igs/igs_fear.cpp - add IGS027A dump to fearless [tormod, Peter Wilhelmsen, XingXing] (#12553)

* correct clock for XA

igs/pgmcrypt.cpp - properly fix fearless decryption

---------

Co-authored-by: DavidHaywood <[email protected]>

Author: mamehaze

src/mame/igs/igs_fear.cpp

@@ -139,7 +139,7 @@ void igs_fear_state::igs_fear(machine_config &config)
 	ARM7(config, m_maincpu, 50000000/2);
 	m_maincpu->set_addrmap(AS_PROGRAM, &igs_fear_state::main_map);
 
-	MX10EXA(config, m_xa, 10000000); // MX10EXAQC (Philips 80C51 XA) unknown frequency
+	MX10EXA(config, m_xa, 50000000/3); // MX10EXAQC (Philips 80C51 XA)
 
 	screen_device &screen(SCREEN(config, "screen", SCREEN_TYPE_RASTER));
 	screen.set_refresh_hz(60);
@@ -162,8 +162,7 @@ void igs_fear_state::igs_fear(machine_config &config)
 
 ROM_START( fearless )
 	ROM_REGION( 0x04000, "maincpu", 0 ) // Internal rom of IGS027A ARM based MCU
-	// this is taken from superkds, the XOR table required (that is uploaded by this internal ROM) is the same as superkds at least, but actual internal ROM might not be identical
-	ROM_LOAD( "fearless_igs027a.bin", 0x00000, 0x4000, BAD_DUMP CRC(9a8e790d) SHA1(ab020a04a4ed0c0e5ec8c979f206fe57572d2304) ) // sticker marked 'F1'
+	ROM_LOAD( "fearless_igs027a.bin", 0x00000, 0x4000, CRC(2121f01b) SHA1(de44016b590fdcf6bfb63e3f8dbbbd679938fe87) ) // sticker marked 'F1'
 
 	ROM_REGION32_LE( 0x80000, "user1", 0 ) // external ARM data / prg
 	ROM_LOAD( "fearlessp_v-101us.u37", 0x000000, 0x80000, CRC(2522873c) SHA1(8db709877311b6d2796353fc9a44a820937e35c2) )

src/mame/igs/pgmcrypt.cpp

@@ -1453,8 +1453,8 @@ void fearless_decrypt(running_machine &machine)
 		uint16_t x = src[i];
 
 		IGS27_CRYPT1
-		IGS27_CRYPT2_ALT
-		IGS27_CRYPT3
+		// IGS27_CRYPT2
+		IGS27_CRYPT3_ALT2
 		IGS27_CRYPT4
 		// IGS27_CRYPT5
 		IGS27_CRYPT6