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(MESS) megadriv: fixed support of SMD files (those with 512k header), broken

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by the recent developments. [Fabio Priuli]

Thanks goes to Carl for providing test cases.
As long as supporting these legacy formats remains easy, I see no reason not to ;)
This commit is contained in:
Fabio Priuli 2013-03-20 13:42:36 +00:00
parent 9ec92e573e
commit 88162e1128
1 changed files with 37 additions and 24 deletions
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61
src/mess/machine/md_slot.c
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@ -389,7 +389,7 @@ int base_md_cart_slot_device::load_list()
*************************************/
/* code taken directly from GoodGEN by Cowering */
static int genesis_is_SMD(unsigned char *buf,unsigned int len)
static int genesis_is_SMD(unsigned char *buf, unsigned int len)
{
if (buf[0x2080] == 'S' && buf[0x80] == 'E' && buf[0x2081] == 'G' && buf[0x81] == 'A')
return 1;
@ -459,47 +459,55 @@ static int genesis_is_SMD(unsigned char *buf,unsigned int len)
int base_md_cart_slot_device::load_nonlist()
{
unsigned char *ROM, *tmpROM;
UINT32 len = m_cart->get_padded_size(length()); // if cart size is not (2^n * 64K), the system will see anyway that size so we need to alloc a bit more space
bool is_smd, is_md;
UINT32 tmplen = length(), offset, len;
// STEP 1: store a (possibly headered) copy of the file and determine its type (SMD? MD? BIN?)
tmpROM = global_alloc_array(unsigned char, tmplen);
fread(tmpROM, tmplen);
is_smd = genesis_is_SMD(&tmpROM[0x200], tmplen - 0x200);
is_md = (tmpROM[0x80] == 'E') && (tmpROM[0x81] == 'A') && (tmpROM[0x82] == 'M' || tmpROM[0x82] == 'G');
// take header into account, if any
offset = is_smd ? 0x200 : 0;
// STEP 2: allocate space for the real copy of the game
// if cart size is not (2^n * 64K), the system will see anyway that size so we need to alloc a bit more space
len = m_cart->get_padded_size(tmplen - offset);
// this contains an hack for SSF2: its current bankswitch code needs larger rom space to work
m_cart->rom_alloc(machine(), (len == 0x500000) ? 0x900000 : len);
// STEP 3: copy the game data in the appropriate way
ROM = (unsigned char *)m_cart->get_rom_base();
tmpROM = global_alloc_array(unsigned char, len);
// STEP 1: determine the file type (SMD? MD? BIN?)
fread(tmpROM, len);
/* is this a SMD file? */
if (genesis_is_SMD(&tmpROM[0x200], len))
if (is_smd)
{
mame_printf_debug("SMD!\n");
for (int ptr = 0; ptr < (len - 0x200) / 0x2000; ptr += 2)
for (int ptr = 0; ptr < (tmplen - 0x200) / 0x2000; ptr += 2)
{
for (int x = 0; x < 0x2000; x++)
{
*ROM++ = *(tmpROM + 0x200 + ((ptr + 1) * 0x2000) + x);
*ROM++ = *(tmpROM + 0x200 + ((ptr + 0) * 0x2000) + x);
ROM[ptr * 0x2000 + x * 2 + 0] = tmpROM[0x200 + ((ptr + 1) * 0x2000) + x];
ROM[ptr * 0x2000 + x * 2 + 1] = tmpROM[0x200 + ((ptr + 0) * 0x2000) + x];
}
}
len -= 0x200;
}
/* is this a MD file? */
else if ((tmpROM[0x80] == 'E') && (tmpROM[0x81] == 'A') && (tmpROM[0x82] == 'M' || tmpROM[0x82] == 'G'))
else if (is_md)
{
mame_printf_debug("MD!\n");
for (int ptr = 0; ptr < len; ptr += 2)
for (int ptr = 0; ptr < tmplen; ptr += 2)
{
ROM[ptr] = tmpROM[(len >> 1) + (ptr >> 1)];
ROM[ptr] = tmpROM[(tmplen >> 1) + (ptr >> 1)];
ROM[ptr + 1] = tmpROM[(ptr >> 1)];
}
}
/* BIN it is, then */
else
{
mame_printf_debug("BIN!\n");
fseek(0, SEEK_SET);
fread(ROM, len);
}
@ -507,16 +515,18 @@ int base_md_cart_slot_device::load_nonlist()
global_free(tmpROM);
// if we allocated a ROM larger that the file (e.g. due to uneven cart size), set remaining space to 0xff
if (len > length())
memset(m_cart->get_rom_base() + length()/2, 0xffff, (len - length())/2);
if (len > (tmplen - offset))
memset(m_cart->get_rom_base() + (tmplen - offset)/2, 0xffff, (len - tmplen + offset)/2);
// STEP 2: determine the cart type (to deal with pirate mappers & eeprom)
m_type = get_cart_type(ROM, length());
// STEP 4: determine the cart type (to deal with sram/eeprom & pirate mappers)
m_type = get_cart_type(ROM, len);
// handle mirroring of ROM, unless it's SSF2 or Pier Solar
if (m_type != SSF2 && m_type != PSOLAR)
m_cart->rom_map_setup(len);
#ifdef LSB_FIRST
unsigned char fliptemp;
// is this really needed nowadays?
@ -889,13 +899,16 @@ const char * base_md_cart_slot_device::get_default_card_software(const machine_c
if (open_image_file(options))
{
UINT32 len = core_fsize(m_file);
UINT32 len = core_fsize(m_file), offset = 0;;
UINT8 *ROM = global_alloc_array(UINT8, len);
int type;
core_fread(m_file, ROM, len);
type = get_cart_type(ROM, len);
if (genesis_is_SMD(&ROM[0x200], len - 0x200))
offset = 0x200;
type = get_cart_type(ROM + offset, len - offset);
slot_string = md_get_slot(type);
global_free(ROM);