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Better autodetection for EF and EFSC ROMs generated by the latest version 

of bB, thanks to RevEng.


git-svn-id: svn://svn.code.sf.net/p/stella/code/trunk@2784 8b62c5a3-ac7e-4cc8-8f21-d9a121418aba
This commit is contained in:
stephena 2013-08-09 21:53:31 +00:00
parent 893bfd4a41
commit 7758e0deb4
3 changed files with 42 additions and 10 deletions
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5
Changes.txt
View File

@ -65,9 +65,12 @@
the ROM, to simulate pressing and releasing the buttons on a
real console.
* Fixed bug when using event remapping; any changes were being saved only
* Fixed bug when using event remapping; changes were being saved only
when launching a ROM from the launcher, not in standalone mode.
* Improved bankswitch autodetection for EF and EFSC ROMs, thanks to
RevEng of AtariAge.
* Added properties database info for "Princess Rescue" ROM.
* For the Linux/UNIX port:

43
src/emucore/Cart.cxx
View File

@ -460,8 +460,8 @@ string Cartridge::autodetectType(const uInt8* image, uInt32 size)
type = "3F";
else if(isProbably4A50(image, size))
type = "4A50";
else if(isProbablyEF(image, size))
type = isProbablySC(image, size) ? "EFSC" : "EF";
else if(isProbablyEF(image, size, type))
; // type has been set directly in the function
else if(isProbablyX07(image, size))
type = "X07";
else
@ -653,7 +653,7 @@ bool Cartridge::isProbablyCV(const uInt8* image, uInt32 size)
bool Cartridge::isProbablyDPCplus(const uInt8* image, uInt32 size)
{
// DPC+ ARM code has 2 occurrences of the string DPC+
uInt8 signature[] = { 0x44, 0x50, 0x43, 0x2B }; // DPC+
uInt8 signature[] = { 'D', 'P', 'C', '+' };
return searchForBytes(image, size, signature, 4, 2);
}
@ -709,11 +709,27 @@ bool Cartridge::isProbablyE7(const uInt8* image, uInt32 size)
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool Cartridge::isProbablyEF(const uInt8* image, uInt32 size)
bool Cartridge::isProbablyEF(const uInt8* image, uInt32 size, const char*& type)
{
// EF cart bankswitching switches banks by accessing addresses 0xFE0
// to 0xFEF, usually with either a NOP or LDA
// Newer EF carts store strings 'EFEF' and 'EFSC' starting at address $FFF8
// This signature is attributed to "RevEng" of AtariAge
uInt8 efef[] = { 'E', 'F', 'E', 'F' };
uInt8 efsc[] = { 'E', 'F', 'S', 'C' };
if(searchForBytes(image+size-8, 8, efef, 4, 1) > 0)
{
type = "EF";
return true;
}
else if(searchForBytes(image+size-8, 8, efsc, 4, 1) > 0)
{
type = "EFSC";
return true;
}
// Otherwise, EF cart bankswitching switches banks by accessing addresses
// 0xFE0 to 0xFEF, usually with either a NOP or LDA
// It's likely that the code will switch to bank 0, so that's what is tested
bool isEF = false;
uInt8 signature[4][3] = {
{ 0x0C, 0xE0, 0xFF }, // NOP $FFE0
{ 0xAD, 0xE0, 0xFF }, // LDA $FFE0
@ -721,8 +737,21 @@ bool Cartridge::isProbablyEF(const uInt8* image, uInt32 size)
{ 0xAD, 0xE0, 0x1F } // LDA $1FE0
};
for(uInt32 i = 0; i < 4; ++i)
{
if(searchForBytes(image, size, signature[i], 3, 1))
return true;
{
isEF = true;
break;
}
}
// Now that we know that the ROM is EF, we need to check if it's
// the SC variant
if(isEF)
{
type = isProbablySC(image, size) ? "EFSC" : "EF";
return true;
}
return false;
}

4
src/emucore/Cart.hxx
View File

@ -335,9 +335,9 @@ class Cartridge : public Device
static bool isProbablyE7(const uInt8* image, uInt32 size);
/**
Returns true if the image is probably a EF bankswitching cartridge
Returns true if the image is probably an EF/EFSC bankswitching cartridge
*/
static bool isProbablyEF(const uInt8* image, uInt32 size);
static bool isProbablyEF(const uInt8* image, uInt32 size, const char*& type);
/**
Returns true if the image is probably an F6 bankswitching cartridge