu.h" +#include "rom.h" + +//------------------------------------------------- +// constructor +//------------------------------------------------- + +const device_type GENERIC_ROM_PLAIN = &device_creator<generic_rom_plain_device>; +const device_type GENERIC_ROM_LINEAR = &device_creator<generic_rom_linear_device>; +const device_type GENERIC_ROMRAM_PLAIN = &device_creator<generic_romram_plain_device>; + + +generic_rom_device::generic_rom_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source) + : device_t(mconfig, type, name, tag, owner, clock, shortname, source), + device_generic_cart_interface(mconfig, *this) +{ +} + +generic_rom_plain_device::generic_rom_plain_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source) + : generic_rom_device(mconfig, type, name, tag, owner, clock, shortname, source) +{ +} + +generic_rom_plain_device::generic_rom_plain_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : generic_rom_device(mconfig, GENERIC_ROM_PLAIN, "Generic ROM (plain mapping)", tag, owner, clock, "generic_rom_plain", __FILE__) +{ +} + +generic_rom_linear_device::generic_rom_linear_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : generic_rom_device(mconfig, GENERIC_ROM_LINEAR, "Generic ROM (linear mapping)", tag, owner, clock, "generic_rom_linear", __FILE__) +{ +} + +generic_romram_plain_device::generic_romram_plain_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : generic_rom_plain_device(mconfig, GENERIC_ROMRAM_PLAIN, "Generic ROM + RAM (plain mapping)", tag, owner, clock, "generic_romram_plain", __FILE__) +{ +} + + +/*------------------------------------------------- + mapper specific handlers + -------------------------------------------------*/ + +READ8_MEMBER(generic_rom_plain_device::read_rom) +{ + if (offset < m_rom_size) + return m_rom[offset]; + else + return 0xff; +} + +READ16_MEMBER(generic_rom_plain_device::read16_rom) +{ + UINT16 *ROM = (UINT16 *)m_rom; + if (offset < m_rom_size/2) + return ROM[offset]; + else + return 0xffff; +} + +READ32_MEMBER(generic_rom_plain_device::read32_rom) +{ + UINT32 *ROM = (UINT32 *)m_rom; + if (offset < m_rom_size/4) + return ROM[offset]; + else + return 0xffffffff; +} + + +READ8_MEMBER(generic_rom_linear_device::read_rom) +{ + return m_rom[offset % m_rom_size]; +} + +READ16_MEMBER(generic_rom_linear_device::read16_rom) +{ + UINT16 *ROM = (UINT16 *)m_rom; + return ROM[offset % (m_rom_size/2)]; +} + +READ32_MEMBER(generic_rom_linear_device::read32_rom) +{ + UINT32 *ROM = (UINT32 *)m_rom; + return ROM[offset % (m_rom_size/4)]; +} + + +READ8_MEMBER(generic_romram_plain_device::read_ram) +{ + if (offset < m_ram.size()) + return m_ram[offset]; + else + return 0xff; +} + +WRITE8_MEMBER(generic_romram_plain_device::write_ram) +{ + if (offset < m_ram.size()) + m_ram[offset] = data; +} |